Freescale Semiconductor Data Sheet: Technical Data Document Number: MMA9555L Rev. 2.2, 6/2015 MMA9555L Intelligent Motion- MMA9555L Sensing Pedometer The MMA9555L intelligent motion-sensing pedometer is an extension of the MMA955xL intelligent sensor platform. This device incorporates a 3-axis MEMS accelerometer, signal conditioning, data conversion, and a 32-bit microcontroller. This intelligent motion-sensing sensor provides sophisticated pedometer functionality, activity level and six directional orientation monitoring. The integrated functionality of sensor initialization, calibration, data compensation, and computation functions off-loads CPU bandwidth from the system application processor. Therefore, total system power consumption is significantly reduced, because the application processor stays powered down until absolutely needed. In addition, the device can be configured for an autosleep/autowake capability. MMA9555L is available in a plastic LGA package; the device is guaranteed to operate over the extended temperature range of -40 C to +85 C. 16-pin LGA 3 mm x 3 mm x 1 mm Case 2094-01 Features * RGPIO8 / PDB_B VDDA 15 14 1 13 RGPIO7 / AN1 BKGD-MS / RGPIO9 2 12 RGPIO6 / AN0 RESETB 3 11 SCL0 / RGPIO0 / SCLK RGPIO5 / PDB_A / INT_O 4 10 VSS VSS 5 9 Freescale reserves the right to change the detail specifications as may be required to permit improvements in the design of its products. (c) 2015 Freescale Semiconductor, Inc. All rights reserved. 16 VDD 6 7 8 RGPIO3 / SSB * VSSA * Top view RGPIO2 / SDO * * High resolution 3-axis accelerometer with 16-bit ADC (0.061 mg/LSB @ 2 g) Selectable g range (2/4/8 g) and output data rates (488 Hz-3.8 Hz) One slave SPI or I2C interface operating at up to 2 Mbps for communication with the host processor 1.8 V supply voltage low power consumption * 2 A typical current at stop mode * 117 A for pedometer running at active and 92 A at suspend * 87 A when six-direction detection mode Complete built-in firmware for smart sensing intelligence * Real time and preemptive application task scheduling * Command interpreter support command/response and streaming mode * Low-power pedometer with rich output information - Step counting - Speed, distance, calorie count estimation - Activity level (rest, walking, jogging, running) * Six-direction detection output * Extensive set of power-management features and low-power mode * GPIO2-GPIO8 can be used for expanded configurable GPIO functions Minimal external component requirements RGPIO1 / SDA0 / SDI * Pin Connections RGPIO4/INT Typical Applications This low-power, intelligent sensor is optimized for use in portable and mobile consumer products such as: * Pedometers, wearable devices, smart watches, wristband * Sleep monitoring * Smart earphone * Health monitoring Ordering information Part number Firmware Temperature range Package description Shipping MMA9555LR1 Pedometer + Six Directions of Orientation + GPIO Input/Output -40 C to +85 C LGA-16 Tape and reel Related Documentation The MMA9555L device features and operations are described in reference manuals, release notes, and application notes. To find the most-current versions of these documents: 1. 2. Go to the Freescale homepage at: freescale.com. In the Keyword search box at the top of the page, enter the device number MMA9555L. In the Refine Your Results pane on the left, click on the Documentation link. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 2 Freescale Semiconductor, Inc. Contents 1 2 3 4 5 6 7 8 9 10 11 12 Intelligent Sensing Platform Offering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 2.1 Functional Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3 Pin Function Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 System Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Mechanical and Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 3.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2 Pin Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.3 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.4 Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.5 Electrostatic Discharge (ESD) and Latch-up Protection Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.6 General DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.7 Supply Current Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.8 Accelerometer Transducer Mechanical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.9 ADC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.10 ADC Sample Rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.11 AC Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.12 General Timing Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.13 I2C Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.14 Slave SPI Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Communication Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 4.1 Overview of Communication Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.2 Mailbox Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.3 Mailbox Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Version Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 5.1 Reading the version information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Scheduler Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 6.1 Scheduler application elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 6.2 Interrupts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.3 Scheduler configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 6.4 Scheduler status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 GPIO-AppMap Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 7.1 Overview of GPIO-AppMap application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 7.2 GPIO configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Mailbox Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41 8.1 Overview of Mailbox application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 8.2 Mailbox configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 8.3 Mailbox status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 8.4 Reading aggregated data (Legacy mode--Quick read) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Analog Front End Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 9.1 Overview of Analog Front End application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.2 AFE configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 9.3 AFE status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 Data FIFO Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 10.1 Overview of Data FIFO application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 10.2 Modes of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 10.3 Reading process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 10.4 Data FIFO block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 10.5 Data FIFO configuration registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 10.6 Data FIFO status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Event Queue Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 11.1 Overview of Event Queue application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 11.2 Event Queue configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 11.3 Event Queue status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Status Register Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78 12.1 Overview of Status Register application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 3 13 14 15 16 17 18 19 20 12.2 Status Register configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 12.3 Status Register default configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Sleep/Wake Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83 13.1 Overview of Sleep/Wake application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 13.2 Sleep/Wake configuration registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 13.3 Sleep/Wake status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Reset/Suspend/Clear Control Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88 14.1 Overview of Reset/Suspend/Clear Control application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 14.2 Configuration registers for Reset/Suspend/Clear Control applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 14.3 Reset/Suspend/Clear status registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 14.4 Reboot to ROM CI from flash code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 14.5 Reboot to flash code from ROM CI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 MBOX Configuration Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95 15.1 Overview of MBOX Configuration application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 15.2 Normal mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 15.3 Legacy mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 15.4 Configuring mailbox operational mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 15.5 MBOX Configuration memory map and register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Pedometer Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99 16.1 Background and overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 16.2 Functional description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 16.3 Memory-maps and register descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 16.4 Pedometer application examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 GPIO Input/Output Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114 17.1 Overview of GPIO Input/Output application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 17.2 Memory maps and register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 17.3 GPIO Input/Output configuration register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 17.4 GPIO Input/Output Status register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 17.5 GPIO Input/Output application examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Six-Direction Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119 18.1 Overview of the Six-Direction application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 18.2 Memory maps and register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 18.3 Six Direction configuration register descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 18.4 Six Direction Status register descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Sample operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123 19.1 Read pedometer status variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.2 Read pedometer configuration variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.3 Write pedometer configuration variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.4 Read GPIO Input/output status variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.5 Read GPIO Input/output configuration variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.6 Write GPIO Input/output configuration variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.7 Read Six direction status variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.8 Read Six direction configuration variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 19.9 Write Six direction configuration variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 19.10 Reset pedometer configuration variables to their defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 19.11 Enable/disable the Pedometer application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 19.12 Configure the AFE range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 19.13 Configure output interrupt: Activity change on GPIO6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 19.14 Configure output interrupt: Step change on GPIO7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 19.15 Configure output interrupt: Suspend change on GPIO8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 19.16 Configure output interrupt: Merged flags on GPIO6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 19.17 Configure output interrupt: Every 10 steps on GPIO7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 19.18 Configure output interrupt: Device direction change on GPIO6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 19.19 Wake up from Deep Sleep (Stop No Clock mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126 20.1 Footprint and pattern information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 20.2 Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 20.3 Tape and reel information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 20.4 Package Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 4 Freescale Semiconductor, Inc. 1 Intelligent Sensing Platform Offering Freescale has a broad offering of MMA955xL devices. The MMA9550L, MMA9551L, MMA9553L, and MMA9555L devices can function immediately as shipped. They have an internal command interpreter and applications scheduler. These devices can interact directly with the users' host system. The MMA9550L, MMA9551L, MMA9553L and MMA9559L devices are programmable with additional user application software. These devices have a variety of user flash and RAM memory space available. The MMA9555L is provided with complete factory build application specific software, no additional user software programming in the device is needed. NOTE The information and specifications provided in this data sheet are specific to the MMA9555L. Information for the other devices can be found in the MMA955xL collateral and datasheet. Table 1. Freescale Intelligent Sensing Product Comparison Feature - Device MMA9550L MMA9551L MMA9553L Key elements Motion sensing Gesture sensing ADC resolution (bits) 10,12,14,16 bits 10,12,14,16 bits 10,12,14,16 bits g measurement ranges Pedometer MMA9555L MMA9559L Pedometer + six-direction orientation High flexibility + GPIO Input/Output 10,12,14,16 bits 10,12,14,16 bits 2 g, 4 g, 8 g 2 g, 4 g, 8 g 2 g, 4 g, 8 g 2 g, 4 g, 8 g 2 g, 4 g, 8 g Real-time and preemptive scheduling Yes Yes Yes Yes No Event management No No No No Yes * Normal mode Yes Yes Yes Yes No * Legacy mode Yes Yes Yes Yes No * Streaming mode Yes Yes Yes Yes No * 100 Hz BW anti-aliasing Yes Yes Yes Yes No * 50 Hz BW anti-aliasing Yes Yes Yes Yes No * g-mode-dependent resolution Yes Yes Yes Yes Yes * Absolute value Yes Yes Yes Yes No * Low-pass filter Yes Yes Yes Yes No * High-pass filter Yes Yes Yes Yes No * Data-ready interrupt Yes Yes Yes Yes Yes * High g/Low g No Yes No No No * Tilt No Yes No No No Slave Port Command Interpreter Front-end processing Gesture applications MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 5 Table 1. Freescale Intelligent Sensing Product Comparison (Continued) Feature - Device MMA9550L MMA9551L MMA9553L MMA9555L MMA9559L * Portrait/Landscape No Yes No No No * Programmable orientation No Yes No No No * Tap/Double-tap No Yes No No No * Freefall No Yes No No No * Motion No Yes No No No * Data FIFO Yes Yes Yes Yes No * Event queue Yes Yes Yes Yes No * Inter-process FIFO No No No No Yes * Run and Stop on idle Yes Yes Yes Yes Yes * Run and No stop Yes Yes Yes Yes Yes * Stop NC Yes Yes Yes Yes Yes * Auto-Wake / Auto-Sleep / Doze Yes Yes Yes Yes No Data-management daemons Yes Yes Yes Yes Yes * Step count No No Yes Yes No * Distance No No Yes Yes No * Adaptive distance No No Yes Yes No * Activity monitor No No Yes Yes No Six Directional Orientation No No No Yes No GPIO management No No No Yes No Data-storage modules Power-control module Pedometer applications MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 6 Freescale Semiconductor, Inc. 2 General Description 2.1 Functional Overview The MMA9555L is an intelligent motion sensing pedometer, it consists of a 3-axis, MEMS accelerometer and a mixed-signal ASIC with an integrated, 32-bit CPU. The mixed-signal ASIC can be utilized to measure and condition the outputs of the MEMS accelerometer, internal temperature sensor, or a differential analog signal from an external device. The calibrated, measured sensor outputs can be read via the slave I2C or SPI port and utilized internally within the MMA9555L to provide advanced intelligent motion detection outputs like pedometer step count, activity level and six directional orientation detections which can be accessed via the slave I2C or SPI port. INT_O Control and mailbox RESET BDM BKGD SIM SPI slave INT DBG SCLK SDI SDO SSB SCL0/RGPIC0/SCLK Analog Front End (AFE) X axis 32 bit CPU Y axis Z axis SDA0/RGPIO1/SDI RGPIO2/SCL1/SDO Temp Sensor C to V ADC ROM SCL0 SDA0 AN0 AN1 RGPIO3/SDA1/SSB RGPIO CLKGEN INTC 2 I C slave RGPIO4/INT RGPIO5/PDB_A/INT_O RGPIO6/AN0/TPMCH0 2 I C Master SCL1 SDA1 RGPIO7/AN1/TPMCH1 RGPIO8/PDB_B Flash Programmable delay block PDB_A PDB_B BKGD/MS/RPGPIO9 RAM VDD Two-channel, 16-bit TPMCH0 Timer / PWM module TPMCH1 VDDA VSS VSS 16-bit Modulo timer module VSSA Figure 1. MMA9555L block diagram A block-level view is shown in Figure 1 with building blocks of devices and built-in applications summarized at a high level. The analog/mixed-mode subsystem associated with a digital engine is composed of: * The analog subsystem is composed of: * A 3-axis transducer that is an entirely passive block including the MEMS structures. * An Analog Front End (AFE) with the following: - A capacitance-to-voltage converter - An analog-to-digital converter - A temperature sensor * The digital subsystem is composed of: * A 32-bit CPU * Memory: RAM, ROM, and flash * Rapid GPIO (RGPIO) port-control logic MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 7 Pinout - - - I2C or SPI slave interface System Integration Module (SIM) Clock-Generation Module The slave interfaces (either SPI or I2C) operate independently of the CPU subsystem. They can be accessed at any time, including while the device is in low-power, deep-sleep mode. 2.2 Pinout BKGD-MS / RGPIO9 VDDA 1 RGPIO8 / PDB_B VDD VSSA The package pinout definition for this device is designed as a superset of functions on Freescale's other MMA955xL offerings. All pins on the device are utilized and many are multiplexed. 16 15 14 13 RGPIO7 / AN1 2 12 RGPIO6 / AN0 RESETB 3 11 RGPIO5 / PDB_A / INT_O SCL0 / RGPIO0 / SCLK 4 10 VSS VSS 5 7 8 RGPIO1 / SDA0 / SDI RGPIO2 / SDO RGPIO3 / SSB 9 6 RGPIO4/INT Figure 2. Device pinout (top view) 2.2.1 Pin Functions The following table summarizes functional options for each pin on this device. Table 2. Pin functions Pin # Pin Name 1 VDD 2 BKGD / MS / RGPIO9 3 RESETB 4 Description Digital power supply Background-debug / Mode select / RGPIO9 Active-low reset. RESETB is an open-drain, bidirectional pin. By default, the output function is not on. Must be pulled to VDD via resistor at startup. After startup, Reset may be asserted low to reset the device. SCL0 / RGPIO0 / SCLK Serial clock for slave I2C / RGPIO0 / Serial clock for slave SPI 5 VSS 6 SDA0 / RGPIO1 / SDI 7 RGPIO2 / SDO RGPIO2 / SPI serial data output 8 RGPIO3 / SBB RGPIO3 / SPI slave select. RGPIO3 / SSB = Low at startup selects SPI. High at startup selects I2C. Digital ground Serial data for slave I2C / RGPIO1 / SPI serial data input MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 8 Freescale Semiconductor, Inc. Pin Function Descriptions Table 2. Pin functions (Continued) Pin # Pin Name 9 RGPIO4/INT RGPIO4 / Interrupt input 10 RESERVED Must be connected to VSS ground externally 11 RGPIO5 / INT_O 12 RGPIO6 / AN0 RGPIO6 / ADC Input 0 13 RGPIO7 / AN1 RGPIO7 / ADC Input 1 14 VDDA 15 RGPIO8 16 VSSA 2.3 Description RGPIO5 or INT_O slave-port interrupt output. INT_O can only output interrupts from the COCO bit. For setting sensor data output interrupts, use RGPIO6-RGPIO9. Analog power RGPIO8 Analog ground Pin Function Descriptions This section provides a brief description of the various pin functions available on the MMA9555L pedometer sensor. Ten of the device pins are multiplexed with Rapid GPIO (RGPIO) functions. VDD and VSS: Digital power and ground. VDD is nominally 1.8 V. VDDA and VSSA: Analog power and ground. VDDA is nominally 1.8 V. To optimize performance, the VDDA line can be filtered to remove any digital noise that might be present on the 1.8 V supply. (See Figure 3 and Figure 4.) RESETB: The RESETB pin is an open-drain, bidirectional pin with an internal, weak, pullup resistor. At start-up, it is configured as an input pin, but also can be programmed to become bidirectional. By default, the output function is not on. Using this feature, the MMA9555L device can reset external devices for any purpose other than power-on reset. Reset must be pulled high at power up to boot to Application code space. If low, it will boot to ROM code. After startup, Reset may be asserted to reset the device. The total external capacitance to ground has to be limited when using RESETB-pin, output-drive capability. For more details, see the "System Integration Module" chapter of the MMA955xL Intelligent, Motion-Sensing Platform Hardware Reference Manual (MMA955xLHWRM), listed in "Related Documentation" on page 2. Slave I2C port: SDA0 and SCL0: These are the slave-I2C data and clock signals, respectively. The MMA9555L device can be controlled via the serial port or via the slave SPI interface. Analog-to-Digital Conversion: AN0, AN1: The on-chip ADC can be used to perform a differential, analog-to-digital conversion based on the voltage present across pins AN0(-) and AN1(+). Conversions for these pins are at the same Output Data Rate (ODR) as the MEMS transducer signals. Input levels are limited to 1.8 V differential. Rapid General Purpose I/O: RGPIO[9:0]: The Intelligent Pedometer has a feature called Rapid GPIO (RGPIO). This is a 16-bit, input/output port with single-cycle write, set, clear, and toggle functions available to the CPU. The MMA9555L device brings out the lower 10 bits of that port as pins of the device. At reset, all of the RGPIO pins are configured as input pins, although pin muxing does reassign some pins to non-RGPIO function blocks. Pullups are disabled. RGPIO[9:6] can be set as interrupt pins for most interrupt sources. INT_O can only output interrupts from the COCO bit. For setting sensor data output interrupts, use RGPIO6-RGPIO9. RGPIO3 / SBB = Low at startup selects SPI. High at startup selects I2C. RGPIO[5] or INT_O can only output interrupts from the COCO bit. For setting sensor data output interrupts, use RGPIO6-RGPIO9. RGPIO[9] is connected to BKGD/MS. RGPIO[1:0] SDA0 and SCL0 are connected at reset. Interrupts: INT: This input pin can be used to wake the CPU from a deep-sleep mode. It can be programmed to trigger on either rising or falling edge, or high or low level. This pin operates as a Level-7 (high-priority) interrupt. Debug/Mode Control: BKGD/MS: At start-up, this pin operates as mode select. If this pin is pulled high during start up, the CPU will boot normally and run code. If this pin is pulled low during start-up, the CPU will boot into active Background-Debug Mode (BDM). In BDM, this pin operates as a bidirectional, single-wire, background-debug port. It can be used by development tools for downloading code into on-chip RAM and flash and to debug that code. There is an internal pullup resistor on this pin, therefore, It may be left floating. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 9 System Connections Slave SPI Interface: SCLK, SDI, SDO and SBB: These pins control the slave SPI clock, data in, data out, and slave-select signals, respectively. The MMA9555L platform can be controlled via this serial port or via the slave-I2C interface. SBB has a special function at startup that selects the Slave interface mode. Low at startup selects SPI and high selects I2C. INT_O: The slave-port output interrupt pin can be used to flag the host when a response to a command is available to read on the slave port. INT_O can only output interrupts from the COCO bit. For sensor data output interrupts, use RGPI06-RGPIO9. 2.4 2.4.1 System Connections Power Sequencing An internal circuit powered by VDDA provides the device with a power-on-reset signal. In order for this signal to be properly recognized, it is important that VDD is powered up before or simultaneously with VDDA. The voltage potential between VDD and VDDA must not be allowed to exceed the value specified in Table 6 on page 14. 2.4.2 * * * * * * * * * * Layout Recommendations Provide a low-impedance path from the board power supply to each power pin (VDD and VDDA) on the device and from the board ground to each ground pin (VSS and VSSA). Place 0.01 to 0.1 F capacitors as close as possible to the package supply pins to meet the minimum bypass requirement. The recommended bypass configuration is to place one bypass capacitor on each of the VDD/VSS pairs. VDDA/VSSA ceramic and tantalum capacitors tend to provide better tolerances. Capacitor leads and associated printed-circuit traces that connect to the chip VDD and VSS (GND) pins must be as short as possible. Bypass the power and ground with a capacitor of approximately 1 F and a number of 0.1-F ceramic capacitors. Minimize PCB trace lengths for high-frequency signals. This is especially critical in systems with higher capacitive loads that could create higher transient currents in the VDD and VSS circuits. Take special care to minimize noise levels on the VDDA and VSSA pins. Use separate power planes for VDD and VDDA and separate ground planes for VSS and VSSA. Connect the separate analog and digital power and ground planes as close as possible to power supply outputs. If both analog circuit and digital circuits are powered by the same power supply, it is advisable to connect a small inductor or ferrite bead in series with both the VDDA and VSSA traces. Physically separate the analog components from noisy digital components by ground planes. Do not place an analog trace in parallel with digital traces. It is also desirable to place an analog ground trace around an analog signal trace to isolate it from digital traces. Provide an interface to the BKGD/MS pin if in-circuit debug capability is desired. Ensure that resistors RP1 and RP2, in the following figure, match the requirements stated in the I2C standard. For the shown configuration, the value of 4.7 k would be appropriate. 2.4.3 MMA9555L Pedometer Sensor as an Intelligent Slave I2C pullup resistors, and a few bypass capacitors are all that are required to attach this device to a host platform. The basic configurations are shown in the following two figures. In addition, the RGPIO pins can be programmed to generate interrupts to a host platform in response to the occurrence of real-time application events. In this case, the pins should be routed to the external interrupt pins of the CPU. NOTE Immediately after a device reset, the state of pin number 8 (RGPIO3 / SDA1 / SSB functions) is used to select the slave port interface mode. This implies important rules in the way the host controller or, more generally, the complete system should be handling this pin. First of all, whenever a reset occurs on the MMA9555L, the RGPIO3 pin level shall be consistent with the interface mode of operation. This is particularly important if this pin is driven from external devices. If the RGPIO3 level does not match the current mode of operation, an alternate mode is selected and communication with the host is lost. If I2C mode is used, a good practice is to tie RGPIO3 to a pull-up resistor so that it defaults to high level. When using I2C mode for the slave interface, the RGPIO3 pin plays two roles: RGPIO3 and mode selection. When the MMA9555L is powered on and the mode selection is I2C, the RGPIO3 pin is released as a GPIO pin. The default setting of RGPIO3 is as an output pin and MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 10 Freescale Semiconductor, Inc. System Connections output low. In order to reduce the leakage current on the pull-up resistor, a large resistor value can be used or RGPIO3 can be set as an input pin. When using SPI mode for the slave interface, the situation is more complex as the same pin plays two roles: SSB and mode selection. Moreover, after a SPI read or write operation, the SSB line returns to high level. Consequently, if the host is sending a command to the MMA9555L that induces a subsequent reset, immediately after the write transaction, the host shall force the SSB line to low level so that SPI mode is still selected after reset. The duration for the SSB line to be kept low typically depends on the latency between the write transaction and the execution of the reset command. Such latency can be significant for the MMA9555L pedometer firmware as the Command Interpreter and Scheduler Application are running at 30 Hz which gives a 33 ms typical latency. The rule obviously applies also when a hardware reset is issued by the host through MMA9555L pin number 3 (RESETB active low). Again the host has to drive the SSB line low prior to release of the hardware reset line to high level, which triggers immediate MMA9555L reset and boot sequence. Keeping the SSB line low for a 1 ms duration (after RESETB is released) is enough for the MMA9555L slave device to re-boot into SPI mode. Quiet VDDA for best performance 1.8 V 1.8 V 1.8 V 2 3 1.8 V R3 4.7 K 2 R4 4.7 K 14 15 VDD IO7 / AN1 BKGD / MS / IO9 IO6 / AN0 RESETB 4 SCL0 / IO0 / SCLK 5 VSS 7 6 12 * IO5 / PDB_A / INT_O 11 VSS 10 IO4 / INT I C_CLK 13 9 IO3 / SSB 1 8* R1 4.7 K SDA0 / IO1 / SDI R2 4.7 K C1* * C1 is not necessary for 1 F all implementations, but is recommended as good design practice for achieving low noise operation. VDDA 1.8 V IO8 / PDB_B VSSA U1 MMA955X IO2 / SDO C3 0.1 F 16 C2 0.1 F INT_OUT * IO5 can only be configured as COCO bit interrupt. For most interrupt sources, use IO6-IO9. *See the NOTE in this section. 2 I C_DATA Figure 3. MMA9555L Pedometer Sensor as an I2C slave MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 11 System Connections Quiet VDDA for best performance 1.8 V 1.8 V INT_OUT 1.8 V 14 15 BKGD / MS / IO9 IO6 / AN0 RESETB 4 SCL0 / IO0 / SCLK 5 VSS SPI_CLK 6 SPI_DI (MOSI) SPI_DO (MISO) 13 12 * IO5 / PDB_A / INT_O 11 VSS 10 IO4 / INT INT_COCO 9 * IO5 can only be configured as COCO bit interrupt. For most interrupt sources, use IO6-IO9. IO3 / SSB 3 IO7 / AN1 IO2 / SDO 2 VDD 8* 1 SDA0 / IO1 / SDI R1 4.7 K R2 4.7 K VDDA 1.8 V IO8 / PDB_B VSSA 16 U1 MMA955X 7 C3 0.1 F C1* * C1 is not necessary for 1 F all implementations, but is recommended as good design practice for achieving low noise operation. C2 0.1 F * See the NOTE in this section. SPI_EN Figure 4. MMA9555L Pedometer Sensor as an SPI slave 2.4.4 Sensing Direction and Output Response Figure 5 shows the device's default sensing direction when measuring gravity in a static manner from the six standard orientation modes: portrait up/down, landscape left/right and back/front. Side view Top view Back Portrait Up Pin 1 Xout @ 0 g Yout @ 0 g Zout @ -1 g Gravity Xout @ 0 g Yout @ -1 g Zout @ 0 g Landscape Right Landscape Left Xout @ -1 g Yout @ 0 g Zout @ 0 g Front Portrait Down Xout @ 0 g Yout @ 1 g Zout @ 0 g Xout @ 0 g Yout @ 0 g Zout @ 1 g Xout @ 1 g Yout @ 0 g Zout @ 0 g +X +Z +Y Figure 5. Sensing direction and output response MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 12 Freescale Semiconductor, Inc. 3 Mechanical and Electrical Specifications This section contains electrical specification tables and reference timing diagrams for the MMA9555L device, including detailed information on power considerations, DC/AC electrical characteristics, and AC timing specifications. 3.1 Definitions Cross-axis sensitivity The proportionality constant that relates a variation of accelerometer output to cross acceleration. This sensitivity varies with the direction of cross acceleration and is primarily due to misalignment. Full range The algebraic difference between the upper and lower values of the input range. Refer to the input/ output characteristics. Hardware compensated Sensor modules on this device include hardware-correction factors for gain and offset errors that are calibrated during factory test using a least-squares fit of the raw sensor data. Linearity error The deviation of the sensor output from a least-squares linear fit of the input/output data. Nonlinearity The systematic deviation from the straight line that defines the nominal input/output relationship. Pin group The clustering of device pins into a number of logical pin groupings to simplify and standardize electrical data sheet parameters. Pin groups are defined in Section 3.2, "Pin Groups". Software compensated Freescale's advanced nonlinear calibration functions that--with the first-order hardware gain and offset calibration features--improve sensor performance. Warm-up time The time from the initial application of power for a sensor to reach its specified performance under the documented operating conditions. 3.2 Pin Groups The following pin groups are used throughout the remainder of this section. Group 1 RESETB Group 2 RESERVED Group 3 RGPIO[9:0] 3.3 Absolute Maximum Ratings Absolute maximum ratings are the limits the device can be exposed to without permanently damaging it. Absolute maximum ratings are stress ratings only; functional operation at these ratings is not guaranteed. Exposure to absolute maximum ratings conditions for extended periods may affect reliability. This device contains circuitry to protect against damage due to high static voltage or electrical fields. It is advised, however, that normal precautions be taken to avoid application of any voltages higher than maximum-rated voltages to this high-impedance circuit. Reliability of operation is enhanced if unused inputs are tied to an appropriate logic voltage level (for instance, either VSS or VDD). Table 3. Absolute maximum ratings Rating Symbol Minimum Maximum Unit Digital supply voltage VDD -0.3 2.0 V Analog supply voltage VDDA -0.3 2.0 V Voltage difference, VDD to VDDA VDD - VDDA -0.1 0.1 V Voltage difference, VSS to VSSA VSS - VSSA -0.1 0.1 V Input voltage VIn -0.3 VDD + 0.3 V Input/Output pin-clamp current IC -20 20 mA Output voltage range (Open-Drain Mode) VOUTOD -0.3 VDD + 0.3 V Storage temperature Tstg -40 125 C Mechanical shock SH -- 5k g MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 13 Operating Conditions 3.4 Operating Conditions Table 4. Nominal operating conditions Rating 3.5 Symbol Min Typ Max Unit Digital supply voltage VDD 1.71 1.8 1.89 V Analog supply voltage VDDA 1.71 1.8 1.89 V Voltage difference, VDD to VDDA VDD - VDDA -0.1 -- 0.1 V Voltage difference, VSS to VSSA VSS - VSSA -0.1 -- 0.1 V Input voltage high VIH 0.7 * VDD -- VDD+0.1 V Input voltage low VIL VSS - 0.3 -- 0.3*VDD V Operating temperature TA -40 25 85 C Electrostatic Discharge (ESD) and Latch-up Protection Characteristics Table 5. ESD and latch-up protection characteristics Rating Symbol Value Unit VHBM 2000 V Machine Model (MM) VMM 200 V Charge Device Model (CDM) VCDM 500 V ILAT 100 mA Human Body Model (HBM) Latch-up current at 85 C 3.6 General DC Characteristics Table 6. DC characteristics(1) Symbol Condition(s)(2) Min Typ Max Unit Output voltage high * Low-drive strength * High-drive strength VOH Pin Groups 1 and 3 ILOAD = -2 mA ILOAD = -3 mA VDD - 0.5 -- -- V Output voltage low * Low-drive strength * High-drive strength VOL Pin Groups 1 and 3 ILOAD = 2 mA ILOAD = 3 mA -- -- 0.5 V Output-low current Max total IOL for all ports IOLT -- -- -- 24 mA Output-high current Max total IOH for all ports IOHT -- -- -- 24 mA Input-leakage current |IIN| Pin Group 2 Vin = VDD or VSS -- 0.1 1 A Hi-Z (off-state) leakage current |IOZ| Pin Group 3 input resistors disabled Vin = VDD or VSS -- 0.1 1 A Pullup resistor RPU when enabled 17.5 -- 52.5 k Power-on-reset voltage VPOR -- -- 1.50 -- V VPOR-hys -- -- 100 -- mV CIN -- -- 7 -- pF COUT -- -- 7 -- pF Characteristic Power-on-reset hysteresis Input-pin capacitance Output-pin capacitance 1. 2. All conditions at nominal supply: VDD = VDDA = 1.8 V. Pin groups are defined in "Pin Groups" on page 13. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 14 Freescale Semiconductor, Inc. Supply Current Characteristics 3.7 Supply Current Characteristics Table 7. Supply current characteristics(1) Characteristic Supply current in STOPNC mode Supply current in STOPSC mode Supply current in RUN mode(2) 1. 2. Symbol Condition(s) Min Typ Max Unit IDD-SNC Internal clocks disabled -- 2 -- A IDD-SSC Internal clock in slow-speed mode -- 15 -- A IDD-R Internal clock in fast mode -- 3.1 -- mA All conditions at nominal supply: VDD = VDDA = 1.8 V. Total current with the analog section active, 16 bits ADC resolution selected, MAC unit used and all peripheral clocks enabled. 3.8 Accelerometer Transducer Mechanical Characteristics Table 8. Accelerometer characteristics Characteristic Symbol Condition(s) 2g 1.8 2 2.2 AFR 4g 3.6 4 4.4 8g 7.2 8 8.8 2g -- 0.061 -- 4g -- 0.122 -- 8g -- 0.244 -- -100 -- +100 2g -- 0.25 -- 4g -- 0.5 -- 8g -- 1 -- Full range Sensitivity/resolution ASENS Min Typ Max Unit g mg/LSB 2g Zero-g level offset accuracy (Pre-board mount) OFFPBM 4g mg 8g Nonlinearity Best fit straight line ANL % AFR Sensitivity change vs.temperature TCSA 2g -- 0.17 -- %/C Zero-g level change vs. temperature(1) TCOff -- -- 1.9 -- mg/C OFFBM 4g -100 -- +100 mg -- -- ODR/2 -- Hz Zero-g Level offset accuracy (Post-board mount) 2g 8g Output data bandwidth Output noise BW Noise Cross-axis sensitivity 1. -- 2 g, ODR = 488 Hz -- 100 -- g/sqrt(Hz) 8 g, ODR = 488 Hz -- 120 -- g/sqrt(Hz) -- -5 -- 5 % Relative to 25 C. 3.9 ADC Characteristics Table 9. ADC characteristics(1) Characteristic Symbol Condition(s) Min Typ Max Unit Input voltage VAI Voltage at AN0 or AN1 0.2 -- 1.1 V Differential input voltage VADI AN1 - AN0 -0.9 -- 0.9 V Full-scale range VFS -- -- 1.8 -- V Programmable resolution RES -- 10 14 16 Bits MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 15 ADC Sample Rates Table 9. ADC characteristics(1) (Continued) Characteristic Symbol Condition(s) Min Typ Max Unit tc -- -- 207 -- s Integral nonlinearity INL Full scale -- 15 -- LSB Differential nonlinearity DNL -- -- 2 -- LSB IIA -- -- -- 2 A Conversion time @ 14-bits resolution (Three-sample frame) Input leakage 1. All conditions at nominal supply: VDD = VDDA = 1.8 V and RES = 14, unless otherwise noted. 3.10 ADC Sample Rates The MMA9555L internal ADC supports the following sample output rates, while the pedometer application uses 30.52 fps as default: * 488.28 frames per second (fps) * 244.14 fps * 122.07 fps * 61.04 fps * 30.52 fps * 15.26 fps * 7.63 fps * 3.81 fps 3.11 AC Electrical Characteristics Tests are conducted using the input levels specified in Table 4 on page 14. Unless otherwise specified, propagation delays are measured from the 50-percent to 50-percent point. Rise and fall times are measured between the 10-percent and 90-percent points, as shown in the following figure. Low VIH Input Signal High 90% 50% 10% Midpoint1 VIL Fall Time Rise Time Note: The midpoint is VIL + (VIH - VIL)/2. Figure 6. Input signal measurement references The subsequent figure shows the definitions of the following signal states: * Active state, when a bus or signal is driven and enters a low-impedance state * Three-stated, when a bus or signal is placed in a high-impedance state * Data Valid state, when a signal level has reached VOL or VOH * Data Invalid state, when a signal level is in transition between VOL and VOH Data1 Valid Data1 Valid Data1 Data3 Valid Data2 Data3 Data 3-stated Data Invalid State Data Active Data Active Figure 7. Signal states MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 16 Freescale Semiconductor, Inc. General Timing Control 3.12 General Timing Control Table 10. General timing characteristics(1) Characteristic VDD rise time POR release delay (2) Warm-up time Frequency of operation System clock period Full/Slow clock ratio Oscillator frequency absolute accuracy @ 25 C Oscillator frequency variation over temperature (-40 C to 85 C vs. ambient) Minimum RESET assertion duration 1. 2. 3. Symbol Condition(s) Min Typ Max Unit Trvdd TPOR 10% to 90% Power-up -- 0.35 -- 1 1.5 TWU From STOPNC -- 7 -- FOPH FOPL tCYCH tCYCL -- Full Speed Clock Slow Clock Full Speed Clock Slow Clock -- -- -- -- -- -- 8 62.5 125 16 128 -- -- -- -- -- ms ms sample periods MHz KHz ns s -- Full Speed Clock -5 -- +5 % -- Slow Clock -6 -- +6 % tRA -- 4T(3) -- -- -- All conditions at nominal supply: VDD = VDDA = 1.8 V This is the time measured from VDD = VPOR until the internal reset signal is released. In the formulas, T = 1 system clock cycle. In full speed mode, T is nominally 125 ns. In slow speed mode, T is nominally 16 s. 3.13 I2C Timing This device includes a slave I2C module that can be used to control the sensor and can be active 100 percent of the time. SDA tf tLOW tf tSU; DAT tr tSP tHD; STA tr tBUF SCL S tHD; STA tHD; DAT Figure 8. 3.13.1 tSU; STA tHIGH I2C tSU; STO SR P S standard and fast-mode timing Slave I2C Table 11. I2C Speed Ranges Max Baud Rate (fSCL) Min Bit Time Min SCL Low (tLOW) Min SCL High (tHIGH) Min Data setup Time (tSU; DAT) Min/Max Data Hold Time (tHD; DAT) Standard 100 kHz 10 s 4.7 s 4 s 250 ns 0 s/3.45 s(1) Fast 400 kHz 2.5 s 1.3 s 0.6 s 100 ns 0 s/0.9 s(1) 1 MHz 1 s 500 ns 260 ns 50 ns 0 s/0.45 s(1) 2.0 MHz 0.5 s 200 ns 200 ns 10 ns(2) 0 ns/70 ns (100 pf)(1) Mode Fast + High-speed supported 1. 2. The maximum tHD; DAT must be at least a transmission time less than tVD;DAT or tVD;ACK. For details, see the I2C standard. Timing met with IFE = 0, DS = 1, and SE = 1. Refer to the chapter titled Port Controls in the MMA955xL Intelligent, Motion-Sensing Platform Hardware Reference Manual (MMA955xLHWRM), listed in "Related Documentation" on page 2. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 17 Slave SPI Timing 3.14 Slave SPI Timing Table 12. Slave SPI timing Time Period Function (1) -- 1. Symbol Min Max Unit fop 0 FOPH/4 Hz Operating frequency 1 SCLK period tSCLK 4 -- tCYCH 2 Enable lead time tLead 0.5 -- tCYCH 3 Enable lag time 4 Clock (SCLK) high or low time 5 6 7 8 tLag 0.5 -- tCYCH tWSCLK 200 -- ns Data-setup time (inputs) tSU 15 -- ns Data-hold time (inputs) tHI 25 -- ns Access time ta -- 25 ns SDO-disable time tdis -- 25 ns 9 Data valid (after SCLK edge) tv -- 25 ns 10 Data-hold time (outputs) tHO 0 -- ns 11 Rise time Input Output tRI tRO -- -- 25 25 ns ns 12 Fall time Input Output tFI tFO -- -- 25 25 ns ns Time period from Figure 9. SS (INPUT) 1 11 12 3 SCLK (INPUT) 2 4 4 8 7 SDO (OUTPUT) SLAVE 5 SDI (INPUT) 9 MSB OUT BIT 6 . . . 1 < 10 10 SLAVE LSB OUT SEE NOTE 6 MSB IN BIT 6 . . . 1 LSB IN NOTE: 1. Not defined but normally MSB of character just received. Figure 9. SPI slave timing MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 18 Freescale Semiconductor, Inc. 4 Communication Interface 4.1 Overview of Communication Interface All access to the MMA9555L is made via the slave, serial Communication Interface that is part of the hardware and firmware infrastructure of the platform. The communication occurs in Command/Response (Normal) or Quick Read (Legacy) mode. Commands are sent from the host and through the slave communications port (either SPI or I2C). The Communication Interface interprets the command and sends the data to the correct application. The application executes the command and returns with data, if requested with the command response. It also responds with error codes when appropriate. The Communications Interface works with the Mailbox application to implement the command and response. The mailboxes' functionality is configured with two applications: the MBOX Configuration application (APP_ID = 0x18) and the MBOX application (APP_ID = 0x04). 4.2 Mailbox Interface Commands are received through a set of 32 mailboxes that are 32 registers arranged consecutively to provide addressable memory regions. Each mailbox can hold one byte of data. After a command has completed, the Communication Interface writes the results to the mailboxes and the results (response out) are retrieved by the host via the SPI or the I2C slave interface. The following figure shows the structure of the data packet when writing one byte into a specific mailbox. Device Address = 0x4C S 1 0 0 1 1 0 Start R/W 0 0 Data Byte Destination Mailbox Address A A7 A6 A5 A4 A3 A2 A1 A0 A Acknowledge Stop D7 D6 D5 D4 D3 D2 D1 D0 A Acknowledge P Acknowledge Figure 10. I2C interface writing one byte of information to a mailbox If the transaction contains more than one data byte, the internal-destination mailbox address is automatically incremented so that the incoming byte is placed in the next mailbox. For mailbox addresses greater than 31 bytes or for transactions where the mailbox address auto-increments past mailbox 31, the destination address wraps back to the start of the mailbox addresses. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 19 Mailbox Usage 4.2.1 Mailbox Timing Clock Data Data values S S Start A Acknowledge P Stop 98 00 A A 00 A 00 A P Figure 11. I2C timing diagram Enable Clock MOSI MISO MOSI values 80 00 00 MISO values FF FF FF MISO: SPI Master In , Slave Out MOSI: SPI Master Out, Slave In SPI: Serial, Peripheral Interface Figure 12. SPI timing diagram 4.3 Mailbox Usage Commands to the MMA9555L consist of a write followed by one or more reads. It may take some time to complete the command and a flag can be checked to determine if the command has completed. That flag is the Command Complete (COCO) bit, the seventh bit of the read data in the second mailbox. (See Table 16 on page 23.) On a read operation, the COCO bit indicates if the command has been processed. The host processor can determine the status of the command's processing by repeatedly reading or polling the second mailbox until the COCO bit is set. Alternatively, the MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 20 Freescale Semiconductor, Inc. Mailbox Usage MMA9555L can be configured to assert an interrupt signal at the completion of a command. If configured, the INT_O interrupt will be set immediately after the COCO bit has been set. For more information, see "Configuring mailbox operational mode" on page 96. 4.3.1 Mailbox Command Format for a Write Commands written to the MMA9555L are sent in the format shown in the following table. Mailboxes are filled with data, depending on the target application. All commands start with the APP_ID, the command, the destination offset, and the number of data bytes to write. All commands must be written in a single, I2C/SPI transaction starting at Mailbox 0, but the response can be read from any subset of the mailbox registers. For a write-request command, the first four mailboxes must be written with enough bytes to hold the requested number of bytes. The format of the data bytes is specific to the targeted application. (Applications are described in Table 15.) Table 13. Mailbox commands formats Offset 7 6 5 4 0x00 0x01 3 2 1 0 Application ID (APP_ID) 0 Command Byte offset (upper 4 bits) 0x02 Byte offset (lower 8 bits) 0x03 Requested number of bytes to read/write 0x04 Write data 0 0x05 Write data 1 0x06 Write data 2 .... Write data n The following table gives the details of the different parts of the data packet for a Write command. Table 14. Mailbox command format details Block Application ID Description Application targeted for the issued command, see Table 15. Command to be performed: Command Byte offset * * * * 0: Read application fixed bytes (version information) 1: Read application configuration bytes 2: Write application configuration bytes 3: Read application status or output Sets the offset of the first byte to be accessed, counting from the start of the register space. This enables a subset of the registers to be accessed by setting the start location to something other than zero. Requested number Number of bytes requested to be read or written. of bytes Write data The data being written. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 21 Mailbox Usage 4.3.2 Application IDs, names, and descriptions The following table gives the names and IDs of the Freescale applications associated with MMA9555L. Table 15. Application descriptions Application ID Application Name 0x00 Version 0x01 Scheduler 0x02 Reserved 0x03 GPIO-AppMap Description Returns a 12-byte pack with the device identifier number and the version numbers of the ROM, firmware, and hardware. (For more details, see Chapter 5, "Version Application".) Configures the system, applications, and the MMA9555L infrastructure to run at specific sample rates. Additionally, the identifier reads the number of times each task has been executed. Configures the GPIO application to map a specific application output bit to specific GPIO pins. (For more details, see Chapter 7, "GPIO-AppMap Application") The GPIO pins are limited to GPIO6 through 9. Configures an internal mailbox table to map which output bytes from specific application identifiers will be accessible in the Normal mode and the Legacy mode's Quick-Read registers mailboxes. The application identifier can perform a table reset to reinstall the default values when the MMA9555L resets. 0x04 Mailbox 0x05 Reserved 0x06 Analog Front End 0x0C-0x0D Reserved 0x0F Data FIFO 0x10 Event queue 0x11 Status register 0x12 Wake/Sleep 0x13-0x14 Reserved 0x15 Pedometer 0x16 Reserved 0x17 Reset/suspend/clear Controls the Reset/Suspend/Clear functions of the MMA9555L. 0x18 Mailbox mode config Configures different operation modes of the mailbox and provides the status value of the mailbox when Stream mode is running. 0x19 GPIO Input/Output 0x1B-0x1F Reserved 0x20-0xFF Reserved Configures different parameters of the AFE and reads XYZ data from the accelerometer. For further details, see Chapter 9, "Analog Front End Application". Configures parameters of the Data-FIFO application and reads the output bytes from its output structure and the contents of the FIFO buffer. Configures parameters of the Event-queue application and reads the output bytes from its output structure and the contents of the Event-queue buffer. Provides access to the MMA9555L system-status information. Configures the power-control modes of the accelerometer. The application has three modes of operation: Run, Doze, and Sleep. Application that can detect the step count. Controls GPIO2-GPIO8 as input or output pins. Indicates an invalid application index. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 22 Freescale Semiconductor, Inc. Mailbox Usage 4.3.3 Mailbox command format for a read Though all commands must be written in a single I2C/SPI transaction starting at Mailbox 0, the response can be read from any subset of the mailbox registers. When the MMA9555L is configured to stream data (as in FIFO mode), the read commands must be constructed as multiples of 32 bytes in order to trigger the internal transfer of the next set of data to the mailboxes. A read-request command requires a write to the first four mailboxes. The format of the information returned from the MMA9555L is shown in Table 16. Similar to the command format, the response format follows the specific application's format. Mailboxes are filled with data depending on the target application. All responses start with the responding APP_ID, the COCO the ERROR STATUS, the actual data count, and the requested data count. The format of the remaining data bytes is specific to the responding application. Table 16. Mailbox response formats Mailbox 7 6 5 0x00 0x01 4 3 2 1 0 Application ID (APP_ID) COCO Error code 0x02 Actual number of bytes read/written 0x03 Requested number of bytes to read/write 0x04 Read data 0 0x05 Read data 1 0x06 Read data 2 .... Read data n Table 17 describes the details of the different parts and fields of a response message. Table 17. Mailbox response format details Block Application ID (APP_ID) Description The ID of the application that is responding. (See Table 16 on page 23.) COCO Command complete. This bit must be set to 0b when a command is written and is set to 1b by the MMA9555L platform, when the command has been processed. The other registers do not contain valid results until this bit is set. Error code The seven bytes that store the error code of the command. A zero indicates there was no error. (For more information, see Table 18.) Actual number of bytes Actual number of bytes read or written. This block reports back the actual number of bytes that were read or written. It is normally the same as the requested number of bytes, but it will be reduced if the requested number of bytes plus the Byte Offset exceeds the number of bytes in the requested block's data structure. Requested number Number of bytes requested to be read or written. of bytes Read data The data that was read. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 23 Mailbox Usage Table 18 describes the status or error-code results returned in Mailbox 0x01. Table 18. Error-Status codes returned in Mailbox 0x01 Error Code Name 0x00 MCI _ERROR_NONE Command completed with no errors. 0x04 MCI _ERROR_PARAM Incorrect input parameter. Error may be due to an incorrect application ID, an incomplete command, or an incorrect offset. 0x19 MCI _INVALID_COUNT Returned when the command COUNT is greater than the output structure size. 0x1C MCI_ERROR_COMMAND 0x21 0x22 0x23 0x24 Description Returned any time that the command interpreter does not recognize a command code. Returned when the host sends a number of bytes with a wrong payload. MCI_ERROR_INVALID_LENGTH MMA9555L checks any mismatches between the amount of bytes received and the actual payload sent by the host. MCI_ERROR_FIFO_BUSY FIFO is busy performing a push operation and it is not possible to execute any other function. Returned when the host tries to reconfigure the FIFO module. The FIFO application configuration can only be written once. In order to reconfigure MCI_ERROR_FIFO_ALLOCATED the FIFO, the whole device must be reset. This is because the FIFO application requests RAM and RAM can only be allocated once. MCI_ERROR_FIFO_OVERSIZE Returned when the host wants to set a FIFO buffer size out of the memory boundaries within the MMA9555L device. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 24 Freescale Semiconductor, Inc. 5 Version Application The MMA9555L device's system-version information is stored in a 12-byte packet and contains system-identity information including device-hardware ID; the versions of the ROM Application ID bootloader, primary firmware, and hardware; and the system-build information. Table 19 describes the system-version packet and its corresponding mailbox alignment. Default speed Always available. Byte Configuration registers None. Status registers None. Table 19. Version command description bytes Mailbox number Description 0x00 4 Device identifier 31:24 5 Device identifier 24:16 6 Device identifier 15:8 7 Device identifier 7:0 8 ROM major version number 7:0 9 ROM minor version number 7:0 10 Firmware major version number 7:0 11 Firmware minor version number 7:0 12 Hardware major version number 7:0 13 Hardware minor version number 7:0 14 Build major version number 7:0 15 Build minor version number 7:0 Table 20 describes the Build Major and Build Minor version-number fields. Table 20. Version application, Build major and minor bytes Byte 3 4 Address 0x1FD 0x1FC Description Bit fields Build major version number * 7-3 Build's day of the month Range, 1 to 31 * 2-0 Year of build, from 2010 Range, 0 to 7. Build minor version number * 7 -- Release - 1 Engineering version - 0 Production release * 6-4 Build number * 3-0 Month of build Range, 1 to 12 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 25 Reading the version information 5.1 Reading the version information To read the MMA9555L's version information, send the following command packets to the mailboxes: 1. MB0: Set APP_ID to 0x00. 2. MB1: Command to 0x00. Reads version information. 3. MB2: Set offset to zero 0x00. Starts reading at offset 0. 4. MB3: Set count field to 0x0C. Reads12 bytes of data. Bytes to Send: 0x00, 0x00, 0x00, 0x0C. The expected response to these commands is given in the following example. NOTE The current Firmware Build information reflects the framework build and not the pedometer or directional features of the MMA9555L. Example 1. 00 80 0C 0C 2F 33 48 B8 01 01 02 02 01 06 03 41 MB0: APP_ID = 0x00 MB1: STATUS = 0x80 Command Complete, no errors MB2: RequestedData count= 0xC MB3: Actual Data Count= 0xC MB4-7: Device ID = 0x2F3348B8 MB8-9: ROM Version = 01.01 MB10-11: Firmware Version = 02.02 MB12-13: Hardware Version = 01.06 MB14-15: Firmware Build = 03.41 (Production #3, 4 Mar 2011) MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 26 Freescale Semiconductor, Inc. 6 Scheduler Application A simple task scheduler manages execution of the applications of the MMA9555L. Based on a run-to-completion scheme, the scheduler features very low cycle and memory overhead. The scheduler is tightly coupled with the Analog Front End's sampling rate and is triggered at the start of every sample interval. The system is designed such that all applications must complete their processing within the sample interval. The scheduler is used in the defined applications. A priority scheme allows short-duration, high-priority tasks, such as data sampling and filtering, to preempt long-duration, low-priority tasks. The scheduler scans serially through the list of applications, looking for applications that have the same priority as the scheduler's current priority. When there is a priority match, an activity level is checked to determine if the application should be run in the current scheduler's interval. Application ID 0x01 Default speed (Runs all the time.) Configuration registers Start on page 29. Status registers Start on page 36. An application's activity mask can be set to High, Low, Both, or None. This feature allows an application to run during high activity, low activity, both, or not at all. The Sleep/Wake application defines the thresholds of activity between Sleep and Wake, or High and Low activity. Priorities from 16 to 23 are linked directly to the frame execution rate, see Table 21. The lower-priority levels provide a range of values for managing applications in the user system. The scheduler automatically executes all the applications with a priority corresponding to the scheduler's current running priority level. Once the scheduler has identified an application to run, it does a context switch to that application. When the application completes, context is returned to the scheduler and it looks for more applications with the same priority. For additional information, contact Freescale Sensors Applications Engineering. 6.1 Scheduler application elements Each MMA9555L application is assigned an application code, a priority and an activity level. The priority and activity level parameters determine when the scheduler runs the application. 6.1.1 Priority levels A priority scheme allows short-duration, high-priority applications--such as data sampling and filtering--to preempt longduration, low-priority applications. The scheduler supports 24 unique priorities, from 0x00 to 0x17 (0 to 23, in decimal). The larger the number, the higher the priority--higher-numbered applications run before lower-numbered applications. Multiple applications can be assigned the same priority level. The priority level for each application is encoded by the lower six bits in the scheduler_parameters registers. See "Scheduler parameters register" on page 33. Priorities from 0 to 15 (0x00 to 0x0F) can trigger an application when an interrupt occurs. Priorities 16 to 23 (0x10 to 0x17) are linked to the Analog Front End (AFE) execution rate. All applications with a priority of 16 to 23 are automatically software-triggered by the Scheduler. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 27 Scheduler application elements Table 21. Priorities descriptions Priority Level Description 0x17 Applications with this priority run at 488 Hz 0x16 Applications with this priority run at 244 Hz 0x15 Applications with this priority run at 122 Hz 0x14 Applications with this priority run at 61 Hz 0x13 Applications with this priority run at 30 Hz 0x12 Applications with this priority run at 15 Hz 0x11 Applications with this priority run at 7 Hz 0x10 Applications with this priority run at 3 Hz 0x0F Highest user assignable priority level (lower than 3 Hz) 0x0E 0x0D 0x0C 0x0B 0x0A 0x09 0x08 0x07 User-assignable priority levels 0x06 0x05 0x04 0x03 0x02 0x01 0x00 6.1.2 Lowest user assignable priority level Activity levels The MMA9555L uses an activity level attribute to indicate how physically active the device is. The measured physical acceleration and motion actions of the device are classified into two ranges: high activity and low activity. The activity level is used with the priority level to determine which applications run first. Applications can be set to run during these conditions: * Always run * Run during high activity * Run during low activity * Never run MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 28 Freescale Semiconductor, Inc. Interrupts The activity level for each application is encoded in the upper two bits of the scheduler_parameters registers. See "Scheduler parameters register" on page 33. The Sleep/Wake application alone determines the activity level, therefore high/low activity is entirely a function of the sleep/wake threshold parameters. When in run mode, the scheduler only executes applications with the high activity parameter bit set. Similarly, when in doze mode, the scheduler only executes applications with the low activity parameter bit set. Since these bits are separate, an application has the option to set both to run regardless of the activity level. The low activity level parameter is like a filter that skips applications normally run after each AFE sample interval. The idea is that when the sensor is not moving, such as sitting on your desk, you can save power by not running applications, for example portrait landscape. 6.2 Interrupts Interrupts immediately divert execution from any application or the idle state into dedicated interrupt handlers. The scheduler is not invoked, so the interrupt returns without redirection. All interrupt handlers disable interrupts, so application ready, communication, and pin interrupts divert execution only from applications or the idle state. Interrupts are never nested. The MMA9555L supports the interrupts listed in the Table 22. Each supported interrupt can be associated with zero or more priorities. When the interrupt occurs, the scheduler triggers all the applications associated with the priorities configured for that interrupt. The priorities for each interrupt are configured in the scheduler configuration parameter structure. Table 22. Supported interrupts (1) Name SFD 1. Description Start of Digital Frame interrupt. This interrupt occurs when the start of frame signal is asserted. COCO Conversion-complete interrupt. This interrupt occurs when the AFE cycle has completed and all ADC conversions are complete and ready to be used. IRQ IRQ pin interrupt. This interrupt occurs when the selected input pin detects the configured condition (rising edge/high level or falling edge/low level). For more information, see the MMA955xL Intelligent, Motion-Sensing Platform Hardware Reference Manual (MMA955xLHWRM), listed in "Related Documentation" on page 2. Interrupts are assigned to an application in the Interrupt Assignment registers. See "Interrupt assignment registers" on page 32. 6.3 Scheduler configuration registers The scheduler has the following three groups of configuration registers: * request_to_start register * interrupt assignment registers * scheduler parameters registers MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 29 Scheduler configuration registers The configuration and status registers are listed in the following table. Table 23. Scheduler configuration and status registers Register type Configuration Status 1. Address Width (bits) Register Name 0x00-0x03 32 Request_to_start 0x04-0x07 32 SFD Interrupt_AppIDs 0x08-0x0B 32 AFE COCO Interrupt_AppIDs 0x0C-0x0F 32 IRQ Interrupt_AppIDs 0x10-0x13 32 Reserved 0x14-0x17 32 Reserved 0x18-0x1B 32 Reserved 0x1C-0x1F 32 Reserved 0x20-0x23 32 Reserved 0x24-0x27 32 Reserved 0x28-0x2B 32 Reserved 0x2C 8 sched_parms_APP_ID_0x00 0x2D-0x4A 8 each sched_parms_APP_ID_0x01 through 0x1E(1) 0x4B 8 sched_parms_APP_ID_0x1F Address Width (bits) Register Name 0x00-0x03 32 Timeout Status Shaded rows indicate the compressed registers. The request_to_start register is a way to run the applications under scheduler control. The interrupt assignment registers connect applications to interrupt events. The scheduler parameter registers assign activity levels and priorities to the applications. In the event that an application does not complete before it is triggered again, the first instance of the application runs to completion before the second instance starts. If a third trigger occurs before the first instance of the application completes, the application misses an instance and is marked in the timeout register. By checking the timeout_status register, the user can determine which priority application was missed. The corresponding bit of the timeout is set in the timeout_status register. 6.3.1 request_to_start register An application can be scheduled to run by setting the bit corresponding to the application's APP_ID in the request_to_start register. The scheduler manages starting applications, depending on priority and activity. When an application finishes and returns, the scheduler clears the corresponding bit in the request_to_start register. The request_to_start register enables a user to trigger one or more applications via the slave-port command. When modifying this register, the user must logically OR the current value with the new value (with a read/modify/write access) to prevent the erasure of the task waiting to be started. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 30 Freescale Semiconductor, Inc. Scheduler configuration registers Table 24. request_to_start register 0x00(MSB) Offset Bit 7 6 5 4 3 0x01 2 1 0 7 6 5 4 3 2 Field request_to_start [31:24] request_to_start [23:16] Reset 0x00 0x00 Offset 0x02 0x03(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field request_to_start [15:8] request_to_start [7:0] Reset 0x00 0x00 1 0 1 0 Table 25. request_to_start description Field Description Indicates which APP_IDs are marked for starting at the beginning of the next scheduler interval. Each bit corresponds to an APP_ID. It is important that the user do a read/modify/write type of access to ensure that the contents of the resister are logically ORed with the new value to avoid erasing the request_to_start bit of 31:0 the other APP_IDs that are waiting to start. Setting the bit will mark the APP_ID for starting in the next request_to_start scheduler loop. Units: None. Range of valid values: 0 to 0xFFFFFFF. The host controller may issue a command through the slave communications port to trigger the running of an application. To do this, the host controller does a read/modify/write to the request_to_start configuration register and sets the appropriate bit associated with the application that the host wants to start. Regardless of which mechanism triggers the Scheduler application to start--a hardware interrupt, a slave port command, or an internal trap interrupt--it always executes the highest-priority applications first. As a result, a slave-port command could trigger a low-priority application, but some time may occur before that application actually executes. 6.3.2 request_to_start register configuration example To configure the request_to_start register, send this command, read the register and modify it, and write it back. Example 2. 1. 2. 3. 4. MB0: Set the Scheduler application identifier (0x01). MB1: Set the Command: Read Config application identifier (0x10). MB2: Set the Offset to Zero field (0x00) to point to the request_to_start configuration register. MB3: Set the Count field (0x04) to request four bytes. Bytes to send: 0x01, 0x10, 0x00, 0x04. 5. Read back the mailboxes. The current value of the request_to_start register is stored in MB4-MB7. 6. Modify the value as needed: 7. MB0: Set the Scheduler application identifier (0x01). 8. MB1: Set the Command: Write Config application identifier (0x20). 9. MB2: Set the Offset to Zero field (0x00) to point to the request_to_start configuration register. 10. MB3: Set the Count field (0x04) to writing four bytes. 11. MB4: Set the DATA value to 0xAA. 12. MB4: Set the DATA value to 0xBB. 13. MB4: Set the DATA value to 0xCC. 14. MB4: Set the DATA value to 0xDD. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 31 Scheduler configuration registers Bytes to send: 0x01, 0x20, 0x00, 0x04, 0xAA, 0xBB, 0xCC, 0xDD. 6.3.3 Interrupt assignment registers There are 10 possible interrupts in the MMA955xL platform, among these interrupts three are accessible in MMA9555L from the host system. Each interrupt is assigned to an application through the user_interrupt parameter registers. When an interrupt happens, the scheduler handler logically ORs the contents of the user_interrupt register with the request_to_start parameter register. The scheduler runs the appropriate application the next time the application's priority is runable. The scheduler uses the interrupt vector to determine which application-ready interrupt occurred and sets a bit in the request_to_start register. In the bit vector, each bit corresponds to a task and the bit position indicates the priority of the application. The appropriate interrupt is acknowledged to the hardware, usually by clearing a flag bit in the peripheral's memory-mapped status register. In the special case that an AFE, results-ready interrupt occurred, supervisor-only AFE registers are copied into user-mode shadow registers. Table 26. user_interrupt registers 0x04(MSB) Offset Bit 7 6 5 4 3 0x05 2 1 0 7 6 5 4 3 2 Field SFD Interrupt_AppIDs [31:24] SFD Interrupt_AppIDs [23:16] Reset 0x00 0x00 Offset 0x06 0x07(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field SFD Interrupt_AppIDs [15:8] SFD Interrupt_AppIDs [7:0] Reset 0x00 0x00 Offset 0x08(MSB) 0x09 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 1 0 1 0 Field AFE_COCO Interrupt_AppIDs [31:24 AFE_COCO Interrupt_AppIDs [23:16] Reset 0x00 0x00 Offset 0x0A 0x0B(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field AFE_COCO Interrupt_AppIDs [15:8] AFE_COCO Interrupt_AppIDs [7:0] Reset 0x00 0x00 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 32 Freescale Semiconductor, Inc. Scheduler configuration registers Table 26. user_interrupt registers (Continued) 0x0C(MSB) Offset Bit 7 6 5 4 3 0x0D 2 1 0 7 6 5 4 3 2 Field IRQ Interrupt_AppIDs [31:24] IRQ Interrupt_AppIDs [23:16] Reset 0x00 0x00 Offset 0x0E 0x0F(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field IRQ Interrupt_AppIDs [15:8] IRQ Interrupt_AppIDs [7:0] Reset 0x00 0x00 1 0 1 0 Table 27. user_interrupt bit descriptions Field Description Bit vector indicating the tasks that start after the interrupt. Each bit corresponds to a task and the bit position indicates the task's priority. This 32-bit parameter should match the priority of the task that is executing when 31:0 the interrupt occurs. Interrupt_AppIDs Units: None. Range of valid values: 0 to 0xFFFFFF. 6.3.3.1 Interrupt_App_IDs register configuration example In this example, the user has an external interrupt source that wants to run application APP_ID = 0x19. This requires setting the 0x19 bit position in the IRQ_interrupt_APP_IDs register at offset 0x0C-0x0F. Example 3. 1. 2. 3. 4. 5. MB0: Set the Scheduler application identifier (0x01). MB1: Set the "Command: Write Config" application identifier (0x20). MB2: Set the Offset to Zero field (0x0C) to point to the IRQ_interrupt_APP_IDs register. MB3: Set the Count field (0x04) to write four bytes. MB4: Set the DATA value to 0x20. This bit is the 0x19th bit in this 32 bit register. MB4: Set the DATA value to 0x00. MB4: Set the DATA value to 0x00. MB4: Set the DATA value to 0x00. 6. 7. 8. Command to send for write: 0x01, 0x20, 0x0C, 0x04, 0x20, 0x00, 0x00, 0x00. 6.3.4 Scheduler parameters register The sched_parms registers structure is shown in Table 28. For more information on the (Activity) and (Priority) bits, see Table 29 on page 34. Table 28. sched_parms register structure Bit Field 7 6 (Activity) 5 4 3 2 1 0 (Priority) MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 33 Scheduler configuration registers Table 29. sched_parms_APP_ID bit descriptions Field Description Scheduler parameters for each task, this value allows accelerometer activity (motion) to determine whether a task should run. High and low activity thresholds are defined with the Sleep/Wake application. (See Chapter 13, "Sleep/Wake Application".) Units: None. Range of valid values: 7:6 (Activity) * * * * 0x03: ALWAYS 0x02: ACTIVE 0x01: INACTIVE 0x00: NEVER // execute application during high and low activity // execute application only during high activity // execute application only during low activity // never execute application Scheduler parameters for each task, this value determine the priority of the application. Units: None. Range of valid values: 5:0 (Priority) * * * * * * * * * * * * * * 0x17: TASK488HZ 0x16:TASK244HZ 0x15: TASK122HZ 0x14: TASK61HZ 0x13: TASK30HZ 0x12: TASK15HZ 0x11: TASK7HZ 0x10: TASK3HZ 0x0F: PRIORITY15 0x0E: PRIORITY14 0x0D: PRIORITY13 0x0C: PRIORITY12 0x0B: PRIORITY11 0x0A: PRIORITY10 * * * * * * * * * * 9: PRIORITY9 8: PRIORITY8 7: PRIORITY7 6: PRIORITY6 5: PRIORITY5 4: PRIORITY4 3: PRIORITY3 2: PRIORITY2 1: PRIORITY1 0: PRIORITY0 // task running at 488 Hz // task running at 244 Hz // task running at 122 Hz // task running at 61 Hz // task running at 30 Hz // task running at 15 Hz // task running at 7 Hz // task running at 3 Hz The variable data for the sched_parms registers include the register name, offset, and reset. Each of the possible application IDs (0x00-0x1F) is associated with a scheduler parameter register. The following table shows the APP_IDs and their associated register offsets and reset values. Table 30. sched_parms registers' differentiating values Register Resets Offset Name Application Bits 7:6 Bits 5:0 0x2C sched_parms_APP_ID_0x00 Version 0x00 0x00 0x2D sched_parms_APP_ID_0x01 Scheduler 0x00 0x17 0x2E sched_parms_APP_ID_0x02 Communications 0x03 0xD7 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 34 Freescale Semiconductor, Inc. Scheduler configuration registers Table 30. sched_parms registers' differentiating values (Continued) Register Resets Offset Name Application Bits 7:6 Bits 5:0 0x2F sched_parms_APP_ID_0x03 GPIO-AppMap 0x03 0xD7 0x30 sched_parms_APP_ID_0x04 Mailbox 0x03 0x17 0x31 sched_parms_APP_ID_0x05 Reserved -- -- 0x32 sched_parms_APP_ID_0x06 AFE 0x03 0xD7 0x33 sched_parms_APP_ID_0x07 Reserved 0x00 0x00 0x34 sched_parms_APP_ID_0x08 Reserved 0x00 0x00 0x35 sched_parms_APP_ID_0x09 Reserved 0x00 0x00 0x36 sched_parms_APP_ID_0x0A Reserved 0x00 0x00 0x37 sched_parms_APP_ID_0x0B Reserved 0x00 0x00 0x38 sched_parms_APP_ID_0x0C Reserved 0x00 0x00 0x39 sched_parms_APP_ID_0x0D Reserved 0x00 0x00 0x3A sched_parms_APP_ID_0x0E Reserved 0x00 0x00 0x3B sched_parms_APP_ID_0x0F Data FIFO 0x03 0xD7 0x3C sched_parms_APP_ID_0x10 Event Queue 0x03 0xD7 0x3D sched_parms_APP_ID_0x11 Status Register 0x03 0xD7 0x3E sched_parms_APP_ID_0x12 Wake/Sleep 0x03 0xD7 0x3F sched_parms_APP_ID_0x13 Reserved 0x00 0x00 0x40 sched_parms_APP_ID_0x14 Reserved 0x00 0x00 0x41 sched_parms_APP_ID_0x15 Reserved 0x00 0x00 0x42 sched_parms_APP_ID_0x16 Reserved 0x00 0x00 0x43 sched_parms_APP_ID_0x17 Reset/Suspend/Clear 0x03 0xD7 0x44 sched_parms_APP_ID_0x18 Mailbox Configuration 0x00 0x00 0x45 sched_parms_APP_ID_0x19 GPIO Input/Output 0x00 0x00 0x46 sched_parms_APP_ID_0x1A 6 Directions Detection 0x00 0x00 0x47 sched_parms_APP_ID_0x1B Reserved 0x00 0x00 0x48 sched_parms_APP_ID_0x1C Reserved 0x00 0x00 0x49 sched_parms_APP_ID_0x1D Reserved 0x00 0x00 0x4A sched_parms_APP_ID_0x1E Reserved 0x00 0x00 0x4B sched_parms_APP_ID_0x1F Reserved 0x00 0x00 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 35 Scheduler status registers 6.4 Scheduler status registers The scheduler applications contain a set of output or status registers. Status registers can be read by a host processor, through the I2C/SPI slave-port read-data commands, or by internal applications, through direct reads. The scheduler status is a 32-bit register that gives the priority levels for applications that have timed out. Applications time out when their priority level is the one that is currently running and they have been marked with request_to_start. Such an application has not finished running before it needs to start again. 6.4.1 Timeouts A timeout condition indicates that the scheduler has been compromised by an application. Table 31. Scheduler status register 0x00(MSB) Offset Bit 7 6 5 4 3 0x01 2 1 0 7 6 5 4 3 2 Field timeout_status[31:24] timeout_status[23:16] Reset 0x00 0x00 Offset 0x02 0x03(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field timeout_status[16:8] timeout_status[7:0] Reset 0x00 0x00 1 0 1 0 Table 32. sched_parms_APP_ID bit descriptions Field Description 31:0 timeout_status Indicates the priority level of the task that has timed out, one or more times. The register sets the corresponding priority-level bit when a task is timed out (currently running and being marked request_to_start). This bit must be monitored to verify that no user task is compromising the scheduler execution. Units: None. Range of valid values: 0 to 0xFFFFFFFF. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 36 Freescale Semiconductor, Inc. 7 GPIO-AppMap Application 7.1 Overview of GPIO-AppMap application The GPIO-AppMap application assigns a bit from an application's status register to a specific GPIO pin. The configuration registers contain the application ID and the bit number of the output byte for each GPIO pin. Application ID 0x03 Default speed Configuration The GPIO-AppMap application connects the MMA955xL platform's GPIO pins to status bits registers in an application's status registers. The GPIO-AppMap application can control four physical GPIO pins. Each of the four GPIO pins (GPIO6, 7, 8, and 9) has an associated APP_ID Status register and an SR_bit register. registers The GPIO-AppMap application also has a general polarity register where the GPIO pins can be set to be active high or active low. The default or start-up condition of the GPIO pins are unassigned. 30 Hz. Start on page 37. None. The GPIO pins that can be mapped are described in Table 33. Table 33. GPIO pin names, numbers and functions 7.2 Name Pin number GPIO6 12 GPIO7 13 GPIO8 15 GPIO9 2 GPIO configuration registers The GPIO-AppMap application's configurations registers consist of 10 eight-bit registers. This includes two registers for each of the four GPIO pins and two registers for setting the polarity of the GPIO pin. Each GPIO pin is assigned to an APP_ID and as an output bit from the assigned application. The following table gives the bit descriptions for the GPIO-AppMap application's registers. The application's registers are shown in Table 35 through Table 43. The bit descriptions are given in Table 45 on page 40. 7.2.1 GPIO register tables Table 34. APP_ID GPIO6 register 0x00 Offset Bit 7 6 5 4 3 Field APP_ID GPIO6 Reset 0xFF 2 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 37 GPIO configuration registers Table 35. SR_bitnum GPIO6 register 0x01 Offset Bit 7 6 5 4 3 Field SR_bitnum GPIO6 Reset 0x00 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 2 1 0 Table 36. APP_ID GPIO7 register 0x02 Offset Bit 7 6 5 4 3 Field APP_ID GPIO7 Reset 0xFF Table 37. SR_bitnum GPIO7 register 0x03 Offset Bit 7 6 5 4 3 Field SR_bitnum GPIO7 Reset 0x00 Table 38. APP_ID GPIO8 register 0x04 Offset Bit 7 6 5 4 3 Field APP_ID GPIO8 Reset 0xFF Table 39. SR_bitnum GPIO8 register 0x05 Offset Bit 7 6 5 4 3 Field SR_bitnum GPIO8 Reset 0x00 Table 40. APP_ID GPIO9 register 0x06 Offset Bit 7 6 5 4 3 Field APP_ID GPIO9 Reset 0xFF MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 38 Freescale Semiconductor, Inc. GPIO configuration registers Table 41. SR_bitnum GPIO9 register 0x07 Offset Bit 7 6 5 4 3 Field SR_bitnum GPIO9 Reset 0x00 2 1 0 2 1 0 Table 42. GPIO_pol MSB register 0x08(MSB) Offset Bit 7 6 5 4 3 Field Reserved GPIO9 GPIO8 Reset 0x00 0 0 1 0 Table 43. GPIO_pol LSB register 0x09(LSB) Offset Bit 7 6 Field GPIO7 GPIO6 Reserved Reset 0 0 0x00 7.2.2 5 4 3 2 GPIO polarity configuration Table 44. GPIO output, depending on polarity configuration and bit value Input Bits Output Bit GPIO_POLARITY SR_bit x VAL GPIO x 0 0 0 0 1 1 1 0 1 1 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 39 GPIO configuration registers 7.2.3 GPIO application bit descriptions Table 45. GPIO application bit descriptions Field Description 7:0 APP_ID GPIOx The application identifier (APP_ID) of the application assigned to the GPIO pin. A value of 0xFF indicates there is no application assigned. After a reset, no application output bits are mapped to a GPIO. Units: None. Range of valid values: [0:31] and 0xFF. The bit number of the application status registers being assigned to the GPIO pin. 7:0 The bit number depends of the amount of output bytes and the position of the bit in the register. SR_bitnum GPIOx Units: None. Range of valid values: [0:255] GPIO_polx Reserved Defines the output polarity of the GPIO pin designated by the n variable in the field name. This register uses negative logic 0 to configure active high and 1 for active low. Table 34 on page 37 indicates which pin of the register corresponds to each GPIO. Units: None. Range of valid values: 0: Output is active high (output bit = high high on GPIO pin). 1: Output is active low (output bit = high low on GPIO pin). Indicates that the bit is reserved. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 40 Freescale Semiconductor, Inc. 8 8.1 Mailbox Application Application ID Overview of Mailbox application The Mailbox (MBOX) application gathers output data from other applications and puts that data into the mailbox registers. This enables users to customize and group up to 28 applications' specific data bytes for quick reads. 0x04 Default speed 30 Hz. Configuration Normally, the host may need to read the status and output data from many applications. This registers requires multiple, serial-slave-port transactions. Using the mailbox application enables the 2C or SPI transaction. host to read all necessary data in one serial, I Status The MBOX application provides a shortcut for the user to read different pieces of data from registers different applications by combining the data for reading in one I2C or SPI read transaction. Start on page 41. None. The MBOX application is different than the hardware mailboxes used by the Communication Interface application. The MBOX application combines selected data bytes from specific applications and loads them into the Communications Interface mailboxes. In order to properly configure the system Communications Interface, the MBOX Configuration and Mailbox applications also must be properly configured. The MBOX Configuration application controls how the mailboxes behave and the Mailbox application controls what is placed in the mailboxes. 8.2 Mailbox configuration registers The Mailbox application's registers are described in the following table. The registers' bit descriptions are given in "MBOX bit descriptions" on page 45. Each response mailbox (MB4 to MB31) has two associated configuration registers: APP_ID register and Byte_ID register. When the Mailbox application runs, it copies the data at the Byte_ID from the specified APP_ID and puts that value in the associated mailbox. Users can configure mailboxes 4 through 31. Mailboxes 20 through 31 have a special function in Legacy mode. They are updated automatically in the Legacy/Quick-Read mode. Table 46. MBOX registers 0x00 Offset Bit 7 6 5 4 0x01 3 2 1 0 7 6 5 4 3 Field APP_ID MBOX_4 Byte_ID MBOX_4 Reset 0x00 0x00 Offset 0x02 0x03 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 Field APP_ID MBOX_5 Byte_ID MBOX_5 Reset 0x00 0x00 Offset 0x04 0x05 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 Field APP_ID MBOX_6 Byte_ID MBOX_6 Reset 0x00 0x00 2 1 0 2 1 0 2 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 41 Mailbox configuration registers Table 46. MBOX registers (Continued) 0x06 Offset Bit 7 6 5 4 0x07 3 2 1 0 7 6 5 4 3 Field APP_ID MBOX_7 Byte_ID MBOX_7 Reset 0x00 0x00 Offset 0x08 0x09 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 Field APP_ID MBOX_8 Byte_ID MBOX_8 Reset 0x00 0x00 Offset 0x0A 0x0B Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 Field APP_ID MBOX_9 Byte_ID MBOX_9 Reset 0x00 0x00 Offset 0x0C 0x0D Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 2 1 0 2 1 0 2 1 0 1 0 1 0 1 0 1 0 Field APP_ID MBOX_10 Byte_ID MBOX_10 Reset 0x00 0x00 Offset 0x0E 0x0F Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_11 Byte_ID MBOX_11 Reset 0x00 0x00 Offset 0x10 0x11 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_12 Byte_ID MBOX_12 Reset 0x00 0x00 Offset 0x12 0x13 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_13 Byte_ID MBOX_13 Reset 0x00 0x00 Offset 0x14 0x15 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_14 Byte_ID MBOX_14 Reset 0x00 0x00 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 42 Freescale Semiconductor, Inc. Mailbox configuration registers Table 46. MBOX registers (Continued) 0x16 Offset Bit 7 6 5 4 0x17 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_15 Byte_ID MBOX_15 Reset 0x00 0x00 Offset 0x18 0x19 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_16 Byte_ID MBOX_16 Reset 0x00 0x00 Offset 0x1A 0x1B Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_17 Byte_ID MBOX_17 Reset 0x00 0x00 Offset 0x1C 0x1D Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_18 Byte_ID MBOX_18 Reset 0x00 0x00 Offset 0x1E 0x1F Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_19 Byte_ID MBOX_19 Reset 0x00 0x00 Offset 0x20 0x21 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_20 Byte_ID MBOX_20 Reset 0x11 (Defaults to Status Register application) 0x00 (Status application - MSB) Offset 0x22 0x23 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_21 Byte_ID MBOX_21 Reset 0x11 (Defaults to Status Register application) 0x01 (Status application - LSB) Offset 0x24 0x25 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_22 Byte_ID MBOX_22 Reset 0x10 (Defaults to Event Queue application) 0x03 (Event Queue Status) 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 43 Mailbox configuration registers Table 46. MBOX registers (Continued) 0x26 Offset Bit 7 6 5 4 0x27 3 2 1 0 7 6 5 4 3 2 Field APP_ID MBOX_23 Byte_ID MBOX_23 Reset 0x0F (Defaults to Data FIFO application) 0x03 (FIFO status) Offset 0x28 0x29 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 1 0 Field APP_ID MBOX_24 Byte_ID MBOX_24 Reset 0x06 (Defaults to Analog Front End application) 0x28 (Analog Front End Frame Counter - MSB) Offset 0x2A 0x2B Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 Field APP_ID MBOX_25 Byte_ID MBOX_25 Reset 0x06 (Defaults to Analog Front End application) 0x29 (Analog Front End Frame Counter - LSB) Offset 0x2C 0x2D Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field APP_ID MBOX_26 Byte_ID MBOX_26 Reset 0x06 (Defaults to Analog Front End application) 0x00 Analog Front End Stage 0 - X MSB Offset 0x2E 0x2F Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field APP_ID MBOX_27 Byte_ID MBOX_27 Reset 0x06 (Defaults to Analog Front End application) 0x01 (Analog Front End Stage 0 - X LSB) Offset 0x30 0x31 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field APP_ID MBOX_28 Byte_ID MBOX_28 Reset 0x06 (Defaults to Analog Front End application) 0x02 (Analog Front End Stage 0 - Y MSB) Offset 0x32 0x33 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field APP_ID MBOX_29 Byte_ID MBOX_29 Reset 0x04 (Analog Front End Stage 0 - Z MSB) 0x03 (Analog Front End Stage 0 - Y LSB) Offset 0x34 0x35 Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field APP_ID MBOX_30 Byte_ID MBOX_30 Reset 0x06 (Defaults to Analog Front End application) 0x04 (Analog Front End Stage 0 - Z MSB) 0 0 0 0 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 44 Freescale Semiconductor, Inc. Mailbox configuration registers Table 46. MBOX registers (Continued) 0x36 Offset 7 Bit 6 5 4 0x37 3 2 1 0 7 6 5 4 3 2 1 Field APP_ID MBOX_31 Byte_ID MBOX_31 Reset 0x06 (Defaults to Analog Front End application) 0x05 (Analog Front End Stage 0 - Z LSB) 8.2.1 0 MBOX bit descriptions Table 47. MBOX bit descriptions Field Description 7:0 APP_ID MBOX_x Specifies the application to provide the output byte, using the application identifier. Units: None. Range of valid values: 1 to 31. Values outside this range or values for a nonexistent application may cause unexpected system behavior. 7:0 Byte_ID MBOX_x Indicates the byte number of the application's status or output registers that are being sent to this mailbox. The most-significant byte for a specific application's output is identified as Byte 0 and the least-significant byte is Byte x. Units: Nondimensional. Range of valid values: 0 to 255. 8.2.2 Configuring XYZ data The MBOX application aggregates application data and presents it in the mailboxes. The AFE application (APP_ID 0x06) provides the XYZ accelerometer data with output registers 0 through 5 containing the FRONTEND_Stage_0 XYZ data. The following example shows what a host would send to the MMA9555L device to create the configuration to set up quick-read mailboxes 4-9 to contain the following, FRONTEND_Stage_0_XYZ data: * Data X to mailboxes 4 and 5 * Data Y to mailboxes 6 and 7 * Data Z to mailboxes 8 and 9 Example 4. MBOX0 = 0x04 MBOX1 = 0x20 MBOX2 = 0x00 MBOX3 = 0x0C MBOX4 = 0x06 MBOX5 = 0x00 MBOX6 = 0x06 MBOX7 = 0x01 MBOX8 = 0x06 MBOX9 = 0x02 MBOX10 = 0x06 MBOX11 = 0x03 MBOX12 = 0x06 MBOX13 = 0x04 MBOX14 = 0x06 MBOX15 = 0x05 /* /* /* /* /* /* /* /* /* /* /* /* /* /* /* /* Host communicating to MBOX Application */ CONFIG_W command */ Starting at Offset 0 which is the config for MB4 */ Number of bytes to write 12 bytes */ APP_ID_MBOX4 0x06 - AFE APP_ID = 0x06 */ Byte_ID_MBOX4 Data - X MSB */ APP_ID_MBOX5 */ Byte_ID_MBOX5 Data - X LSB */ APP_ID_MBOX6 */ Byte_ID_MBOX6 Data - Y MSB */ APP_ID_MBOX7 */ Byte_ID_MBOX7 Data - Y LSB */ APP_ID_MBOX8 */ Byte_ID_MBOX8 Data - Z MSB */ APP_ID_MBOX9 */ Byte_ID_MBOX9 Data Z - LSB */ MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 45 Mailbox status registers 8.3 Mailbox status registers There are no status registers for this application. 8.4 Reading aggregated data (Legacy mode--Quick read) Once the MBOX application is configured and the device is set to Legacy communication mode, the aggregated data can be read. Assuming that the MBOX application was set up as shown in Section 8.2.2, "Configuring XYZ data", the X, Y, and Z acceleration data output will be available in mailboxes 4 through 9, through the normal command/response Communications Interface. If the host needs to just read the data without the finer control of the command/response model, the MMA9555L can be put into Legacy mode. This assigns the desired data to registers in the Quick-Read section of the Mailbox registers (MB20-MB31). In Legacy mode, the lower mailbox registers continue to operate in the command/response mode and the upper registers operate in the Quick-Read mode. The data in the Quick-Read registers is automatically updated, so a read-request command is not required before reading the data form the upper mailboxes. The following examples show how to wake up the device, configure it for quick-reading the low-passed-filtered XYZ data, enable the Legacy mode, and read the data. The MMA9555L platform comes out of reset in the Low-Power or Sleep mode. In order to start the AFE application and start collecting samples, the MMA9555L must be brought out of Sleep mode and into Run mode This example shows how to disable Sleep mode and enable Wake mode. Example 5. MBOX0 MBOX1 MBOX2 MBOX3 MBOX4 = = = = = 0x12 0x20 0x06 0x01 0x00 /* /* /* /* /* Host communicating to Sleep/Wake Application */ CONFIG_Write command */ Starting at Offset 0x6 */ Number of bytes to write 1 byte */ Write 0x00 which wakes up the device */ Bytes to Send: 0x12, 0x20, 0x06, 0x01, 0x00 The AFE application (APP_ID 0x06) provides the XYZ accelerometer data with output registers 0 through 5 containing the FRONTEND_Stage_0 XYZ data. By default, the Quick-Read registers (MB26-MB31) are assigned 0x00 Analog Front End Stage 0 - X MSB. The AFE application, however, provides XYZ, low-pass-filtered data in registers 0x18 through 0x1D (FRONTEND_488_100_LPF). To quickly read this data, the Quick-Read mailbox registers would have to be configured so that they are populated with the low-passed-filtered, XYZ data. The following example shows how a host would direct the MMA9555L device to set up quick-read mailboxes to contain the following, FRONTEND_488_100_LPG XYZ data: * Data X to mailboxes 26 and 27 * Data Y to mailboxes 28 and 29 * Data Z to mailboxes 30 and 31 Example 6. MBOX0 = 0x04 /* Host communicating to MBOX Application */ MBOX1 = 0x20 /* CONFIG_W command */ MBOX2 = 0x2C /* Starting at Offset 0x2C, the configuration starting point for MB26 */ MBOX3 = 0x0C /* Number of bytes to write 12 bytes */ MBOX4 = 0x06 /* APP_ID_MBOX26 = 0x06 - AFE APP_ID = 0x06 */ MBOX5 = 0x18 /* Byte_ID_MBOX26 = 0x18 - LPF Data starts at register 0x18 - X MSB */ MBOX6 = 0x06 /* APP_ID_MBOX27 */ MBOX7 = 0x19 /* Byte_ID_MBOX27 Data - X LSB */ MBOX8 = 0x06 /* APP_ID_MBOX28 */ MBOX9 = 0x1A /* Byte_ID_MBOX28 Data - Y MSB */ MBOX10 = 0x06 /* APP_ID_MBOX29 */ MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 46 Freescale Semiconductor, Inc. Reading aggregated data (Legacy mode--Quick read) MBOX11 MBOX12 MBOX13 MBOX14 MBOX15 = = = = = 0x1B 0x06 0x1C 0x06 0x1D /* /* /* /* /* Byte_ID_MBOX29 Data - Y LSB */ APP_ID_MBOX30 */ Byte_ID_MBOX30 Data - Z MSB */ APP_ID_MBOX31 */ Byte_ID_MBOX31 Data Z - LSB */ Bytes to send: 0x04, 0x20, 0x2C, 0x0C, 0x06, 0x18, 0x06, 0x19, 0x06, 0x1A, 0x06, 0x1B, 0x06, 0x1C, 0x06, 0x1D. The host then must configure the Mailbox application to operate in Legacy mode, as shown in the following example. Example 7. 1. MB0 = 0x18. Sets the "APP_ID: Mailbox Mode Config" application identifier (0x18). 2. MB1 = 0x20. Sets the "Command: Write Config" (0x20). 3. MB2 = 0x00. Sets the Offset to Zero field (0x00) to point to the configuration register. 4. MB3 = 0x01. Sets the Count field to 0x01 because only one data byte needs to be sent. 5. MB4 = 0x10. Sets the DATA value to 0x10, which sets the LEGACY field to 1b or Legacy mode. Bytes to send: 0x18, 0x20, 0x00, 0x01, 0x10. The MMA9555L platform now is set to Legacy mode and the Quick-Read registers are being constantly updated with the lowpass-filtered, AFE data. All that remains is the issuing of a command to read the six bytes starting at MB26, which contains the XYZ data in constant-read mode. In the following example, "0x__ " represents the data that is sent back to the host. Example 8. MBOX0 MBOX1 MBOX2 MBOX3 MBOX4 MBOX5 MBOX6 MBOX7 MBOX8 MBOX9 = = = = = = = = = = 0x04 0x30 0x1A 0x06 0x__ 0x__ 0x__ 0x__ 0x__ 0x__ /* /* /* /* /* /* /* /* /* /* Host communicating to MBOX Application */ Read Output Data command */ Starting at Offset 0x1A, the hexadecimal offset for mailbox 26 */ Number of bytes to read 6 bytes two bytes each for X, Y, andZ*/ MSB - X */ LSB - X */ MSB - Y */ LSB - Y */ MSB - Z */ LSB - Z*/ Bytes to send: 0x04, 0x30, 0x1A, 0x06, 0x__ , 0x__ , 0x__ , 0x__ , 0x__ , 0x__ . MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 47 9 Analog Front End Application 9.1 Application ID Overview of Analog Front End application 0x06 The Analog Front End application (AFE) samples raw accelerometer data from the analogto-digital converter (ADC) at the execution rate of the application, applies factory and user Default speed trim-correction terms, and filters data to several configurable bandwidths. Configuration For the proper operation of the Pedometer, it is recommended that any change to any of the registers configuration registers of the AFE Application be avoided unless the outcome is well understood. Status registers 30 Hz. Start on page 52. Start on page 56. Outputs Analog Front End Raw 488/100 Hz Sample rate 4 ADC data 3 Offset correction Scale correction Anti-aliasing filter Normalized 488/100 Hz Normalize 1:2 Anti-aliasing filter ABS Absolute value 488/100 Hz Configurable, low-pass filter Normalized 488 Hz/Low-pass filter Configurable, high-pass filter Normalized 488 Hz/High-pass filter Temperature output Configurable, low-pass filter Normalized 244/50 Hz External input conversion Temperature External Figure 13. Front-end signal processing 9.1.1 Sample rate The rate at which the ADC samples the accelerometer data is defined by the sfd_rate register, which is offset 0x0C in the configuration registers of this application. The sample rate can be changed from 488 Hz to 3.81 Hz by setting the appropriate value in the sfd_rate register. For more details, see Table 59 and Table 60 on page 55. NOTE Although the sample rate can be changed in the hardware, it is recommended that the 30 Hz sample rate not be changed, because the Pedometer application requires 30 Hz and the MMA9555L runs at 30 Hz after MMA9555L startup. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 48 Overview of Analog Front End application 9.1.2 Offset and scale correction The AFE's offset and scale correction stages of the signal chain applies trim offset and scaling correction factors which were measured at factory calibration and stored inside each device. Since user offsets are defined at 8-g resolution, those offsets are shifted according to the g mode. User offsets are used to calibrate and compensate for the physical mounting of the part inside the final product. After board mount and assembly, the final test process may include a test to fine tune and compensate the accelerometer orientation. 9.1.3 Anti-aliasing filter After trim correction, the front end uses a sixth-order Chebyshev filter, running up to 488 Hz, to limit the signal bandwidth to 100 Hz. Figure 14. Frequency response of Analog Front End anti-aliasing filter The bandwidth of the anti-aliasing filter depends on the sample rate at which the front end application is running. The following table shows the variation of the filter bandwidth according to the sample rate. Table 48. Anti-aliasing filter bandwidth for different sample rates Stage-0 anti-aliasing Filter Stage-1 anti-aliasing Filter Bandwidth (Hz) Bandwidth (Hz) 488.28 100 50 244.17 50 25 122.07 25 12.5 61.04 12.5 6.25 31.52 6.25 3.125 15.26 3.125 1.562 7.63 1.562 0.781 3.81 0.781 0.390 Sample rate MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 49 Overview of Analog Front End application 9.1.4 Raw data The output of the sensor is a 16-bit, signed value. The sensor always uses all the bits for high accuracy. Depending on the range setting (2-, 4-, or 8-g mode), the output value per g changes. The following table shows the full scale value at the different g ranges, as well as the value of a measured 1-g acceleration at the different g ranges. Table 49.Raw accelerometer output, according to g mode 9.1.5 Range Full scale One-g acceleration +2g + 32 K 16 K +4g + 32 K 8K +8g + 32 K 4K Normalization The filtered data is shifted according to the g mode to normalize the resolution to the 8-g range. The normalized data allows for common handling of the data in the other applications. Data is normalized so that 1-g force acceleration shows output of 0x1000 counts or 4096 decimal counts. 9.1.6 Down-sampling and stage-1, anti-aliasing filter The output of the normalizer is down-sampled by two to generate data sampled at half of the original sample rate. At 488 Hz, the previous, sixth-order Chebyshev filter is applied to down-sampled (244 Hz) data, to create a 50-Hz bandwidth data stream. Table 60 on page 55 provides more details about the varying of the bandwidth, depending of the sample rate of the front-end application. 9.1.7 Absolute value The absolute value of the sensor output is computed. 9.1.8 Configurable, low-pass and high-pass filters First-order, low-pass and high-pass filters--with separate configurable cutoff frequencies at -3 dB--are provided. Eqn. 1 Eqn. 2 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 50 Freescale Semiconductor, Inc. Overview of Analog Front End application Figure 15. Frequency response of configurable, high- and low-pass filters The two following tables contain the cutoff frequency of the filters, varying with the value of K and the sample rate at which the front-end application is executed. Table 50. Cut-off frequency as a function of K and the sample rate for low-pass filter LPF cut-off frequency (Hz) K Sample rate Sample rate Sample rate Sample rate Sample rate Sample rate Sample rate Sample rate = 488.28 = 244.14 = 122.07 = 61.04 = 30.52 = 15.26 = 7.63 = 3.81 1 56.13 28.07 14.03 7.02 3.51 1.75 0.88 0.4385 2 22.50 11.25 5.62 2.81 1.40 0.70 0.3516 0.1758 3 10.39 5.19 2.60 1.30 0.65 0.32 0.1623 0.0811 4 5.014 2.51 1.25 0.63 0.31 0.16 0.0783 0.0392 5 2.47 1.23 0.62 0.31 0.15 0.08 0.0385 0.0193 6 1.22 0.6116 0.31 0.15 0.08 0.04 0.0191 0.0096 7 0.61 0.30 0.15 0.08 0.04 0.02 0.0095 0.0048 8 0.30 0.15 0.08 0.04 0.02 0.01 0.0048 0.0024 9 0.15 0.076 0.04 0.02 0.01 0.0047 0.0024 0.0012 10 0.0759 0.038 0.019 0.0095 0.0047 0.0024 0.0012 0.0006 11 0.0379 0.019 0.0095 0.0047 0.0024 0.0012 0.0006 0.0003 12 0.019 0.0095 0.0048 0.0024 0.0012 0.0006 0.0003 0.0001 13 0.0095 0.0048 0.0024 0.0012 0.0006 0.0003 0.0001 0.00007 14 0.0047 0.0024 0.0012 0.0006 0.0003 0.0001 0.0007 0.00004 15 0.0024 0.0012 0.0006 0.0003 0.0002 0.00008 0.00004 0.00002 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 51 AFE configuration registers Table 51. Cut-off frequency as a function of K and the sample rate for high-pass filter HPF cut-off frequency (Hz) K Sample rate = Sample rate = Sample rate = Sample rate Sample rate Sample rate Sample rate Sample rate = 488.28 244.14 122.07 = 61.04 = 30.52 = 15.26 = 7.63 3.81 1 31.932 15.966 7.9831 3.9915 1.9958 0.9979 0.4989 0.2495 2 17.405 8.7023 4.3511 2.1756 1.0878 0.5439 0.2719 0.136 3 9.1573 4.5787 2.2893 1.1447 0.5723 0.2862 0.1431 0.0715 4 4.7092 2.3546 1.1773 0.5887 0.2943 0.1472 0.0736 0.0368 5 2.3912 1.1956 0.5978 0.2989 0.1495 0.0747 0.0374 0.0187 6 1.2054 0.6027 0.3014 0.1507 0.0753 0.0377 0.0188 0.0094 7 0.6051 0.3026 0.1513 0.0756 0.0378 0.0189 0.0095 0.0047 8 0.3026 0.1513 0.0757 0.0378 0.0189 0.0095 0.0047 0.0024 9 0.1513 0.0757 0.0378 0.0189 0.0095 0.0047 0.0024 0.0012 10 0.0756 0.0378 0.0189 0.0095 0.0047 0.0024 0.0012 0.0006 11 0.039 0.0195 0.0098 0.0049 0.0024 0.0012 0.0006 0.0003 12 0.0195 0.0098 0.0049 0.0024 0.0012 0.0006 0.0003 0.0002 13 0.0098 0.0049 0.0025 0.0012 0.0006 0.0003 0.0002 8E-05 14 0.0049 0.0025 0.0012 0.0006 0.0003 0.0002 8E-05 4E-05 15 0.0024 0.0012 0.0006 0.0003 0.0002 8E-05 4E-05 2E-05 9.2 9.2.1 AFE configuration registers afe_csr Table 52. afe_csr registers 0x00(MSB) Offset Bit 7 6 5 4 0x01(LSB) 3 2 1 0 7 6 5 4 3 Field FS Ext ADC Temp CM Reserved Reserved Reset 0x00 0 0 0x00 0x00 0x00 2 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 52 Freescale Semiconductor, Inc. AFE configuration registers Table 53. afe_csr bit descriptions Field Description 7:6 FS Full-scale selection. AFE_CSR[FS] and AFE_BIAS[SC_AAF_EN] are combined to control AFE gain and trim mode. Units: None. Range of values: Full-scale data range XYZ acceleration scaling (mg/LSB) 00: 8 g 0.244 01: 2 g 0.061 10: 4 g 0.122 11: 8 g 0.244 Specifies whether an external input will or will not be measured during the next analog acquisition phase. Note: The ExtADC and Temp bits must not be set at the same time. Units: None. 5 Ext ADC * 0: No external input is measured during the next analog acquisition phase. * 1: Enables the four AFE channels to measure the external analog input during the next analog acquisition phase. Specifies whether the temperature sensor output will or will not be measured during the next analog acquisition phase. Note: The ExtADC and Temp bits must not be set at the same time. Units: None. Temperature will change slowly so it can be measured with a very low sample rate (1 Hz or less) by occasionally replacing an external ADC measurement with the Temperature ADC measurement. Range of valid values: For valid values for FS and CM parameters, see the Intelligent, Motion-Sensing Platform Hardware Reference Manual (MMA955xLHWRM), listed in "Related Documentation" on page 2 Accelerometer Reference Manual (MMA955xLRM). 4 Temp * 0: No temperature sensor output will be measured during the next analog acquisition phase. * 1: The temperature sensor output will be measured during the next analog acquisition phase. Conversion Mode. Controls the ADC resolution/accuracy versus power and conversion time trade-offs. Units: None 3:2 CM * * * * Reserved 9.2.2 00: Conversion complete in 32 cycles 01: Conversion complete in 16 cycle 10: Conversion complete in eight cycles 11: Conversion complete in four cycles Bit field reserved. user_offset [XYZ] Often, during the mounting process, the accelerometer sensor is not mounted perfectly flat to the board and might also be rotated slightly. This register enables a user to make an after-manufacturing calibration correction. Table 54. user_offset [XYZ] registers 0x02(MSB) Offset Bit 7 6 5 4 3 0x03(LSB) 2 1 0 7 6 5 4 3 Field user_offset[X] user_offset[X][ Reset 0xFF 0xFF Offset 0x04(MSB) 0x05(LSB) Bit 7 6 Field 5 4 3 user_offset[Y] 2 1 0 7 6 5 4 3 2 1 0 2 1 0 user_offset[Y] MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 53 AFE configuration registers Table 54. user_offset [XYZ] registers (Continued) Reset 0xFF 0xFF Offset 0x06(MSB) 0x07(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 Field user_offset[Z] user_offset[Z] Reset 0xFF 0xFF 2 1 0 Table 55. user_offset [XYZ] bit descriptions Field Description 7:0 user_offset[XYZ] Sets user offsets in the X, Y, and Z axes for the accelerometer, depending on the position on the device in the user board. These values are considered as post-mount offsets. Units: 0.244 mg/LSB. Range of valid values: -32,768 to 32,767. Reset value: 0xFF which is interpreted as -1. 9.2.3 config_k This register's bits are shown in the following table. Table 56. config_k registers 0x08 Offset Bit 7 6 5 4 0x09 3 2 1 0 7 6 5 4 3 2 Field config_k[HIGHPASS] config_k[LOWPASS] Reset 0x00 0x00 Offset 0x0A 0x0B Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 Field config_k[TEMP_LPF] config_k[EIC_LPF] Reset 0x00 0x00 2 1 0 1 0 Table 57. config_k bit descriptions Field Description 7:0 config_k[HIGHPASS] High-pass filter configurable cutoff. Units: None. Range of valid values: 0 to 15. 7:0 config_k[LOWPASS] Low-pass filter configurable cutoff. Units: None. Range of valid values: 0 to 15. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 54 Freescale Semiconductor, Inc. AFE configuration registers Table 57. config_k bit descriptions Field Description Low-pass filter, configurable cutoff for temperature sensor output. Units: None. Range of valid values: 0 to 15. 7:0 config_k[TEMP_LPF] Low-pass filter, configurable cutoff for external input conversion output. Units: None. Range of valid values: 0 to 15. 7:0 config_k[EIC_LPF] 9.2.4 sfd_rate This register's bits are shown in the following table. The system defaults to 30 Hz; therefore, this document assumes that 30 Hz is the rate being run. If the user slows down the rate by changing the sfd_rate register, all references to the system frame rate scale accordingly. Table 58. sfd_rate register 0x0C Offset Bit 7 6 5 4 2 1 0 0 1 1 1 sfd_rate Field Reset 3 0 0 0 0 Table 59. sfd_rate bit description Field 7:0 sfd_rate Description Defines the system frame interval, the time period for each sample or the system sample rate in Hz. Units: None. Range of valid values: 7 to 14. Table 60 shows the relation between the register value and the interval between each frame. Table 60. Frame interval, according to the sfd_rate value sfd_rate value Time frame (s) Max frames per second 7 2.05E-3 488.28 8 4.10E-3 244.17 9 8.19E-3 122.07 10 1.64E-2 61.04 11 3.28E-2 30.52 12 6.55E-2 15.26 13 1.31E-1 7.63 14 2.62E-1 3.81 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 55 AFE status registers 9.3 AFE status registers 9.3.1 output[FRONTEND_Stage_0][XYZ] These registers' bits are shown in the following table. Table 61. output[FRONTEND_Stage_0][XYZ] registers 0x00(MSB) Offset Bit 7 6 5 4 3 0x01(LSB) 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_0][X] output[FRONTEND_Stage_0][X] Reset 0x00 0x00 Offset 0x02(MSB) 0x03(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_0][Y] output[FRONTEND_Stage_0][Y] Reset 0x00 0x00 Offset 0x04(MSB) 0x05(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_0][Z] output[FRONTEND_Stage_0][Z] Reset 0x00 0x00 1 0 1 0 1 0 Table 62. output[FRONTEND_Stage_0][XYZ] bit description Field Description Normalized accelerometer data sampled at the default rate with complete bandwidth. 7:0 Units: 0.244 mg/LSB. output[FRONTEND_Stage_0][XYZ] Range of valid values: -32,768 to 32,767. 9.3.2 output[FRONTEND_Stage_1][XYZ] These registers' bits are shown in the following table. Table 63. output[FRONTEND_Stage_1][XYZ] registers 0x06(MSB) Offset Bit 7 6 5 4 3 0x07(LSB) 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_1][X] output[FRONTEND_Stage_1][X] Reset 0x00 0x00 Offset 0x08(MSB) 0x09(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_1][Y] output[FRONTEND_Stage_1][Y] Reset 0x00 0x00 1 0 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 56 Freescale Semiconductor, Inc. AFE status registers Table 63. output[FRONTEND_Stage_1][XYZ] registers (Continued) 0x0A(MSB) Offset Bit 7 6 5 4 3 0x0B(LSB) 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_1][Z] output[FRONTEND_Stage_1][Z] Reset 0x00 0x00 1 0 1 0 Table 64. output[FRONTEND_Stage_1][XYZ] bit description Field Description Normalized accelerometer data sampled at the default rate of half bandwidth. 7:0 Units: 0.244 mg/LSB. output[FRONTEND_Stage_1][XYZ] Range of valid values: -32,768 to 32,767. 9.3.3 output[FRONTEND_Stage_0_ABS][XYZ] These registers' bits are shown in the following table. Table 65. output[FRONTEND_Stage_0_ABS][XYZ] registers 0x0C(MSB) Offset Bit 7 6 5 4 3 0x0D(LSB) 2 1 0 7 6 5 4 3 2 Field output[FRONTEND_Stage_0_ABS][X] output[FRONTEND_Stage_0_ABS][X] Reset 0x00 0x00 Offset 0x0E(MSB) 0x0F(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_ABS][Y] output[FRONTEND_Stage_0_ABS][Y] Reset 0x00 0x00 Offset 0x10(MSB) 0x11(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_ABS][Z] output[FRONTEND_Stage_0_ABS][Z] Reset 0x00 0x00 0 0 Table 66. output[FRONTEND_Stage_0_ABS][XYZ] bit description Field Description 7:0 output[FRONTEND_Stage_0_ABS][XYZ] Absolute value normalized accelerometer data sampled at the default rate of complete bandwidth. Units: 0.244 mg/LSB. Range of valid values: 0 to 32,767. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 57 AFE status registers 9.3.4 output[FRONTEND_Stage_0_GM][XYZ] These registers' bits are shown in the following table. Table 67. output[FRONTEND_Stage_0_GM][XYZ] registers 0x12(MSB) Offset Bit 7 6 5 4 3 0x13(LSB) 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_GM][X] output[FRONTEND_Stage_0_GM][X] Reset 0x00 0x00 Offset 0x14(MSB) 0x15(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_GM][Y] output[FRONTEND_Stage_0_GM][Y] Reset 0x00 0x00 Offset 0x16(MSB) 0x17(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_GM][Z] output[FRONTEND_Stage_0_GM][Z] Reset 0x00 0x00 0 0 0 Table 68. output[FRONTEND_Stage_0_GM][XYZ] bit description Field Description Raw accelerometer data sampled at the default rate with complete bandwidth. The resolution depends on the g-mode setting configured by afe_csr[fs]. Units: * 2 g mode: 0.061 mg/LSB * 4 g mode: -0.122 mg/LSB 7:0 output[FRONTEND_Stage_0_GM][XYZ] * 8 g mode: 0.244 mg/LSB Range of valid values: * 2 g mode: 0.061 mg/LSB = -32768 to 32767 * 4 g mode: 0.122 mg/LSB = -8192 to 8192 * 8 g mode: 0.244 mg/LSB = -4096 to 4096 9.3.5 output[FRONTEND_Stage_0_LPF][XYZ] These registers' bits are shown in the following table. Table 69. output[FRONTEND_Stage_0_LPF][XYZ] registers 0x18(MSB) Offset Bit 7 6 5 4 3 0x19(LSB) 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_LPF][X] output[FRONTEND_Stage_0_LPF][X] Reset 0x00 0x00 Offset 0x1A(MSB) 0x1B(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_LPF][Y] output[FRONTEND_Stage_0_LPF][Y] Reset 0x00 0x00 0 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 58 Freescale Semiconductor, Inc. AFE status registers Table 69. output[FRONTEND_Stage_0_LPF][XYZ] registers (Continued) 0x1C(MSB) Offset Bit 7 6 5 4 3 0x1D(LSB) 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_LPF][Z] output[FRONTEND_Stage_0_LPF][Z] Reset 0x00 0x00 0 Table 70. output[FRONTEND_Stage_0_LPF][XYZ] bit description Field Description 7:0 output[FRONTEND_Stage_0_LPF][XYZ] 9.3.6 Normalized accelerometer data sampled at the default rate, with configurable, low-pass filter cutoff. Units: 0.244 mg/LSB. Range of valid values: -32,768 to 32,767. output[FRONTEND_Stage_0_HPF][XYZ] These registers' bits are shown in the following table. Table 71. output[FRONTEND_Stage_0_HPF][XYZ] registers 0x1E(MSB) Offset Bit 7 6 5 4 3 0x1F(LSB) 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_HPF][X] output[FRONTEND_Stage_0_HPF][X] Reset 0x00 0x00 Offset 0x20(MSB) 0x21LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_HPF][Y] output[FRONTEND_Stage_0_HPF][Y] Reset 0x00 0x00 Offset 0x22(MSB) 0x23(LSB) Bit 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 Field output[FRONTEND_Stage_0_HPF][Z] output[FRONTEND_Stage_0_HPF][Z] Reset 0x00 0x00 0 0 0 Table 72. output[FRONTEND_Stage_0_HPF][XYZ] bit description Field Description 7:0 output[FRONTEND_Stage_0_HPF][XYZ] Normalized accelerometer data sampled at the default rate, with configurable, high-pass filter cutoff. Units: 0.244 mg/LSB. Range of valid values: -32,768 to 32,767. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 59 AFE status registers 9.3.7 output_temp This register's bits are shown in the following table. Table 73. output_temp registers 0x24(MSB) Offset 7 Bit 6 5 4 3 0x25(LSB) 2 1 0 7 6 5 4 3 Field output_temp output_temp Reset 0x00 0x00 2 1 0 Table 74. output_temp bit description Field Description 7:0 output_temp Temperature sensor output measurement. Units: ADC counts. output_temp(in count) = -51.4T + 1146, where T is temperature in C Note that this is only a typical characteristic example. User shall perform minimal calibration to adjust at least the offset. Range of valid values: -32,768 to 32,767. 9.3.8 output_EIC This register's bits are shown in the following table. Table 75. output_EIC registers 0x26(MSB) Offset 7 Bit 6 5 4 3 0x27(LSB) 2 1 0 7 6 5 4 3 Field output_EIC output_EIC Reset 0x00 0x00 2 1 0 Table 76. output_EIC bit description Field 7:0 output_EIC Description Output of the external, analog-input conversion value. Units: ADC counts. output_EIC(in count) = 29570 (AN0-AN1) - 122, where AN0-AN1 is in V. Note that this equation is only a typical example, with ADC conversion in 16-bit mode. Range of valid values: -32,768 to 32,767. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 60 Freescale Semiconductor, Inc. AFE status registers 9.3.9 frame_counter This register's bits are shown in the following table. Table 77. frame_counter registers 0x28(MSB) Offset 7 Bit 6 5 4 3 0x29(LSB) 2 1 0 7 6 5 4 3 Field frame_counter frame_counter Reset 0x00 0x00 2 1 0 Table 78. output_EIC bit description Field 7:0 frame_counter Description Provides the number of frames processed at the configured sample rate. It is not a real-time representation because the time that the device remains in the stop mode is not taken into account. The frame counter will restart at zero when it reaches 65,535. Units: Nondimensional. Range of valid values: 0 to 65,535. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 61 10 Data FIFO Application 10.1 Overview of Data FIFO application The Data FIFO (First In First Out) application is a buffer intended to store the output data from an application. Every scheduler interval, the Data FIFO application gathers the output data from an application and stores it until the host processor reads the data. Application ID Default speed Configuration The FIFO application uses the mailboxes differently than other applications--operating in registers the streaming mode. In streaming mode, the host continues reading data until a maximum of up to 255 bytes is read per host request. The host must read all the data that it requested. Status The FIFO can be connected to one application and can collect packets of data in different registers sizes (one, two, four, or six bytes). 0x0F 30 Hz. Start on page 67. Start on page 69. The Data FIFO has two different modes of operation: Stop on Overflow and Free Run. The application's status register displays current status values such as overflow condition, watermark reached, and buffer empty. These conditions have a flag that is asserted individually each time one of these conditions occurs. The user can configure the FIFO buffer size by writing to the fifo_size word within the configuration registers. The buffer size can be configured only once and is limited by the amount of RAM available. The amount of available RAM can be impacted by the Event Queue Application which also can be configured to use large amounts of RAM. NOTE Before configuring the Data FIFO application, it is recommended that the Data FIFO Application be suspended. After the parameter is configured, remove the application from suspend. A suspend is done with the Reset/Suspend/Clear Application (APP_ID 0x17). 10.2 Modes of operation This section examines the modes of operation of the FIFO buffer. 10.2.1 Stop-on-overflow The FIFO stores data from an application, every single frame (a scheduler interval), as long as the FIFO is enabled. In this mode, the FIFO stores data until an overflow condition is reached. At an overflow condition, the overflow flag is set. The host asynchronously reads payload packets from the Data FIFO application. Reading payload packets frees up slots for new entries into the FIFO. If the host reads data faster than the applications put data into the FIFO, the overflow condition will never happen. The overflow condition occurs when the available buffer memory is full and there is no space available for another packet. 10.2.2 Free-run The FIFO behaves as a circular buffer that stores data from the configured channel, every single frame, as long as the FIFO is enabled. In this mode, the FIFO never stops storing data, even though the overflow condition is reached and the overflow flag is set. When the FIFO becomes full, the oldest data in the buffer will be overwritten first. 10.3 Reading process To read the data FIFO, the host sends a read-data command to the MMA9555L device that calls the Data FIFO application, stores the requested data within the FIFO into a buffer, and returns the number of bytes read. The data FIFO does not tag each entry with a timestamp, only storing a timestamp for the last entry. When the reading process is performed, the Data FIFO application calculates the timestamp for the first group of requested data and appends the timestamp to the data. If the host requests N bytes and that is bigger than the entry size, the pop routine will MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 62 Reading process append the timestamp only for the first entry that fits in the N bytes requested. The host must calculate the timestamps for the extra entries requested within the N bytes. The host can request to read up to 255 bytes at a time. Assuming the AFE is providing data, this is exactly 36 packets of AFE data. Each host, FIFO-read transaction includes a status byte and a timestamp word. These three bytes are prefixed to the payload data. Payload data is prefixed with the APP_ID of the application that has provided the data. In the AFE case, the APP_ID is 0x06. (255 - 3 (status and timestamp) ) / 7 (APP_ID + 6 byte XYZ data) = 36 Reading the FIFO example The device powers up in Sleep mode, but it may become necessary to wake the MMA9555L device. Waking the device uses the following mailboxes: MB0: 0x12, App_ID = 0x12; Power Controller modes MB1: 0x20, Command 0x20 = Write configuration; Offset = 0 MB2: 0x06, Offset = 0x06 MB3: 0x01, Count of data to write MB4: 0x00, Actual Data Value; Clears sleep bit Bytes to Send: 0x12, 0x20, 0x06, 0x01, 0x00. Example 9. To configure for FIFO operation, write the following transaction to the Data-FIFO application: 1. MB0: Set APP_ID to (0x0F). Selects the Data-FIFO application. 2. MB1: Command to (0x20). Command is a Write Configuration space. 3. MB2: Set offset to zero (0x00). Start writing configuration values at register 0. 4. MB3: Set count field to (0x0A). Sends nine bytes. 5. MB4: Send Data (0x0C). Sends six bytes, free-run mode. 6. 7. 8. 9. 10. MB5: Send Data (0x00). MB6: Send Data (0x00). MB7: Send Data (0x00). MB8: Send Data (0x00). MB6: Send Data (0x3C). Reserves 60 bytes--10 packets of six bytes each. 11. MB7: Send Data (0x06). Associates APP ID = AFE - . 12. MB5: Send Data (0x00). 13. MB6: Send Data (0x00). 14. MB7: Send Data (0x00). Bytes to Send: 0x0F, 0x20, 0x00, 0x0A, 0x0C, 0x00, 0x00, 0x00, 0x00, 0x3C, 0x06, 0x00, 0x00, 0x00. The configuration registers can only be written once. To reconfigure the FIFO, the device first must be reset. Read the FIFO applications status register to get the data. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 63 Reading process Send the following command to set up for reading the status register. Example 10. 1. MB0: Set APP_ID to (0x0F). Selects the Data-FIFO application. 2. MB1: Command to (0x30). Sends a Read Status space command. 3. MB2: Set offset to zero (0x03). Starts reading the configuration values from register 0x03. 4. MB3: Set count field to (0x0A). Reads 10 bytes (three status bytes, one APP_ID, and six bytes of data). Bytes to Send: 0x0F, 0x30, 0x03, 0x0A. This results in the following response. 0F 80 0A 0A 05 83 13 06 00 81 FF EA 11 0C The last six bytes are the AFE data: X, Y, and Z. This response was with the device flat, in the Face-Up orientation. The X and Y data are close to 0x0000, or 0 g, and the Z data is close to 0x1000, or 1 g. MB0: APP_ID = 0x0F; FIFO application MB1: STATUS = 0x80; Command Complete, no errors MB2: RequestedData count = 0x0A; 10 bytes of data MB3: Actual Data Count = 0x0A; 10 bytes of data MB4: 0x05 = FIFO Status; Watermark and Overflow flag is set MB5-MB6: = 0x8313; Timestamp MB7: APP ID of the application providing the actual data = 0x06; AFE application MB8-MB9: AFE X data; 0x0081 MB10-MB11: AFE Y data; 0xFFEA MB12-MB13: AFE Z Data; 0x110C The read size for one (1+6 byte) payload is 10 bytes. The size for two payloads is 17 bytes, 3 = 24 bytes. Reading three payloads Send the following command to set up for reading the status register. Example 11. 1. MB0: Set APP_ID to (0x0F). Selects the Low-g application. 2. MB1: Command to (0x30) Sends a Write Configuration space command. 3. MB2: Set offset to zero (0x03). Starts writing configuration values at register 0. 4. MB3: Set count field to (0x18) Reads 24 bytes (3 status byes + 3x(APP_ID+6 data)). Bytes to Send: 0x0F, 0x30, 0x03, 0x18. The response is below: 0F 80 18 18 05 33 53 06 00 93 00 7F 11 06 06 00 A2 00 7D 11 08 06 00 9C 00 79 11 07 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 64 Freescale Semiconductor, Inc. Reading process The last six bytes are the AFE data, X, Y, and Z. This response was with the device flat, in the Face-Up orientation. The X and Y data are close to 0x0000--or 0-g--and the Z data is close to 0x1000--or 1-g. MB0: APP_ID = 0x0F; FIFO application MB1: STATUS = 0x80; Command Complete, no errors MB2: Requested data count = 0x18; 24 bytes of data MB3: Actual Data Count = 0x18; 24 bytes of data MB4: 0x05 = FIFO Status; Watermark and Overflow flag is set MB5-6: = 0x3353; Timestamp MB7: APP ID of the application providing the actual data = 0x06; The AFE application MB8-9: AFE X data; 0x0093 MB10-11: AFE Y data; 0x007F MB12-13: AFE Z Data; 0x1106 MB14: APP ID of the application providing the actual data = 0x06; the AFE application MB15-16: AFE X data; 0x00A1 MB17-18: AFE Y data; 0x007D MB19-20: AFE Z Data; 0x1108 MB21: APP ID of the application providing the actual data = 0x06; the AFE application MB22-23: AFE X data; 0x009C MB24-25: AFE Y data; 0x0079 MB26-27: AFE Z Data; 0x1107 To read data stored by the data FIFO application, the host must send a Read Data command along with a specific offset value. This process has three conditions: * The offset must be fixed to three * The number of bytes to read must be larger than one and a multiple of the entry size * The host must add three bytes to de-count the total bytes to read Failure to adhere to the three conditions above could cause the data FIFO to enter into an error state and be unable to pop coherent data. To recover the data FIFO, reset the flag in the Reset_control byte (APP_ID 0x17). When the command is sent, the first four bytes that the MMA9555L device returns correspond to the response of the command. The next byte gives the status of the data FIFO application module and the following two bytes represent the timestamp; thus the three-byte offset. These bytes are part of those requested by the host, so it is very important that the user add three bytes to the number of bytes to read. The data stored in the data FIFO comes after these seven bytes. If the module is storing data at the exact moment that a read is issued by the host, the MMA9555L device will return an error condition (A2). When this occurs, the host must retry reading the data. If any other error is returned, the host must take the proper action. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 65 Data FIFO block diagram 10.4 Data FIFO block diagram Frame counter TimeStamp register APP_ID = nn Watermark level FIFO buffer (Host decides the size in bytes) Mode * Stop on overflow * Free run FIFO size Entry size Records number WM flag OvF flag Empty flag GPIO mapping logic Interrupt Figure 16. Data FIFO model Figure 16 shows the block-level model of the data FIFO. The application is driven by the watermark and mode inputs that configure the functionality. The watermark level helps the host prevent data loss by raising a warning just before the overflow condition occurs. When the number of bytes in the buffer approaches its capacity, the data FIFO asserts the watermark flag in the status register. The watermark level is user-configurable. If the level of 0 is configured, the watermark is disabled. The channel has its own data format code (DFC) bit field that configures the payload to be stored (one, two, four, or six bytes). A NULL or zero value in the APP_ID Channel register means the channel is disabled. Any valid APP_ID value means the channel is enabled. The data FIFO has a status register in its output structure that contains status flags such as watermark, overflow, and buffer empty. These flags can be mapped to the GPIO pins to generate an interrupt to the host. The output also has an Entry Size register that shows the size, in bytes, of each entry that the data FIFO calculated, according to its payload configuration. A Records Number register records the number of entries stored in the data FIFO. Both registers help the host to calculate how many bytes to request, so that it can dump the entire FIFO buffer. A simple multiplication of those two registers' value gives the total number of bytes stored in the FIFO. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 66 Freescale Semiconductor, Inc. Data FIFO configuration registers 10.4.1 Entries format Channel enabled Size defined by DFC1 (1, 2, 4, or 6 bytes) Entry 1 APP_ID (1 byte) Payload (N bytes) Entry 2 APP_ID (1 byte) Payload (N bytes) APP_ID (1 byte) Payload (N bytes) * * * Entry M Figure 17. FIFO-entry formats, when channel enabled 10.5 Data FIFO configuration registers This section contains the FIFO configuration registers. These registers can only be written once. To reconfigure the FIFO, the device must be reset. This is because the FIFO application requests RAM and RAM can only be allocated once. 10.5.1 FIFO configuration byte Table 79. FIFO Config Byte register 0x00 Offset 7 Bit 6 5 4 3 2 1 0 Field Reserved DFC1 Mode Reset 0x00 0x00 0x00 Table 80. FIFO Config Byte bit descriptions Field Reserved 3:2 DFC1 (Data Format Code) 1:0 Mode Description Bit field reserved. Configures the payload size of the channel. Units: None. Range of valid values: 0 to 3. * * * * 00: One byte. 01: Two bytes. 10: Four bytes 11: Six bytes. Configures the FIFO mode. Units: None. Range of valid values: * 00: Free Run. * 01: Stop On Overflow. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 67 Data FIFO configuration registers 10.5.2 FIFO size word Table 81. FIFO-size word registers 0x04(MSB) Offset Bit 7 6 5 4 3 0x05(LSB) 2 1 0 7 6 5 4 3 2 Field FIFO Size Word 1 FIFO Size Word 2 Reset 0x00 0x00 1 0 Table 82. FIFO-size word bit description Field Description 7:0 FIFO Size Word Reserves the maximum size (in bytes) that the FIFO can use. This is limited by the available RAM. Units: Bytes. Range of valid values: 0 to available RAM. 0x1C8 (decimal, 456) is the maximum amount of RAM that can be requested from the MMA9555L device. The RAM is shared by multiple applications, so be careful not to set the FIFO to use more memory than is physically available. That will cause unknown and undesirable results. 10.5.3 FIFO APP_ID Table 83. FIFO Channel APP_ID register 0x06 Offset 7 Bit 6 5 4 3 2 Field FIFO Ch APP_ID Reset 0x00 1 0 Table 84. FIFO Channel APP_ID bit description Field Description 7:0 The APP_ID of the application that supplied data to be buffered by the FIFO. FIFO Ch APP_ID Range of valid values: 0 to 0xFF. 10.5.4 Watermark Table 85. Watermark registers 0x08(MSB) Offset Bit 7 6 5 4 3 0x09(LSB) 2 1 0 7 6 5 4 3 Field Watermark Watermark Reset 0x00 0x00 2 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 68 Freescale Semiconductor, Inc. Data FIFO status registers Table 86. Watermark bit description Field Description Sets the count, in bytes, for the FIFO to set or clear the watermark flag. Units: Bytes. Range of valid values: 0-available RAM. 7:0 Watermark 10.6 Data FIFO status registers 10.6.1 Records number Table 87. Records-number register 0x00(MSB) Offset 7 Bit 6 5 4 0x01(LSB) 3 2 1 0 7 6 5 4 3 2 Field Records Number Records Number Reset 0x00 0x00 1 0 Table 88. Records-number bit description Field Description 7:0 Records Number This word stores the current number of records in the FIFO buffer. A record is the payload packet of data comprised of an APP_ID and the actual data--which could be one, two, four, or six bytes long. A record can be two, three, four, or seven bytes long. Units: Number of entries in the Data FIFO (entry size in bytes = Ch APP_ID+ DFC1). Range of valid values: 0 to available oxFFFF. 10.6.2 Entry size Table 89. Entry-size register 0x02 Offset Bit 7 6 5 4 3 Field Entry Size Reset 0x00 2 1 0 Table 90. FIFO config-byte/bit description Field 7:0 Entry Size Description This byte shows the size in bytes of each entry that the data FIFO has stored, that calculation based on its configuration. Units: Bytes. Range of valid values: 0 to 6. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 69 Data FIFO status registers 10.6.3 FIFO_Status Table 91. FIFO_Status register 0x03 Offset 7 Bit Field 6 5 on_going_push on_going_pop Reset 0x00 0x00 4 3 2 1 0 Reserved ovf_flag empty_ flag wmrk_ flag 0x00 0 0 0 Table 92. FIFO_Status bit descriptions Field 7 fifo_on_going_push 6 fifo_on_going_pop 5:3 Reserved 2 fifo_ovf_flag Description Indicates that a push operation is being executed--the is FIFO receiving data from the application. Units: Nondimensional. Range of valid values: 0 to 1. * 0: A push is not being executed. * 1: A push is being executed. Indicates that a pop operation is being executed. The FIFO is sending out data and it is being read. Units: Nondimensional. Range of valid values: 0 to 1. * 0: A pop operation is not being executed. * 1: A pop operation is being executed. Bit field reserved. Indicates that FIFO buffer has reached the maximum number of entries allowed. This meaning can vary depending of the mode of operation. Units: Nondimensional. Range of valid values: * 0: Not overflow condition. * 1: Overflow condition. 1 fifo_empty_flag 0 fifo_wmrk_flag Indicates whether the FIFO buffer is empty. Units: Nondimensional. Range of valid values: * 0: FIFO buffer is not empty. * 1: FIFO buffer is empty. Indicates when the entries in the FIFO buffer have reached the watermark count. Units: Nondimensional.. Range of valid values: * 0: Watermark not reached. * 1: Watermark reached. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 70 Freescale Semiconductor, Inc. 11 Event Queue Application 11.1 Application ID Overview of Event Queue application This application manages a queue of asynchronous events. The size of the queue is flexible and can be configured by writing to the queue_size word within the configuration registers Default speed of the Event Queue Application. Configuration The size of the Event Queue is limited by the available RAM. The amount of RAM may be registers reduced by the Data FIFO Application which also can be configured to use the RAM. Some applications inside the MMA9555L platform have an eight-bit event-mask register within configuration-registers structure that selects the specific event to be stored into the Event Queue. The user can set an application's event-mask bit to enable or prevent that application's events from being added to the Event Queue. Status registers 0x10 30 Hz. Start on page 74. Start on page 76. When the selected event happens, Event Queue Application calls a routine with the following prototype to push the application's event into the Event Queue: void eventQueue_push(void *data, uint8_t size) With these variables: * Data: Pointer to the first element of the data to be stored into the queue. The data must have the order: APP_ID + Payload bytes. * Size: Amount of data (in bytes) to be stored into the queue. Each entry into the Event Queue is of fixed size and has the following format: 'SBNF$PVOUFS "11*% 1BZMPBE 4JYCZUFTQFSFOUSZ Figure 18. Entry format for the Event Queue If an application's payload is less than three bytes, the Event Queue will store the data and complete the entry padding with zeros. If the application has a payload more than three bytes, the Event Queue will calculate the number of entries that this payload needs to be successfully stored, split in the format shown in Figure 18. If an application tries to push data into the Event Queue and there is not enough space to store it, the Event Queue will ignore the attempt. This will be transparent for the application since there is no communication between the application and the Event Queue. 11.1.1 Modes of operation The Event Queue works only in one mode. It stores data and stops when the end of the queue is reached and asserts an overflow flag. The queue is not circular. The application has a configurable watermark that asserts a flag when entries have reached the configured point. 11.1.2 Reading process To read the Event Queue, the host sends a read-status command to the MMA9555L device, calling the Event Queue application that stores the data within the queue into a buffer and returns the number of bytes read. If the number of requested bytes is not a multiple of the entry size, the pop routine ignores the extra bytes and tells the host how many effective bytes were popped. To read data stored by the Event Queue application, the host must send a Read Data command along with a specific offset value. The following examples show the command for reading the data stored by the Event Queue Application. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 71 Overview of Event Queue application Reading Event Queue example The following example shows how to configure the Event Queue application. Example 12. 1. MB0: Set APP_ID to (0x10). Selects the Data-FIFO application. 2. MB1: Command to (0x20). Sends a Write Configuration space command. 3. MB2: Set offset to zero (0x00). Starts writing configuration values at register 0. 4. MB3: Set count field to (0x06). Sends nine bytes. 5. MB4: Send Data (0x00). Sets Queue size. 6. MB5: Send Data (0x50). 7. MB6: Send Data (0x00). Watermark 8. MB7: Send Data (0x05). 9. MB8: Send Data (0x00). Timeout. 10. MB6: Send Data (0x00). Bytes to Send: 0x10, 0x20, 0x00, 0x06, 0x00, 0x50, 0x00, 0x05, 0x00, 0x00. The configuration registers can only be written once. If the Event Queue must be reconfigured, the device must be reset and the configuration rewritten. Some data now must be sent to the event queue. In this example, the Low-g application is configured to send an event. Example 13. 1. 2. 3. 4. 5. 6. MB0: Set APP_ID to (0x09). Specifies the Low-g application. MB1: Command to (0x20). Sends a Write Configuration space command. MB2: Set offset to zero (0x09). Start writing configuration values at Register 9. MB3: Set count field to (0x01). Sends nine bytes. MB4: Send Data (0x08) - Event Mask Register. Enables Low-g events. Bytes to Send: 0x09, 0x20, 0x09, 0x01, 0x08. In this example, all other Low-g configuration register values are at the reset default values. The device powers up in Sleep mode, but it may become necessary to wake the part. That process is done in the following example. Example 14. 1. 2. 3. 4. MB0: Set App_ID to (0x12). Selects the Power Controller modes. MB1: Command to (0x20). Sends a write configuration, with offset = 0. MB2: Set offset to (0x06). MB3: Set count field to (0x01). MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 72 Freescale Semiconductor, Inc. Overview of Event Queue application 5. MB4: Send the data value (0x00). Bytes to Send: 0x12, 0x20, 0x06, 0x01, 0x00. The device is enabled and configured to have an event Queue and send Low-g events to the Event Queue. To cause a Low-g event that can be measured on the X, Y, and Z axes, toss the board into the air. Read the Event Queue applications status register to get the data. To set up for reading the status register, send the command in the following example. Example 15. 1. 2. 3. 4. MB0: Set APP_ID to (0x10). Selects the Event Queue application. MB1: Command to (0x30). Sends a Read Status space command. MB2: Set offset to zero (0x03). Start reading status values at register 0. MB3: Set count field to (0x20). Reads 10 bytes (3 status + APP_ID+6 data) Bytes to Send: 0x10, 0x30, 0x03, 0x20. The following response is returned: 10 80 13 20 09 95 AC 09 0F 00 00 95 BE 09 0F 00 00 95 D0 09 0F 00 00 MB0: APP_ID = 0x10; Event Queue application MB1: STATUS = 0x80; Command Complete, no errors MB3: Actual Data Count = 0x13; 10 bytes of data MB2: Requested Data count = 0x20; 10 bytes of data MB4: 0x09 = Event Queue Status; Watermark and Overflow flags are set MB5-MB6: = 0x95AC; Timestamp MB7: APP ID of the application providing the actual data = 0x09; the AFE application MB8-MB10: 0x0F0000 = 0x0F is the status register from the Low-g applications; 0x0F indicates a Low-g event on all axes. MB5-MB6: = 0x95BE; Timestamp MB7: APP ID of the application providing the actual data = 0x09; the AFE application MB8-MB10: 0x0F0000 MB5-MB6: = 0x95D0; Timestamp MB7: APP ID of the application providing the actual data = 0x09; the AFE applications MB8-MB10: 0x0F0000 The offset is fixed to three bytes. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 73 Event Queue configuration registers When the command is sent, the first four bytes that the MMA9555L device returns correspond to the response of the command. The fifth byte is the status from the Event Queue application. This byte is part of the bytes requested by the host, therefore it is very important that the user adds one byte to the number of bytes to be read. Due to the application's read functionality, if the application is storing data at the exact moment a read is issued by the host, the MMA9555L device will return an error condition. When this occurs, the host must retry reading the data. If any other error is returned, the host must take the proper action. 11.1.3 Event Queue block diagram The following figure shows the Event Queue Data Flow Model that receives the Application ID and the N size of the payload from a specific application. The Event Queue logic appends the frame counter with this data and pushes the entry (six bytes in size) into the queue. If the queue is full, the logic will ignore the push request. APP (AP_ID) 16-bit frame count AP_ID Payload Queue processing Various elements in the application can set or clear bits in this register. Data Array Host decides the size (in bytes) Event_Queue_Flag Register Logical AND Event_Queue_Mask Register Event_Queue_Flag Register Config command can Modify this register. Frame Counter Command calls a pop routine to dump the memory. Full WM First entry (after reset) GPIO mapping logic Interrupt Payload N AP_ID - Payload N Push subroutine Config command can modify this table. Figure 19. Event Queue data flow 11.2 Event Queue configuration registers The Event Queue application's configuration can only be written once. In order to reconfigure the Event Queue, the whole device must be reset. This is because the Event Queue application requests RAM and RAM can only be allocated once. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 74 Freescale Semiconductor, Inc. Event Queue configuration registers 11.2.1 queue_size Table 93. queue_size registers 0x00(MSB) Offset 7 Bit 6 5 4 3 0x01(LSB) 2 1 0 7 6 5 4 3 2 1 0 queue_size Field Reset Table 94. queue_size bit description Field Description 7:0 queue_size Defines the size in bytes that the Event Queue will reserve, in order to store the data sent by any application. Units: Bytes Range of valid values: 0-available RAM. 0x1C8 (decimal 456) is the maximum amount of RAM that can be requested from the MMA9555L device. The RAM is shared by multiple applications, so be careful not to set the FIFO to use more memory than is physically available. That will cause unknown and undesirable results. 11.2.2 queue_wmrk Table 95. queue_wmrk registers 0x02(MSB) Offset Bit 7 6 5 4 3 0x03(LSB) 2 1 0 7 6 5 4 3 2 1 0 2 1 0 queue_wmrk Field Reset Table 96. queue_wmrk bit description Field Description 7:0 queue_wmrk 11.2.3 Sets the count, in bytes, for the Event Queue to set or clear the watermark flag. Units: Bytes. Range of valid values: 0 to available bytes in the buffer. queue_timeout Table 97. queue_timeout registers 0x04(MSB) Offset Bit 7 6 Field 5 4 3 0x05(LSB) 2 1 0 7 6 5 4 3 queue_timeout Reset MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 75 Event Queue status registers Table 98. queue_timeout bit description Field Description 7:0 queue_timeout 11.3 Sets the count, in cycles, for the Event Queue to set or clear the time-out flag. Units: Time; [queue_timeout] * [1/SRqueue] ). Range of valid values: 0 to 65,535. SR_queue is the sample rate of the Event Queue application, which defaults to 30 Hz. Event Queue status registers 11.3.1 records_number Table 99. records_number registers 0x00(MSB) Offset 7 Bit 6 5 4 3 0x01(LSB) 2 1 0 7 6 5 4 3 2 1 0 records_number Field Reset Table 100. records_number bit description Field Description 7:0 records_number 11.3.2 Shows the current number of entries or records stored in the queue. Units: Entries (Entry = six bytes). Range of valid values: 0 to 65,535. Typically, this number should not be more than the available RAM divided by the payload size. entry_size Table 101. entry_size registers 0x02 Offset Bit 7 6 5 4 3 2 1 0 Set-bit values 0 0 0 0 0 1 1 0 0 1 1 0 entry_size Field Reset 0 0 0 0 Table 102. entry_size bit description Field Description 7:0 entry_size Shows the size in bytes of each entry or record in the queue. This value is six bytes fixed and is not userconfigurable. Units: Bytes. Range of valid values: Fixed to six. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 76 Freescale Semiconductor, Inc. Event Queue status registers 11.3.3 queue_status Table 103. queue_status registers 0x03 Offset Bit 7 6 Field on_going_push on_going_pop 5 4 Reserved 3 2 1 0 to_flag ovf_flag empty_flag wmrk_flag Reset Table 104. queue_status bit descriptions Field Description 7 on_going_push Indicates that a push operation is being executed. Units: Nondimensional. Range of valid values: 0 to 1. 6 on_going_pop Indicates that a pop operation is being executed. Units: Nondimensional.. Range of valid values: 0 to 1. 5:4 Reserved Bit field reserved. 3 to_flag Indicates when the Event Queue has not been read for the time configured by the queue_TimeOut parameter once the overflow marker has been reached. Units: Nondimensional. Range of valid values: 0 to 1. 2 ovf_flag Indicates when the Event Queue is full and no more entries can be stored. Units: Nondimensional. Range of valid values: 0 to 1. 1 empty_flag Indicates when the Event Queue is empty, no records or entries having been stored. Units: Nondimensional. Range of valid values: 0 to 1. 0 wmrk_flag Indicates when the number of bytes within the Event Queue has reached the watermark. Units: Nondimensional. Range of valid values: 0 to 1. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 77 12 Status Register Application 12.1 Overview of Status Register application The Status Register Application provides a simple way for users to combine specific status information bits from multiple applications and read that combined information from one place. The Status Register Application configures the output of its status register by mapping a specific status register bit to a specific output bit of a specific application. This enables the Status Register Application to provide a combined status from the selected bits of userspecified applications. There are eight, user-configurable bits in the Status Register. Each bit mirrors an output bit in the related application. 12.2 Application ID 0x11 Default speed 30 Hz. Configuration registers Start on page 78. Status registers Start on page 82. Status Register configuration registers The following tables show the configuration registers for the Status Register Application. The bit descriptions are given in Table 122 on page 82. 12.2.1 APP_ID SR_00 Table 105. APP_ID SR_00 register 0x00 Offset Bit 7 6 5 4 3 Field APP_ID SR_00 Reset 0x07 12.2.2 2 1 0 2 1 0 2 1 0 Output_Bit_ID SR_00 Table 106. Output_Bit_ID SR_00 register 0x01 Offset Bit 7 6 5 4 3 Field Output_Bit_ID SR_00 Reset 0x00 12.2.3 APP_ID SR_01 Table 107. APP_ID SR_01 register 0x02 Offset Bit 7 6 5 4 3 Field APP_ID SR_01 Reset 0x07 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 78 Status Register configuration registers 12.2.4 Output_Bit_ID SR_01 Table 108. Output_Bit_ID SR_01 register 0x03 Offset Bit 7 6 5 4 3 Field Output_Bit_ID SR_01 Reset 0x01 12.2.5 2 1 0 2 1 0 2 1 0 2 1 0 APP_ID SR_02 Table 109. APP_ID SR_02 register 0x04 Offset Bit 7 6 5 4 3 Field APP_ID SR_02 Reset 0x07 12.2.6 Output_Bit_ID SR_02 Table 110. Output_Bit_ID SR_02 register 0x05 Offset Bit 7 6 5 4 3 Field Output_Bit_ID SR_02 Reset 0x02 12.2.7 APP_ID SR_03 Table 111. APP_ID SR_03 register 0x06 Offset Bit 7 6 5 4 3 Field APP_ID SR_03 Reset 0x07 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 79 Status Register configuration registers 12.2.8 Output_Bit_ID SR_03 Table 112. Output_Bit_ID SR_03 register 0x07 Offset Bit 7 6 5 4 3 Field Output_Bit_ID SR_03 Reset 0x03 12.2.9 2 1 0 2 1 0 2 1 0 2 1 0 APP_ID SR_04 Table 113. APP_ID SR_04 register 0x08 Offset Bit 7 6 5 4 3 Field APP_ID SR_04 Reset 0x07 12.2.10 Output_Bit_ID SR_04 Table 114. Output_Bit_ID SR_04 register 0x09 Offset Bit 7 6 5 4 3 Field Output_Bit_ID SR_04 Reset 0x04 12.2.11 APP_ID SR_05 Table 115. APP_ID SR_05 register 0x0A Offset Bit 7 6 5 4 3 Field APP_ID SR_05 Reset 0x00 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 80 Freescale Semiconductor, Inc. Status Register configuration registers 12.2.12 Output_Bit_ID SR_05 Table 116. Output_Bit_ID SR_05 register 0x0B Offset 7 Bit 6 5 4 3 Field Output_Bit_ID SR_05 Reset 0x00 2 1 0 2 1 0 2 1 0 2 1 0 12.2.13 APP_ID SR_06 Table 117. APP_ID SR_06 register 0x0C Offset 7 Bit 6 5 4 3 Field APP_ID SR_06 Reset 0x07 12.2.14 Output_Bit_ID SR_06 Table 118. Output_Bit_ID SR_06 register 0x0D Offset 7 Bit 6 5 4 3 Field Output_Bit_ID SR_06 Reset 0x06 12.2.15 APP_ID SR_07 Table 119. APP_ID SR_07 register 0x0E Offset 7 Bit 6 5 4 3 Field APP_ID SR_07 Reset 0x00 Table 120. APP_ID SR_07 register description Field Description 7:0 APP_ID (APP_ID SR_n) The application identifier. Zero value and 0xFF are reserved. Units: None. Range of valid values: [0 to 31] and 0xFF, realistically up to 0x1F, refer to the App-ID table MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 81 Status Register default configuration 12.2.16 Output_Bit_ID SR_07 Table 121. Output_Bit_ID SR_07 register 0x0F Offset 7 Bit 6 5 4 3 2 Field Output_Bit_ID SR_07 Reset 0x00 1 0 Table 122. Output_Bit_ID SR_07 register description Field Description 7:0 Bit_ID (Output_Bit_ID SR_n) 12.3 The bit number to be mapped on the Status Register bit n. Units: None. Range of valid values: [0 to 255], refer to the register memory map of each application Status Register default configuration After reset, the status register configuration registers contain the Data Ready and Command Complete bits. NOTE The upper two bits in the upper byte are fixed, but the lower eight bits in the lower byte can be remapped by the user to any application and bits. Table 123. Status Register MSB 0x00 Offset Bit 15 14 13 12 11 10 9 8 Field Command Complete Data Ready N/A N/A N/A N/A N/A N/A 2 1 0 Reset Table 124. Status Register LSB 0x01 Offset Bit 7 6 5 Field Unassigned Reserved Unassigned 4 3 Reserved Reset MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 82 Freescale Semiconductor, Inc. 13 Sleep/Wake Application 13.1 Application ID Overview of Sleep/Wake application This application configures and controls the power-control modes of the accelerometer provides configuration flexibility for minimizing power consumption. 0x12 Default speed The application has three modes of operation: Run, Doze, and Sleep. The Sleep/Wake Configuration module puts the accelerometer into Doze mode automatically when no movement is registers detected. When a change in orientation or movement above the threshold is detected for the specified time period, the application returns to the Run mode. Status To save a significant amount of power, only run the calculation-intensive applications when registers the accelerometer is in motion. 30 Hz. Start on page 84. Start on page 87. Using the activity level settings, some tasks may easily be bypassed when the accelerometer is sleeping. For example, it may not be necessary to run the Pedometer application while the device is sitting undisturbed flat on a desktop. 13.1.1 Run mode In Run mode, all applications are scheduled to run at their maximum established frame rate. An application enters Run mode if the following conditions are met: * The GPIO interrupt is asserted (RGPIO4/INT) * A write command is issued from the host to the MMA9555L * Movement above the threshold is detected and the previous state was Doze mode Sleep = 1 Run mode, Pedometer application executing Sleep mode, nothing done Sleep = 0 Movement above threshold detected Sleep = 1 No movement or host command for the short configured time Doze mode, long time between AFE samples Some movement detected Doze mode, short time between AFE samples No movement or host command for the short configured time 0 Hz SR 1/(long time) Hz SR Average sample rate 1/(short time) Hz SR 30 Hz SR Figure 20. MMA9555L's power modes state diagram MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 83 Sleep/Wake configuration registers 13.1.2 Doze mode In Doze mode, the application only executes four AFE samples at a sample rate defined by the user. The user can configure two sample rate values: long time and short time. These parameters are configured in the long_time_off and short_time_off registers, respectively. The short-time sample rate is used when the sensor detects some movement, but not enough to change to Run mode. The long-time sample rate is used when the Sleep/Wake module detects no movement in the accelerometer. The application enters Doze mode when the Sleep/Wake module detects no movement in the accelerometer for a specified period of time. The amount of time is configured in the doze_thresh register. 13.1.3 Sleep mode In Sleep mode, the MMA9555L device does nothing and remains in the lowest power mode. The device can enter this mode only when the user sets the SNCEN bit from the cfg configuration register or when the application starts. Since the SNCEN bit is set by default, the application starts in Sleep mode. To exit the Sleep mode, the user must clear the SNCEN bit from the cfg configuration register. This is done by issuing the corresponding write configuration command through the slave communications interface. 13.2 Sleep/Wake configuration registers The following sections give the configuration registers for the Sleep/Wake application. 13.2.1 sensitivity_thresh Table 125. sensitivity_thresh registers 0x00(MSB) Offset 7 Bit 6 5 4 3 Field sensitivity_thresh Reset 0x00 0x01(LSB) 2 1 0 7 6 5 4 3 2 1 0 0 0 0 2 1 0 0 0 0 sensitivity_thresh 1 0 1 0 0 Table 126. sensitivity_thresh bit description Field Description 7:0 sensitivity_thresh 13.2.2 Configures the movement threshold of the application to change from Doze to Run mode. Units: None. Range of valid values: 120 to 300. doze_time_thresh Table 127. doze_time_thresh registers 0x02 (MSB) Offset Bit 7 6 5 3 2 1 0 7 6 5 doze_thresh Field Reset 4 0x03 (LSB) 0 0 0 0 1 4 3 doze_thresh 1 1 1 1 0 1 0 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 84 Freescale Semiconductor, Inc. Sleep/Wake configuration registers Table 128. doze_time_thresh bit description Field Description 7:0 doze_thresh Configures the time that the device must be still before entering Doze mode. For example, if the system sample rate if 488 Hz, then to set a time of 1 second, write 488 (0x1EB) to this register. Units: Algorithm cycles (Time = [Algorithm cycles] * [1/SRPWRCTRL]). Range of valid values: 1 to 65,535 13.2.3 long_time_off Table 129. long_time_off registers 0x04 Offset 7 Bit 6 5 Field Reserved Reset 0x00 4 3 2 1 0 long_time_off [3:0] 0 1 1 1 Table 130. long_time_off bit description Field Description 7:4 Reserved Bit field reserved. Configures the long-time interval between AFE samples when the application is in Doze mode. Units: Time. Range of valid values: from 0 to 10. Long-time values Time (seconds) 3:0 long_time_off 13.2.4 * * * * * * * * * * * 0........................................ 4.1 ms 1...................................... 8.19 ms 2...................................... 16.4 ms 3......................................... 32 ms 4...................................... 65.5 ms 5....................................... 131 ms 6....................................... 162 ms 7....................................... 524 ms 8......................................... 1.05 s 9........................................... 2.1 s 10....................................... 4.19 s short_time_off Table 131. short_time_off register 0x05 Offset Bit 7 6 5 Field Reserved Reset 0x00 4 3 2 1 0 short_time_off [3:0] 0 1 1 0 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 85 Sleep/Wake configuration registers Table 132. short_time_off bit description Field Description 7:4 Reserved Bit field reserved. Configures the short-time interval between AFE samples when the application is in Doze mode. Units: Time. Range of valid values: 0 to 10. Long-time values Time (seconds) 3:0 short_time_off 13.2.5 * * * * * * * * * * * 0........................................ 4.1 ms 1...................................... 8.19 ms 2...................................... 16.4 ms 3......................................... 32 ms 4...................................... 65.5 ms 5....................................... 131 ms 6....................................... 162 ms 7....................................... 524 ms 8......................................... 1.05 s 9........................................... 2.1 s 10....................................... 4.19 s cfg Table 133. cfg register 0x06 Offset Bit 7 6 5 4 3 2 1 0 Field Reserved Stop_DIS IRQ_EN SCHEN FLEEN SNCEN Reset 0x00 0 0 0 0 1 Table 134. cfg bit descriptions Field 7:5 Reserved 4 Stop_DIS 3 IRQ_EN 2 SCHEN Description Bit field reserved. Disables or enables the low-power mode. If this bit is set, the device doesn't execute the STOP assembler instruction even if the SNCEN, FLEEN, or SCHEN bits are set as 1b. * 0: Enables STOP mode. * 1: Disables STOP mode. Enables or disables the IRQ interruption in the GPIO4. * 0: Disables IRQ interruption. * 1: Enables IRQ interruption. Enables or disables the Doze mode. * 0: Disables the Doze mode. * 1: Enables the Doze mode. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 86 Freescale Semiconductor, Inc. Sleep/Wake status registers Table 134. cfg bit descriptions (Continued) Field Description 1 FLEEN 0 SNCEN 13.3 Controls the use of long and short time between AFE samples when in Doze mode. If this bit is cleared, the application does not use the long- and short-time values to determine the time between AFE samples. Instead, the time is fixed as 2.05 ms. * 0: Time between AFE samples fixed at 2.05 ms. * 1: Long- and short-time values determine the time between AFE samples. Enables or disables the Sleep mode. Note: When this bit is set, the device will enter Sleep mode. The device can only exit this mode is by clearing this bit via a configuration-write command. * 0: Disables the Sleep mode. * 1: Enables the Sleep mode. Sleep/Wake status registers 13.3.1 scheduler_mode Table 135. scheduler_mode register 0x00 Offset Bit 7 6 5 4 3 2 Field -- -- -- -- -- -- Reset 0 0 0 0 0 0 1 0 scheduler_mode 0 0 Table 136. scheduler_mode bit description Field 1:0 scheduler_mode Description Shows the scheduler mode when the SCHED and FLEEN bits are set in the cfg register. If those bits are not set, the value of this register may not reflect the actual scheduler mode. Units: None. Range of valid values: 0 to 0x02. * 00: Doze mode. Frame rate determined by the long_time_off configuration register. * 01: Doze mode. Frame rate determined by the short_time_off configuration register. * 10: Run mode. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 87 14 Reset/Suspend/Clear Control Application 14.1 Overview of Reset/Suspend/Clear Control application This application provides a way to reset, suspend, and clear the outputs of the applications in the MMA9555L. The reset and clear functions are implemented in each application as callback functions. The suspend function is handled in the Scheduler Application. One of the requirements of an application on the MMA9555L device is that it has a reset and clear function that can be called by the scheduler or another application. This chapter describes how an application's reset and clear callback functions can be called or triggered. Application ID 0x17 Default speed 30 Hz. Configuration registers Start on page 89. Status registers None. There are three groups of configuration registers for the Reset/Suspend/Clear Control application. 14.1.1 Reset The reset bit, when set, schedules a reset for an application. At the next system cycle, the reset process is handled. The reset bit is automatically cleared by the Scheduler Application. When the reset bit for an application is set, the following actions occur: * The application's reset callback function is executed. The reset function is part of an application and it typically resets the application's outputs and internal variables. * The reset bit is cleared. * The scheduled application is executed. 14.1.2 Suspend The suspend bit, when set, prevents an application from executing while the suspend bit is set. Setting or clearing the suspend flag is managed by the host through a command. To preserve data coherency in an application, the suspend flag must be set before attempting to modify an application's configuration. The bit then must be cleared after the configuration has been changed. 14.1.3 Clear The clear bit clears an application's outputs. The clear flag is automatically cleared by the scheduler. When an application's clear bit is set, it causes the following actions: * The application's clear callback is executed. This typically resets the application's outputs. * The clear flag is cleared. * The application is executed. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 88 Configuration registers for Reset/Suspend/Clear Control applications 14.2 Configuration registers for Reset/Suspend/Clear Control applications 14.2.1 Reset configuration register Table 137. Reset registers (MSB) 0x00 = reset_bits[31:24] Offset 31 Bit 30 29 28 27 Reserved Field 1 Reset 1 1 1 26 25 24 Six-Direction GPIO Input/ Output Reserved 1 1 1 1 0x01 = reset_bits[23:16] Offset Bit 23 22 21 20 19 18 17 16 Field Rst/Susp/ Clr Reserved Pedometer Reserved Reserved Auto-Wake/ Sleep Status Event FIFO Reset 0 1 1 1 1 1 1 1 10 9 8 1 1 1 0x02 = reset_bits[15:8] Offset Bit 15 Field Data FIFO Reset 1 14 13 12 11 Reserved 1 1 1 1 (LSB) 0x03 = reset_bits[7:0] Offset Bit 7 6 5 4 3 2 1 0 Field Reserved AFE Reserved MBOX GPIO_AP PMAP CI Scheduler General Rst Reset 1 1 1 1 1 1 1 1 Table 138. Reset bit descriptions Field 31:27 Reserved 26 Six Direction 25 GPIO Input/Output 24 Reserved Description Not used. * 0: Normal operation. * 1: Initiates the reset sequence of the Six Direction application. * 0: Normal Operation. * 1: Initiates the reset sequence of the GPIO Input/Output application. Not used. 23 * 0: Normal operation. Reset/Suspend/Clear * 1: Initiates the reset sequence of the Reset/Suspend/Clear application. 22 Reserved Not used. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 89 Configuration registers for Reset/Suspend/Clear Control applications Table 138. Reset bit descriptions (Continued) Field Description 21 Pedometer * 0: Normal operation. * 1: Initiates the reset sequence of the Pedometer application. 20:19 Reserved Not used. 18 Auto-Wake/Sleep * 0: Normal operation. * 1: Initiates the reset sequence of the Auto-Wake/Sleep application. 17 Reserved Not used. 16 Event-FIFO * 0: Normal operation. * 1: Initiates the reset sequence of the Event-Queue application. 15 Data FIFO * 0: Normal operation. * 1: Initiates the reset sequence of the Data FIFO application. 14:8 Reserved Reserved 7 Reserved Reserved 6 AFE * 0: Normal operation. * 1: Initiate the reset sequence of the front-end application. 5 Reserved Reserved 4 Mailbox * 0: Normal operation. * 1: Initiates the reset sequence of the mailbox application. 3 GPIO_AppMap * 0: Normal operation. * 1: Initiates the reset sequence of the GPIO AppMap application. 2 * 0: Normal operation. Command Interpreter * 1: Initiates the reset sequence of the command-interpreter application. 1 Scheduler * 0: Normal operation. * 1: Initiates the reset sequence of the scheduler-application. 0 General Reset 14.2.2 * 0: Normal operation. * 1: Initiates a system-wide reset sequence of all MMA9555Lapplications. Suspend configuration register Table 139. Suspend registers (MSB) 0x04 = reset_bits[31:24] Offset Bit 31 30 28 27 Reserved Field Reset 29 1 1 1 1 1 26 25 24 Six Direction GPIO Input/ Output Reserved 1 1 1 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 90 Freescale Semiconductor, Inc. Configuration registers for Reset/Suspend/Clear Control applications Table 139. Suspend registers (Continued) 0x05 = reset_bits[23:16] Offset Bit 23 22 21 Field Rst/Susp/Clr Reserved Pedometer Reset 0 1 1 20 19 Reserved 1 18 17 16 Auto-Wake/ Sleep Status Event FIFO 1 1 1 10 9 8 1 1 1 1 0x06 = reset_bits[15:8] Offset Bit 15 14 13 Field Data FIFO Frame Counter Reset 1 1 12 11 Reserved 1 1 1 (LSB) 0x07 = reset_bits[7:0] Offset Bit 7 6 5 4 3 2 1 0 Field Reserved AFE Reserved MBOX GPIO CI Scheduler General Susp Reset 1 1 1 1 1 1 1 1 Table 140. Suspend bit descriptions Field 31:27 Reserved 26 Six Direction 25 GPIO Input/Output 24 Reserved Description Not used. * 0: Normal Operation * 1: Suspend the Six Direction application. * 0: Normal Operation * 1: Suspend the GPIO Input/output application. Not used. 23 * 0: Normal operation. Reset/Suspend/Clear * 1: Initiates the suspend sequence of the Reset/Suspend/Clear application. 22 Reserved 21 Pedometer 20:19 Reserved 18 Auto-Wake/Sleep 17 Reserved 16 Event-FIFO Not used. * 0: Normal operation. * 1: Suspend the Pedometer application. Not used. * 0: Normal Operation * 1: Initiates the suspend sequence of the Auto-Wake/Sleep application. Not used. * 0: Normal Operation * 1: Initiates the suspend sequence of the Event-Queue application. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 91 Configuration registers for Reset/Suspend/Clear Control applications Table 140. Suspend bit descriptions (Continued) Field Description 15 Data FIFO * 0: Normal operation. * 1: Initiates the suspend sequence of the Data FIFO application. 14:8 Reserved * Reserved 6 AFE * 0: Normal Operation * 1: Initiate the suspend sequence of the front-end application. 5 Reserved Reserved. 4 Mailbox * 0: Normal Operation * 1: Initiates the suspend sequence of the mailbox application. 3 GPIO AppMap * 0: Normal Operation * 1: Initiates the suspend sequence of the GPIO AppMap application. 2 * 0: Normal Operation Command Interpreter * 1: Initiates the suspend sequence of the command-interpreter application. 1 Scheduler * 0: Normal Operation * 1: Initiates the suspend sequence of the scheduler-application. 0 General Suspend 14.2.3 * 0: Normal Operation * 1: Initiates a system-wide suspend sequence of all MMA9555Lapplications. Clear configuration register Table 141. Clear registers (MSB) 0x08 = reset_bits[31:24] Offset Bit 31 30 28 27 Reserved Field Reset 29 1 1 1 1 26 25 24 Six Direction GPIO Input/ Output Reserved 1 1 1 18 17 16 AutoWake/ Sleep Status Event FIFO 1 1 1 10 9 8 1 1 1 0x09 = reset_bits[23:16] Offset Bit 23 22 21 Field Rst/Susp/Clr Reserved Pedometer Reset 0 1 1 20 19 Reserved 1 1 0x10 = reset_bits[15:8] Offset Bit 15 14 Field Data FIFO Frame Counter Reset 1 1 13 12 11 Reserved 1 1 1 1 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 92 Freescale Semiconductor, Inc. Configuration registers for Reset/Suspend/Clear Control applications Table 141. Clear registers (Continued) (LSB) 0x11 = reset_bits[7:0] Offset Bit 7 6 5 4 3 2 1 0 Field Reserved AFE Reserved MBOX GPIO CI Scheduler General Clear Reset 1 1 1 1 1 1 1 1 Table 142. Clear bit descriptions Field 31:27 Reserved 26 Six Direction 25 GPIO Input/Output 24 Reserved Description Not used. * 0: Normal Operation * 1: Clear the Six Direction application * 0: Normal Operation * 1: Clear the GPIO Input/output application Not used. 23 * 0: Normal operation. Reset/Suspend/Clear * 1: Clear the Reset/Suspend/Clear application. 22 Reserved 21 Pedometer 20:19 Reserved 18 Auto-Wake/Sleep 17 Reserved Not used. * 0: Normal operation. * 1: Clear sequence of the Pedometer application. Not used. * 0: Normal Operation * 1: Clear the Auto-Wake/Sleep application. Not used. 16 Event-FIFO * 0: Normal Operation * 1: Clear the Event-Queue application. 15 Data FIFO * 0: Normal operation. * 1: Clear the Data FIFO application. 14:8 Reserved Reserved. 7 AFE Reserved. 6 AFE * 0: Normal Operation * 1: Clear the front-end application. 5 Reserved 4 Mailbox Reserved. * 0: Normal Operation * 1: Clear the mailbox application. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 93 Reset/Suspend/Clear status registers Table 142. Clear bit descriptions (Continued) Field 3 GPIO AppMap Description * 0: Normal Operation * 1: Clear the GPIO AppMap application. 2 * 0: Normal Operation Command Interpreter * 1: Clear the command-interpreter application. 1 Scheduler 0 General Clear * 0: Normal Operation * 1: Clear the scheduler-application. * 0: Normal Operation * 1: Clear all MMA9555L applications. Once an application has set a flag, it can be reset by one of the following mechanisms: * Execute a power-on reset. * Wake the device after a low-power mode. * Direct the host to write to general, reset/suspend/clear configuration bit. * Direct the host to write to an application reset/suspend/clear configuration bit. 14.3 Reset/Suspend/Clear status registers There are no status registers. 14.4 Reboot to ROM CI from flash code In order to reboot to ROM Command Interpreter, it is necessary to execute the reset callback function of the reset/suspend/clear application by setting the respective reset flag. The complete command for this operation is: Example 16. MBOX0 MBOX1 MBOX2 MBOX3 MBOX4 14.5 = = = = = 0x17 0x20 0x01 0x01 0x80 /*Application ID*/ /*CONFIG_W command*/ /*Offset*/ /*Number of bytes to write*/ /*Data*/ Reboot to flash code from ROM CI The operation to reboot into flash code when the ROM Command Interpreter is running can be performed by sending a CI_RESET command, the mailbox settings for this command is: Example 17. MBOX0 MBOX1 MBOX2 MBOX3 MBOX4 MBOX5 = = = = = = 0x29 0x00 0xFF 0xFF 0xFF 0xFF /*ROM Command for boot to flash*/ /*Reserved*/ /*CI_PWR*/ /*CI_PWR*/ /*CI_PWR*/ /*CI_PWR*/ For details about the ROM CI commands, see the MMA955xL Intelligent, Motion-Sensing Platform Hardware Reference Manual (MMA955xLHWRM), listed in "Related Documentation" on page 2. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 94 Freescale Semiconductor, Inc. 15 MBOX Configuration Application 15.1 Overview of MBOX Configuration application The MBOX Configuration application works with the Mailbox application (Chapter 8, "Mailbox Application") and the Communications application (Chapter 4, "Communication Interface") to provide data back to the host in a way that the host can best use the data. The MBOX Configuration application configures how the mailboxes behave. The Mailbox application configures what data is stored in the mailboxes. By default, the MMA9555L operates in the Command/Response mode, where a host must issue a write command followed by one or more reads to get data. The MMA9555L can also be put into a Legacy mode, where the host just issues a read command to get data. Application ID 0x18 Default speed Always available. Configuration registers See page 97. Status registers None. The mailboxes can be accessed in either of two modes: Normal or Legacy. The mailboxes' default mode is Normal, but the mode can be changed through this the mailbox configuration application (APP_ID = 0x18). The following figure shows the differences between the Normal and Legacy modes. Address Normal Mode Legacy Mode 0 Command / Response mailboxes ... Command / Response mailboxes 19 20 Quick-Read mailboxes ... 31 Figure 21. Difference between Normal and Legacy modes 15.2 Normal mode In Normal mode, only the command/response communications model is supported. In order to read valid data from the MMA9555L, the host must send a command through the mailboxes and wait for the command to be processed. Then, the host must read back the mailboxes that now have the data. The host can wait for the command to be processed by polling the Command Complete (COCO) bit or the host can wait for the INT_O interrupt. The Normal mode fully supports streaming-read transactions when the response to a command may be more than 32 bytes long. The following procedure gives the sequence for setting up the interrupt pin to go active after a COCO: Example 18. 1. 2. 3. 4. 5. MB0: Set the "APP_ID: Communication application" (0x18) application identifier. MB1: Set the "Command: Write Config" (0x20) application identifier. MB2: Set the Offset to Zero field (0x00) to point to the configuration register. MB3: Set the Count field to (0x01). This is done because only one data byte needs to be sent. MB4: Set the DATA (0x80) bit 7. This enables the interrupt pin. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 95 Legacy mode Bytes to Send: 0x18, 0x20, 0x00, 0x01, 0x80. 15.3 Legacy mode In Legacy mode, the lower-address mailboxes operate as described in the Normal mode--in the command/response communications model. MB20 through MB31, however, are used as Quick-Read registers. These registers are automatically updated at the end of each sample frame with the latest results from the chosen applications. The Mailbox application determines what data will appear in the mailboxes. The quick-read output data is selected with the configuration of the Mailbox application. (For more detail, see "Mailbox Application" on page 41.) Quick-Read registers enable the host to quickly and directly read a limited set of data directly from the MMA9555L without first having to issue a command and wait for the completion of the command processing. This makes support easier for legacy systems that expect to read sensor data. (In Legacy mode, MB20 to MB31 are reserved for mapping the Quick-Read registers.) By default, the Quick-Read registers (MB20-MB31) contain the following data: MB20-MB21 = Status 0,1 MB22 = Event Queue status MB23 = FIFO status MB24-MB25 = AFE Frame Counter MB26-MB27 = AFE, Stage 0; X-axis data MB28-MB29 = AFE, Stage 0; Y-axis data MB30-MB31 = AFE, Stage 0; Z-axis data This data--in the Quick-Read registers in Legacy mode--can be changed with the Mailbox application. 15.4 Configuring mailbox operational mode The operational mode of the slave communications interface mailbox is configured via the Mailbox Configuration application. This application allows the host system to configure the slave communications interface functions including the mailbox transaction interrupt pin mode, mailbox Normal/Legacy modes, and transaction-streaming modes. The following example shows how to configure the mailbox operating mode from Normal to Legacy Example 19. 1. 2. 3. 4. 5. MB0: Set the "APP_ID: Mailbox Mode Config" application identifier (0x18). MB1: Set the "Command: Write Config" application identifier (0x20). MB2: Set the Offset to Zero field (0x00) to point to the configuration register. MB3: Set the Count field to 0x01 because only one data byte needs to be sent. MB4: Set the DATA value to 0x10. This sets the Legacy field to 1b which selects the Legacy mode. Bytes to send: 0x18, 0x20, 0x00, 0x01, 0x10. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 96 Freescale Semiconductor, Inc. MBOX Configuration memory map and register 15.5 MBOX Configuration memory map and register 15.5.1 MBOX Configuration memory map Table 143. memory map Offset address Register 0x00 15.5.2 MBOX Configuration register Access Reset Details Read/Write 0x00 Section 15.5.2 MBOX Configuration register Table 144. MBOX Configuration register 0x00 Offset Bit 7 6 5 4 Field INT_O_EN INT_O_POL INT_O_ FRAME_EN LEGACY Reset 0 0 0 0 3 2 1 0 UPDMODES -- -- 00 0 0 Table 145. Communications configuration register field descriptions Field 7 INT_O_EN 6 INT_O_POL 5 INT_O_FRAME_EN Description Enables or disables the assertion of the INT_O signal every time a mailbox command is been processed. Range of valid values: 0 Disables the assertion of the INT_O signal. 1 Enables the assertion of the INT_O signal. Configures the polarity of the INT_O signal when it is asserted. Range of valid values: 0 Active high. 1 Active low. If enabled, generates the INT_O interrupt on completion of the AFE sample--once each frame. If not enabled, the INT_O signal is generated on a command-complete basis. This bit was added to support synchronization between the host and the MMA9555L device. Data will be ready on a frame basis. Range of valid values: 0: Interrupt not generated. 1: Interrupt generated on completion of AFE sample. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 97 MBOX Configuration memory map and register Table 145. Communications configuration register field descriptions (Continued) Field 4 LEGACY 3 UPDMODES 1:0 Reserved Description Selects between Normal and Legacy mode. Range of valid values: 0: Normal mode. 1: Legacy mode. When in Legacy mode, configures how and when the Quick-Read registers are updated. This field is valid only if the Mailbox is operating in Legacy mode. See Bit 4. Range of valid values: 00 Mode 0: Updates the Quick-Read registers (QR) whether the slave port is active or inactive. 01 Mode 1: Updates the QR registers only if the slave port is inactive. If the slave port is active, the update takes no action and waits until the slave port is inactive. 10 Mode 2: Updates the QR registers if the slave port is inactive. If the slave port is active (I2C transactions are running), this mode will enable a receive interrupt in the slave port to be triggered immediately after the transaction ends. After this, the QR register is immediately updated and the receive interrupt disabled. Reserved. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 98 Freescale Semiconductor, Inc. 16 Pedometer Application 16.1 Background and overview The MMA9555L's major application is the pedometer.The pedometer has calculations for step-counting, speed, distance, activity-monitoring, and calorie-counting, as well as autonomous sleep functionality to minimize current consumption. The following figure illustrates the hardware and software components and interactions in the MMA9555L. Application ID 0x15 Default speed 30 Hz. Configuration registers Start on page 104. Status registers Start on page 108. Platform Host processor Device MMA9555L firmware Analog Front End Analog Front End application Slave port Command Interpreter RGPIO RGPIO application Pedometer firmware Figure 22. Pedometer Data Flow Diagram 16.2 Functional description 16.2.1 Step detection Step detection is based solely on detecting step impact, without taking into consideration the consumer's height, weight, or gender. The algorithm operates by keeping track of momentary acceleration, defined as: A = 2 2 X +Y +Z 2 where X, Y, and Z represent a single accelerometer reading, normalized by dividing by 1 g. The values of A are accumulated over a fixed period of time (0.19 seconds). At every reading, the average A for that period is calculated and saved. The algorithm detects steps by analyzing the spread of the accumulated average A values. The spread is the difference between minimum and maximum of the calculated values. For a step to be reported, the spread in the buffer of average values of A has to exceed a fixed threshold (0.13 g) and stay above that threshold for at least the fixed value of 0.07 seconds. If the spread falls below the threshold sooner than 0.07 seconds, the motion is ignored. The STEPCNT variable contains the number of steps detected since the last reset. That count is updated every time a step is detected. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 99 Functional description 16.2.2 Distance estimation The distance estimation begins with the Base Stride Length (BSL), the estimated stride length for this consumer. The BSL is calculated as follows: BSL = Height ( centimeters ) x GenderFactor x 1.1 where Height is the consumer's height and GenderFactor is 0.415 for males or 0.413 for females. For more information about Height, see "Height/Weight register" on page 106. For more information on GenderFactor, see "Filter register" on page 106. If no consumer information is provided, BSL is set to 0, and the resulting distance values are 0. If there is a need to update the BSL without consumer information, the configuration structure can be used to set a fixed stride length. The estimated stride length is calculated by adjusting the BSL for step rate (steps/second). Stride length for a particular step is calculated as follows: Stride = BSL x StepRateFactor The StepRateFactor values are shown in the following table: Table 146. StepRateFactor calculation Step rate, S (steps/sec) StepRateFactor S < 1.6 (very slow) 0.88 1.8 S < 2.35 (normal) 1.00 1.6 S < 1.8 (slow) 2.35 S < 2.8 (fast) S 2.8 (very fast) 0.95 1.30 2.30 The overall distance is calculated as the sum of estimated stride lengths for all steps detected since the last reset. The DISTANCE variable contains the value of overall distance and is updated every time a step is detected. 16.2.3 Speed calculation Speed is calculated over a sliding time window as: Distance (meters) Speed = -------------------------------------------Time where Distance is the total distance covered by all steps detected within the time window. Time is the length of the window and can be configured by the SPDPRD variable. For more information, see: * Speed: "Speed register" on page 110 * Distance: "Distance register" on page 110 * Time: "Filter register" on page 106 * SPDPRD variable: "Speed Period/Step Threshold register" on page 107 The SPEED variable contains the current speed value and is updated every time a step is detected or once per second if there are no steps. If there are no steps, the speed may not necessarily fall to zero even if the activity level, which is described in the following section, falls to Rest. The activity level is reset to Rest if there are no steps for a certain amount of time. The speed calculation does not include a similar reset when there are no steps. Therefore, it may conflict with the activity level. In this scenario, the user should disregard the speed if the activity level is Rest. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 100 Freescale Semiconductor, Inc. Functional description 16.2.4 Activity-level calculation The activity-level calculation is based on the speed value. The activity-level value is assigned according to the following table. Table 147. Activity-level calculation Latest speed, S (Km/h) Activity level S 10.5 Running 6.5 S < 10.5 Jogging 1.0 S < 6.5 Walking S < 1.0 Rest The ACTIVITY variable contains the current activity level and is updated every time a step is detected or once per second if there are no steps. Additionally, if no steps are detected for the previous 2.5 seconds, the activity level is reset to Rest. 16.2.5 Calorie-expenditure calculation The estimated amount of calories burned by a single step is calculated as: MetabolicFactor x 0.00029 Calories = ---------------------------------------------------------------------- x Weight StepRate where StepRate is calculated as described in "Distance estimation" on page 100, Weight is the consumer's weight in kilograms, and MetabolicFactor is calculated according to the following table: Table 148. MetabolicFactor calculation Step Rate, S (steps/sec) MetabolicFactor S < 1.6 (very slow) 2.0 1.6 S < 1.8 (slow) 1.8 S < 2.35 (normal) 2.35 S < 2.8 (fast) S 2.8 (very fast) 2.5 3.8 8.0 12.5 For more information, see: -- StepRate: "Filter register" on page 106 -- Weight: "Height/Weight register" on page 106 The CALS variable contains the total amount of calories burned since the last reset. The value is updated every time a step is detected. 16.2.6 Debounce count The debounce_count() function implements a debounce counter as defined in application note Motion and Free fall Detection Using the MMA8450Q (AN3917), listed in "Related Documentation" on page 2. If the input condition is satisfied, the count is incremented by one up to the threshold. Otherwise, the count is decremented or cleared depending on the debounce counter mode. The debounce counter's behavior is shown in Figure 23. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 101 Functional description Low-g event on all three axes (Freefall) (a) Count threshold FF_MT counter value EA FF Low-g event on all three axes (Freefall) DBCNTM = 1 Count threshold (b) FF_MT counter value EA FF Low-g event on all three axes (Freefall) DBCNTM = 0 Count threshold (c) FF_MT counter value EA FF Figure 23. Debounce counter behavior 16.2.7 Autonomous suspend The pedometer uses the acceleration vector magnitude squared, (X2 + Y2 + Z2), to determine if the device is stationary. It is designed to suspend the pedometer conservatively and wake the pedometer aggressively to avoid missing any steps. The autonomous-suspend function compares the acceleration vector magnitude to the configurable minimum and maximum thresholds (SLEEPMIN and SLEEPMAX) and passes the boolean result to a debounce counter. If the thresholds are satisfied for at least SLEEPTHD samples, the pedometer autonomously suspends. The thresholds are satisfied if the output of the debounce counter is asserted. If the thresholds are not satisfied for at least SLEEPTHD samples, the pedometer executes normally. The parameters SLEEPMIN, SLEEPMAX, SLEEPTHD, and SLP_DBCNTM configure the behavior. The SLEEPMAX parameter's reset value disables the autonomous suspend function by default. For more information, see: * SLEEPMIN: "Sleep Minimum register" on page 104 * SLEEPMAX: "Sleep Maximum register" on page 104 * SLEEPTHD: "Sleep Count Threshold register" on page 105 * SLP_DBCNTM: "Configuration/Step Length register" on page 105 If custom sleep functionality is desired, a user may disable the pedometer's autonomous-suspend functionality and instead use the MMA9555L's Reset/Suspend/Clear application to enable or disable the pedometer. For an example, see "Enable/disable the Pedometer application" on page 124. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 102 Freescale Semiconductor, Inc. Memory-maps and register descriptions 16.3 Memory-maps and register descriptions The Pedometer Application running in the MMA9553L device has eight configuration registers and six status or data registers. The configuration registers allow the user to customize and control the behavior of the pedometer application. The status registers report back the measured and calculated data. All status registers are shown as 16-bits wide. They are byte-accessible, but should be read 16 bits (two bytes) or more at a time with a single command, if the user wishes to read them atomically. Similarly, configuration registers are shown as 16-bits wide but are also byte-accessible. Most fields defined within the configuration registers are 8-bits or less and are byte-aligned, so they can be written one byte at a time if desired. All bytes should be written using a single command if the user wishes to modify them atomically. 16.3.1 Pedometer memory maps Table 149. Configuration registers Offset address Register Access Reset Details 0x0 Sleep Minimum register R/W 0x0000 "Sleep Minimum register" on page 104 0x2 Sleep Maximum register R/W 0x0000 "Sleep Maximum register" on page 104 0x4 Sleep Count Threshold register R/W 0x0001 "Sleep Count Threshold register" on page 105 0x6 Config/Step Length register R/W 0x0000 "Configuration/Step Length register" on page 105 0x8 Height/Weight register R/W 0xAF50 "Height/Weight register" on page 106 0xA Filter register R/W 0x0403 "Filter register" on page 106 0xC Speed Period register R/W 0x0582 "Speed Period/Step Threshold register" on page 107 0xE Activity Count Threshold register R/W 0x0000 "Activity Count Threshold register" on page 107 0xF Step Coalesce register R/W 0x01 "Step Coalesce register" on page 107 Table 150. Status registers Offset address Register Access Reset Details 0x0 Status register R 0x0002 "Status register" on page 108 0x2 Step count register R 0x0000 "Step Count register" on page 109 0x4 Distance register R 0x0000 "Distance register" on page 110 0x6 Speed register R 0x0000 "Speed register" on page 110 0x8 Calories register R 0x0000 "Calories register" on page 110 0xA Sleep Count register R 0x0000 "Sleep Count register" on page 111 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 103 Memory-maps and register descriptions 16.3.2 Pedometer configuration-register descriptions 16.3.2.1 Sleep Minimum register Table 151. Sleep Minimum register 15 Bit 14 13 12 11 10 9 Read 8 7 6 5 4 3 2 1 0 SLEEPMIN Write 0x0000 Reset Table 152. Sleep Minimum register field descriptions Field Description 15:0 SLEEPMIN Minimum acceleration vector magnitude for autonomous suspend. The acceleration vector magnitude must be greater than SLEEPMIN and less than SLEEPMAX to satisfy the autonomous suspend condition(1). At rest, the acceleration vector magnitude measures approximately 1 g. Therefore, SLEEPMIN and SLEEPMAX are expected to be set to values near 1 g (4096 at 0.244 mg/LSB resolution). Valid range: 0x0000:0xFFFF (uint16). Units: 0.244 mg/LSB 1. This condition must be satisfied for SLEEPTHD samples for the pedometer to autonomously suspend. See Table 156 on page 105. 16.3.2.2 Sleep Maximum register Table 153. Sleep Maximum register 15 Bit Read Write Reset 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SLEEPMAX 0x0000 Table 154. Sleep Maximum register field descriptions 1. Field Description 15:0 SLEEPMAX Maximum acceleration vector magnitude for autonomous suspend. The acceleration vector magnitude must be greater than SLEEPMIN and less than SLEEPMAX to satisfy the autonomous suspend condition(1). At rest, the acceleration vector magnitude measures approximately 1 g. Therefore, SLEEPMIN and SLEEPMAX are expected to be set to values near 1 g (4096 at 0.244 mg/LSB resolution). Set to SLEEPMAX 0 to disable autonomous suspend. Valid range: 0x0000:0xFFFF (uint16). Units: 0.244 mg/LSB This condition must be satisfied for SLEEPTHD samples for the pedometer to autonomously suspend. See Table 156 on page 105. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 104 Freescale Semiconductor, Inc. Memory-maps and register descriptions 16.3.2.3 Sleep Count Threshold register Table 155. Sleep Count Threshold register 15 Bit 14 13 12 11 10 9 Read 8 7 6 5 4 3 2 1 0 SLEEPTHD Write 0x0001 Reset Table 156. Sleep Count Threshold register field descriptions 1. Field Description 15:0 SLEEPTHD Autonomous suspend debounce count threshold. The autonomous suspend condition(1) must be satisfied for SLEEPTHD samples for the pedometer to autonomously suspend. Valid range: 0x0000:0xFFFF (uint16). The acceleration vector magnitude must be greater than SLEEPMIN and less than SLEEPMAX to satisfy this condition. For more information on SLEEPMIN and SLEEPMAX, see "Sleep Minimum register" and "Sleep Maximum register". 16.3.2.4 Configuration/Step Length register 14 13 0 0 Read Write Reset 12 11 10 9 8 7 6 5 4 3 SLP_DBCNTM 15 ACT_DBCNTM Bit CONFIG Table 157. Configuration/Step Length register -- STEPLEN 0 00000 0x00 2 1 0 = Unimplemented or reserved Table 158. Configuration/Step Length register field descriptions Field 15 CONFIG Description (Re)initializes the pedometer with current configuration values. Modifications to other pedometer configuration registers will not take effect until this bit is set. It is automatically cleared after the (re)initialization completes. 0: Do not (re)initialize the pedometer 1: (Re)initialize the pedometer with current configuration values 14 ACT_DBCNTM Activity debounce counter mode. 0: Decrement the count when the activity level changes 1: Clear the count when the activity level changes 13 SLP_DBCNTM Autonomous suspend debounce counter mode. 0: Decrement the count when the device is in motion 1: Clear the count when the device is in motion 12:8 -- 7:0 STEPLEN Reserved. Set to 0. Step length in centimeters. Set to 0 to automatically estimate the consumer's step length based on gender and height. Valid range: 0x00:0xFF (uint8) MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 105 Memory-maps and register descriptions 16.3.2.5 Height/Weight register Table 159. Height/Weight register 15 Bit 14 13 Read Write Reset 12 11 10 9 8 7 6 5 4 3 HEIGHT WEIGHT 0xAF 0x50 2 1 0 2 1 0 Table 160. Height/Weight register field descriptions Field Description 15:8 HEIGHT Height in centimeters. Used to estimate step length, if STEPLEN = 0. Valid range: 0x00:0xFF (uint8) Default = 0xAF (175 centimeters). 7:0 WEIGHT Weight in kilograms. Used to estimate step length, if STEPLEN = 0. Valid range: 0x00:0xFF (uint8) Default = 0x50 (80 kilograms). 16.3.2.6 Filter register Table 161. Filter register 15 Bit 14 13 Read Write Reset 12 11 10 9 8 7 6 5 4 3 FILTSTEP MALE FILTTIME 0x04 0 0x03 Table 162. Filter register field descriptions Field Description 15:8 FILTSTEP Number of steps that must occur within FILTTIME for the pedometer to decide the consumer is making steps. Set to 0 to disable step filtering. If the value specified is greater than 6, then 6 will be used. Valid range: 0x00:0x06 (uint8). Default = 0x04. 7 MALE 6:0 FILTTIME Gender 0: Female 1: Male Number of seconds in which filter steps must occur. Set to 0 to disable step filtering. Valid range: 0x00:0x7F (uint8) Default = 0x03. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 106 Freescale Semiconductor, Inc. Memory-maps and register descriptions 16.3.2.7 Speed Period/Step Threshold register Table 163. Speed Period register 15 Bit 14 13 Read Write 12 11 10 9 8 7 6 5 4 3 2 SPDPRD STEPTHRESHOLD 0x05 0x82 Reset 1 0 Table 164. Speed Period/Step Threshold register field descriptions Field Description Number of seconds in which to compute speed. If set to a value greater than 5, then 5 will be used. Valid range: 0x02:0x05. Warning: Do not set SPDPRD to 0 or 1 as this may cause undesirable behavior. 15:8 SPDPRD 7:0 STEPTHRESHOLD 16.3.2.8 Magnitude acceleration threshold to detect a step. Large values make the pedometer less sensitive; small values make the pedometer more sensitive and may lead to false positives. Units: 1 mg/LSB Valid range: 0x00:0xFF (uint8) Default: 0x82 (0.13 g) Activity Count Threshold register Table 165. Activity Count Threshold register 15 Bit 14 13 12 11 10 9 8 Read 7 6 5 4 3 2 1 0 ACTTHD Write 0x0000 Reset Table 166. Activity Count Threshold register field descriptions Field 15:0 ACTTHD 1. Description Activity debounce count threshold. The internal activity level must be stable for ACTTHD samples before ACTIVITY is updated. Valid range: 0x0000:0xFFFF (uint16) 0: The activity debouncer is effectively bypassed.(1) 1: The current internal activity level must equal the previous internal activity level in order to update ACTIVITY. For more information on the activity debouncer, see Table 158 on page 105. 16.3.2.9 Step Coalesce register Table 167. Step Coalesce register Bit 7 Read Write Reset 6 5 4 3 2 1 0 STEPCOALESCE 0X01 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 107 Memory-maps and register descriptions Table 168. Activity Count Threshold register field descriptions Field Description 7:0 STEPCOALESCE 16.3.3 Number of steps to coalesce before asserting STEPCHG. 0: Disables STEPCHG. 1: Asserts STEPCHG after every step. The default. Valid range: 0x00:0xFF (uint8). Pedometer status-register descriptions Bit 15 14 13 12 Read MRGFL SUSPCHG STEPCHG ACTCHG SUSP ACTIVITY Table 169. Status register 11 10 9 8 7 6 5 4 3 VERSION 0 0 0 0 0 000 0x02 2 1 0 Write Reset = Unimplemented or reserved 16.3.3.1 Status register Table 170. Status register field descriptions Field Description 15 MRGFL Merged status change flags. This bit is the logical OR of the SUSPCHG, STEPCHG, and ACTCHG flags. It can be routed to a pin to enable a single, merged-output interrupt using the MMA955xL GPIO application(1). The host can trigger an interrupt on rising edges to receive notification when at least one of the status change flags is asserted. The host is responsible for resolving the source if desired. That can be done by comparing the STEPCNT to a previous value to determine that a STEPCNT change caused the MRGFL assertion. 0: None of the status change flags are asserted 1: At least one of the status change flags (SUSPCHG, STEPCHG, ACTCHG) is asserted 14 SUSPCHG Indicates a change in the SUSP bit. This bit is transient and only asserts during frames in which the SUSP bit changes from the previous frame. A frame is one 30-Hz period. This bit can be routed to a pin to enable output interrupts using the MMA9555L GPIO AppMap application(1). The host can trigger an interrupt on rising edges to receive notification when the pedometer suspends or resumes. 0: No change in the SUSP bit since the last pedometer call. 1: The SUSP bit changed since the last pedometer call. 13 STEPCHG Indicates a change in STEPCNT by STEPCOALSCE steps. This bit is transient and only asserts during frames in which STEPCNT changed from the previous frame. A frame is one 30-Hz period. This bit can be routed to a pin to enable output interrupts using the MMA9555L GPIO AppMap application(1). The host can trigger an interrupt on rising edges to receive notification after every step. 0: The step count has not been incremented by STEPCOALESCE steps since the last STEPCHG assertion or the pedometer was last initialized. 1: The step count has been incremented by STEPCOALESCE steps since the last STEPCHG assertion or the pedometer was last initialized. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 108 Freescale Semiconductor, Inc. Memory-maps and register descriptions Table 170. Status register field descriptions 1. Field Description 12 ACTCHG Indicates a change in activity level. This bit is transient and only asserts during frames in which ACTIVITY changed from the previous frame. A frame is one 30-Hz period. This bit can be routed to a pin to enable output interrupts using the MMA9555L GPIO AppMap application(1). The host can trigger an interrupt on rising edges to receive notification when the activity level is changed. 0: No change in activity level since last pedometer call 1: New activity level since last pedometer call 11 SUSP Indicates whether the pedometer is active or has been autonomously suspended. This bit can be routed to a pin to enable output interrupts using the MMA9555L GPIO AppMap application(1). The host can trigger an interrupt on rising edges to receive notification when the pedometer is autonomously suspended and trigger an interrupt on falling edges to receive notification when the pedometer resumes. 0: Pedometer is active 1: Pedometer is suspended 10:8 ACTIVITY Activity level: 000: Unknown 001: Rest 010: Walking 011: Jogging 100: Running 101-111: Reserved 7:0 VERSION Version number of the pedometer application, incremented by one for each new release. 0: R1.32 1: R1.33 2: R1.34 For more information on the GPIO AppMap application, see Chapter 7, "GPIO-AppMap Application". 16.3.3.2 Step Count register Table 171. Step Count register Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 STEPCNT Read Write 0x0000 Reset = Unimplemented or reserved Table 172. Step Count register field descriptions Field 15:0 STEPCNT Description The total step count since the pedometer was last reset. Valid range: 0x0000:0xFFFF (uint16) MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 109 Memory-maps and register descriptions 16.3.3.3 Distance register Table 173. Distance register 15 Bit 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 DIST Read Write 0x0000 Reset = Unimplemented or reserved Table 174. Distance register field descriptions Field 15:0 DIST 16.3.3.4 Description The total distance in meters since the pedometer was last reset. Valid range: 0x0000:0xFFFF (uint16). Speed register If there are no steps, the speed may not necessarily fall to zero even if the activity level falls to rest. See 16.2.3, "Speed calculation" on page 100 for more information. Table 175. Speed register 15 Bit 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 4 3 2 1 0 SPEED Read Write 0x0000 Reset = Unimplemented or reserved Table 176. Speed register field descriptions Field 15:0 SPEED 1. Description Average speed in meters per hour over SPDPRD(1). Valid range: 0x0000:0xFFFF (uint16) For information on SPDPRD, see Table 164 on page 107. 16.3.3.5 Calories register Table 177. Calories register Bit 15 14 13 12 11 10 9 8 7 6 5 CALS Read Write 0x0000 Reset = Unimplemented or reserved MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 110 Freescale Semiconductor, Inc. Pedometer application examples Table 178. Calories register field descriptions Field Description 15:0 CALS Total calorie count since the pedometer was last reset. Valid range: 0x0000:0xFFFF (uint16) 16.3.3.6 Sleep Count register Table 179. Sleep Count register 15 Bit 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 SLEEPCNT Read Write 0x0000 Reset = Unimplemented or reserved Table 180. Sleep Count register field descriptions Field Description 15:0 SLEEPCNT 16.4 16.4.1 Current value of the autonomous suspend debounce counter. Valid range: 0x0000:0xFFFF (uint16) Pedometer application examples Pedometer application configuration example To write all the pedometer configuration registers, the following command packet shall be sent from the host to the device mailboxes. The most significant byte of a register (MSB) is written in the lowest-numbered mailbox. NOTE The question marks represent placeholders for the application specific values. Please replace the question marks with values for the application. MB0 = 0x15: Set the Pedometer Application Identifier (0x15) MB1 = 0x20: Set the Command: Write Config command, with zero offset (0x20) MB2 = 0x00: Set the Offset to point to the first configuration register MB3 = 0x11: Set the Count field to declare writing 17 bytes MB4-MB5 = 0x????: Value for Sleep Min Register MB6-MB7 = 0x????: Value for Sleep Max Register MB8-MB9 = 0x????: Value for Sleep Count Threshold MB10-MB11 = 0x????: Value for Config / Step Length Register MB12-MB13 = 0x????: Value for Height / Weight MB14-MB15 = 0x????: Set the Filter Register MB16-17 = 0x????: Set the Speed Period / Step Threshold Register MB18-19 = 0x????: Set the Activity Count MB20 = 0x??: Set the Step Coalesce Bytes to send: 0x15, 0x20, 0x00, 0x11, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x?? MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 111 Pedometer application examples To read all the pedometer configuration registers, send the following command packet from the host to the device mailboxes. This can be used as a device identification command, allowing a host to differentiate the MMA9555L from the MMA955xL. MB0: 0x15 = pedometer application ID MB1: 0x10 = opcode to read configuration MB2: 0x00 = offset into pedometer configuration register map MB3: 0x11 = number of bytes to read The MMA9555L response will be: MB0: 0x15 = pedometer application ID MB1: 0x80 = COCO=1, error code=0 MB2: 0x11 = actual number of bytes read MB3: 0x11 = requested number of bytes to read MB4: sleep minimum MSB MB5: sleep minimum LSB MB6: sleep maximum MSB MB7: sleep maximum LSB MB8: sleep count threshold MSB MB9: sleep count threshold LSB MB10: config MB11: step length MB12: height MB13: weight MB14: filter step MB15: male, filter time MB16: speed period MB17: step threshold MB18: activity count threshold MSB MB19: activity count threshold LSB MB20: step coalesce MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 112 Freescale Semiconductor, Inc. Pedometer application examples 16.4.2 Pedometer application read example To read all the pedometer status registers, send the following command packet from the host to the device mailboxes: MB0 = 0x15: Set the Pedometer Application Identifier (0x15) MB1 = 0x30: Set the Command: Read Status command, with zero offset (0x30) MB2 = 0x00: Set the Offset (0x00) to point to the first status register MB3 = 0x0C: Set the Count field to (12) to declare reading 12 bytes Read back the mailboxes, when the COCO (Command Complete) bit is set the status data will be in the mailbox registers. Bytes to send: 0x15, 0x30, 0x00, 0x0C The response to this command will be: MB0: 0x15 = pedometer application ID MB1: 0x80 = COCO=1, error code=0 MB2: 0x0C = actual number of bytes read MB3: 0x0C = requested number of bytes to read MB4: pedometer status register MSB MB5: pedometer status register LSB MB6: step count MSB MB7: step count LSB MB8: distance MSB MB9: distance LSB MB10: speed MSB MB11: speed LSB MB12: calories MSB MB13: calories LSB MB14: sleep count MSB MB15: sleep count LSB MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 113 17 GPIO Input/Output Application 17.1 Overview of GPIO Input/Output application Application ID The GPIO input/output application provides a function that can control seven physical GPIO Default speed pins of MMA9555L. It can set the direction GPIOs as input or output, control the pin level when the pin is set as an output pin and read the pin level through its status register. It also has a mask register, called the Enable Configuration Register, to avoid conflict with the GPIO Configuration AppMap application APP-ID 0x03. registers The GPIO pins that are available to this application are described in Table 181. Table 181. GPIO pin names, numbers and functions 17.2 Name Pin number GPIO2 7 GPIO3 8 GPIO4 9 GPIO5 11 GPIO6 12 GPIO7 13 GPIO8 15 GPIO9 2 Status registers 0x19 30 Hz. Start on page 115. Start on page 116. Memory maps and register descriptions The GPIO Input/Output Application has three configuration registers and one status register. The configuration registers allow the user to customize and control the behavior of the GPIO Input/Output application. The status registers report back the level of the GPIO2-GPIO9. The status register is 8 bits wide. Similarly, configuration registers are 8 bits wide. They can be written one byte at a time if desired. All bytes should be written using a single command if the user wishes to modify them atomically. 17.2.1 GPIO Input/Output memory maps Table 182. Configuration Registers Offset address Register Access Reset Details 0x00 GPIO input/output direction register R/W 0x0F "GPIO input/output direction register" on page 115 0x01 GPIO input/output enable register R/W 0x0F "GPIO input/output enable register" on page 115 0x02 GPIO input/output data register R/W 0x05 "GPIO input/output data register" on page 116 Table 183. Status register Offset address 0x00 Register GPIO input/output Status register Access Reset R 0x05 Details "GPIO Input/Output Status register" on page 116 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 114 GPIO Input/Output configuration register descriptions 17.3 GPIO Input/Output configuration register descriptions 17.3.1 GPIO input/output direction register Table 184. GPIO input/output direction register Bit 7 Read Write 6 5 4 3 2 1 0 DIR8 DIR7 DIR6 DIR5 DIR4 DIR3 DIR2 0x0F Reset = Unimplemented or reserved Table 185. GPIO input/output direction register field description Field Description 6:0 DIR8-DIR2 GPIO data direction. The value of this register is shifted and then copied to the hardware register RGPIO_DIR. 0: Configured as an input 1: Configured as an output 17.3.2 GPIO input/output enable register Table 186. GPIO input/output enable register Bit 7 Read Write 6 5 4 3 2 1 0 EN8 EN7 EN6 EN5 EN4 EN3 EN2 0x0F Reset = Unimplemented or reserved Table 187. GPIO input/output enable register description Field 6:0 EN8-EN2 Description GPIO enable. The value of this register is shifted and then copied to the hardware register RGPIO_EN. 0: Disable the pin in this application 1: Enable the pin in this application MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 115 GPIO Input/Output Status register descriptions 17.3.3 GPIO input/output data register Table 188. GPIO input/output data register 7 Bit Read Write 6 5 4 3 2 1 0 DATA8 DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 0x05 Reset = Unimplemented or reserved Table 189. GPIO input/output data register description Field Description 6:0 EN8-EN2 GPIO data output. The value of this register is shifted and then copied to the hardware register RGPIO_DATA. 0: Output low on the pin 1: Output high on the pin 17.4 GPIO Input/Output Status register descriptions 17.4.1 GPIO Input/Output Status register Table 190. GPIO input/output status register Bit Read Write 7 6 5 4 3 2 1 0 DATA9 DATA8 DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 0x05 Reset = Unimplemented or reserved Table 191. GPIO input/output status register description Field Description GPIO data output. The value of this register is read from hardware register RGPIO_DATA. 0: A properly enabled RGPIO output pin is driven with a logic 0, or a properly enabled RGPIO input pin was read 7:0 as a logic 0 DATA9-DATA2 1: A properly enabled RGPIO output pin is driven with a logic 1, or a properly enabled RGPIO input pin was read as a logic 1 NOTE Though GPIO9 cannot be set in the configuration registers, the pin level can be detected in the status register when GPIO9 is set as interrupt pin in APP-ID 0x03. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 116 Freescale Semiconductor, Inc. GPIO Input/Output application examples 17.5 17.5.1 GPIO Input/Output application examples GPIO Input/Output application configuration example To write all the GPIO Input/Output configuration registers, the following command packet should be sent from the host to the device mailboxes. The most significant byte of a register (MSB) is written in the lowest-numbered mailbox. NOTE The question marks represent placeholders for the application specific values. Please replace the question marks with the values for the application. MB0 : 0x19= Set the GPIO Input/Output Application Identifier (0x19) MB1 : 0x20= Set the Command: Write Config command, with zero offset (0x20) MB2 : 0x00= Set the Offset to point to the first configuration register MB3 : 0x03= Set the Count field to declare writing 3 bytes MB4 : 0x??= Value for GPIO input/output direction register MB5 : 0x??= Value for GPIO input/output enable register MB6 : 0x??= Value for GPIO input/output data register Bytes to send: 0x19, 0x20, 0x00, 0x03, 0x??, 0x??, 0x?? To read all the GPIO Input/Output configuration registers, the following command packet should be sent from the host to the device mailboxes. MB0: 0x19= GPIO Input/Output application ID MB1: 0x10= opcode to read configuration MB2: 0x00= offset into GPIO Input/Output configuration register map MB3: 0x03= number of bytes to read The MMA9555L response will be: MB0: 0x19 = GPIO Input/Output application ID MB1: 0x80 = COCO=1, error code=0 MB2: 0x03 = actual number of bytes read MB3: 0x03 = requested number of bytes to read MB4: Value of GPIO input/output direction register MB5: Value of GPIO input/output enable register MB6: Value of GPIO input/output data register 17.5.2 GPIO Input/Output application read example To read the GPIO Input/Output status register, the following command packet is sent from the host to the device mailboxes: MB0 : 0x19 = Set the GPIO Input/Output Application Identifier (0x19) MB1 : 0x30 = Set the Command: Read Status command, with zero offset (0x30) MB2 : 0x00 = Set the Offset (0x00) to point to the first status register MB3 : 0x01= Set the Count field to (1) to declare reading 1 byte Bytes to send: 0x19, 0x30, 0x00, 0x01 To read the mailboxes, when the COCO (Command Complete) bit is set, the status data are in the mailbox registers. The response to this command is: MB0: 0x19 = GPIO Input/Output application ID MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 117 GPIO Input/Output application examples MB1: 0x80 = COCO=1, error code=0 MB2: 0x01 = actual number of bytes read MB3: 0x01 = requested number of bytes to read MB4: GPIO input/output Status register MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 118 Freescale Semiconductor, Inc. 18 Six-Direction Application 18.1 Overview of the Six-Direction application Application ID The Six-Direction application detects six major directional orientations of the device in threeDefault speed dimensional space. It determines the primary axis that the device is oriented: +X, -X, +Y, -Y, +Z or -Z, with reference opposite to the direction of gravity. It uses the coordinate system as defined in Figure 5 on page 12. Configuration registers When the absolute g value of the current direction is less than half g, the application detects which axis has the largest absolute g value. If this axis is kept as the largest and the debounce count meets the count threshold, it updates the status of the direction. When the Status registers absolute g value of the current direction is larger than half g, it keeps current direction. 18.2 0x1A 30 Hz. Start on page 120. Start on page 121. Memory maps and register descriptions The Six-Direction Application running in the MMA9555L device has two configuration registers and two status registers. The configuration registers allow the user to customize and control the behavior of the Six-Direction application. The status registers report current direction status, status change flag and debounce count status. The status registers are 8 bits wide. They are byte-accessible, but should be read two bytes at a time with a single command, if the user wishes to read them atomically. Similarly, configuration registers are 8 bits wide. They can be written one byte at a time if desired. All bytes should be written using a single command if the user wishes to modify them atomically. 18.2.1 Six Direction register memory maps Table 192. Configuration registers Offset address Register Access Reset Details 0x00 SixDir Count Threshold register R/W 0x1E "SixDir Count Threshold register" on page 120 0x01 SixDir Debounce mode register R/W 0x01 "SixDir Debounce mode register" on page 120 Table 193. Status register Offset address Register Access Reset Details 0x00 SixDir Current Status register R/W 0x06 "SixDir Current Status register" on page 121 0x01 SixDir Debounce count register R/W 0x00 "SixDir Debounce count register" on page 121 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 119 Six Direction configuration register descriptions 18.3 Six Direction configuration register descriptions 18.3.1 SixDir Count Threshold register Table 194. SixDir Count Threshold register Bit 7 6 5 4 3 Read Write SDTHD Reset 0x30 2 1 0 = Unimplemented or reserved Table 195. SixDir Count Threshold register description Field 7:0 SDTHD 18.3.2 Description SixDir debounce count threshold. The status of the direction is not changed until the debounce count meets this threshold. Valid range: 0x00:0xFF (uint8). SixDir Debounce mode register Table 196. SixDir Debounce mode register Bit 7 6 5 4 3 2 Read Write 1 0 SDM 0x01 Reset = Unimplemented or reserved Table 197. SixDir Debounce mode register description Field 0 SDM Description SixDir debounce counter mode. 0: Decrement the count when the device changes direction 1: Clear the count when the device changes direction MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 120 Freescale Semiconductor, Inc. Six Direction Status register descriptions 18.4 Six Direction Status register descriptions 18.4.1 SixDir Current Status register Table 198. SixDir Current Status register Bit 7 Read Write SC_FLG 6 5 4 3 2 1 AXIS_POS 0 AXIS 0x06 Reset = Unimplemented or reserved Table 199. SixDir Current Status register description Field Description Direction Status change flag. 0: Direction has not changed 1: Direction changed. The bit is cleared when the register is read. 7 SC_FLG 2 AXIS_POS 1:0 AXIS 18.4.2 Sign of the direction of the axis detected 0 : Negative Direction 1: Positive direction Direction is on which axis. 00: X axis 01: Y axis 10: Z axis SixDir Debounce count register Table 200. SixDir Debounce count register Bit 7 6 5 4 3 Read Write SDCNT Reset 0x00 2 1 0 = Unimplemented or reserved Table 201. SixDir Debounce count register description Field 7:0 SDCNT 18.4.3 Description The total debounce count since the direction status was last reset. Valid range: 0x00:0xFF (uint8) Six Direction application configuration example To write all the Six-Direction configuration registers, the host should send the following command packet to the mailboxes. The most significant byte of a register (MSB) is written in the lower numbered mailbox. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 121 Six Direction Status register descriptions NOTE The question marks represent placeholders for the application-specific values. Please replace the question marks with the desired values for the application. MB0 : 0x1A= Set the Six-Direction Application Identifier (0x1A) MB1 : 0x20= Set the Command: Write Config command, with zero offset (0x20) MB2 : 0x00= Set the Offset to point to the first configuration register MB3 : 0x02= Set the Count field to declare writing 2 bytes MB4 : 0x??= Value for SixDir Count Threshold register MB5 : 0x??= Value for SixDir Debounce mode register Bytes to send: 0x1A, 0x20, 0x00, 0x02, 0x??, 0x?? To read all the Six-Direction configuration registers, the following command packet is sent from the host to the device mailboxes. MB0: 0x1A= Six-Direction application ID MB1: 0x10= opcode to read configuration MB2: 0x00= offset into Six-Direction configuration register map MB3: 0x02= number of bytes to read The MMA9555L response will be: MB0: 0x1A = Six-Direction application ID MB1: 0x80 = COCO=1, error code=0 MB2: 0x02 = actual number of bytes read MB3: 0x02 = requested number of bytes to read MB4: Value of SixDir Count Threshold register MB5: Value of SixDir Debounce mode register 18.4.4 Six Direction application read example To read the Six-Direction status register, the following command packet is sent from the host to the device mailboxes: MB0 : 0x1A = Set the Six-Direction Application Identifier (0x1A) MB1 : 0x30 = Set the Command: Read Status command, with zero offset (0x30) MB2 : 0x00 = Set the Offset (0x00) to point to the first status register MB3 : 0x02= Set the Count field to (2) to declare reading 2 bytes Bytes to send: 0x1A, 0x30, 0x00, 0x02 To read the mailboxes, when the COCO (Command Complete) bit is set, the status data is in the mailbox registers. The response to this command is: MB0: 0x1A= Six-Direction application ID MB1: 0x80 = COCO=1, error code=0 MB2: 0x02 = actual number of bytes read MB3: 0x02 = requested number of bytes to read MB4: Value of SixDir Current Status register MB5: Value of SixDir Debounce count register MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 122 Freescale Semiconductor, Inc. 19 Sample operations This section provides sample slave-port commands to read and modify application variables. 19.1 Read pedometer status variables This command reads all 12 bytes of the status variables from the Pedometer application (APP_ID=0x15), starting at byte offset 0. 15 30 00 0C 19.2 Read pedometer configuration variables This command reads all 16 bytes of the configuration variables from the Pedometer application (APP_ID=0x15), starting at byte offset 0. 15 10 00 10 19.3 Write pedometer configuration variables This command writes all 16 bytes of the configuration variables to the Pedometer application (APP_ID=0x15), starting at byte offset 0. 15 20 00 10 00 11 22 33 44 55 66 77 88 99 AA BB CC DD EE FF 19.4 Read GPIO Input/output status variables This command reads the status variable from the GPIO input/output application (APP_ID=0x19), starting at byte offset 0. 19 30 00 01 19.5 Read GPIO Input/output configuration variables This command reads all 3 bytes of the configuration variables from the GPIO input/output application (APP_ID=0x19), starting at byte offset 0. 19 10 00 03 19.6 Write GPIO Input/output configuration variables This command writes all 3 bytes of the configuration variables to the GPIO input/output application (APP_ID=0x19), starting at byte offset 0. 19 20 00 03 xx xx xx 19.7 Read Six direction status variables This command reads the two status variables from the Six Direction application (APP_ID=0x1A), starting at byte offset 0. 1A 30 00 02 19.8 Read Six direction configuration variables This command reads all 2 bytes of the configuration variables from the Six Direction application (APP_ID=0x1A), starting at byte offset 0. 1A 10 00 02 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 123 Write Six direction configuration variables 19.9 Write Six direction configuration variables This command writes all 3 bytes of the configuration variables to the Six Direction application (APP_ID=0x19), starting at byte offset 0. 1A 20 00 02 xx xx 19.10 Reset pedometer configuration variables to their defaults This command writes one byte of configuration variable to the Reset/Suspend/Clear application (APP_ID=0x17) starting at byte offset 1. This causes the scheduler to invoke the pedometer's reset function, pedometer_reset(). 17 20 01 01 20 19.11 Enable/disable the Pedometer application This command writes one byte of configuration variable to the Reset/Suspend/Clear application (APP_ID=0x17) starting at byte offset 5. This causes the scheduler to suspend the Pedometer application, even if the device is not stationary. 17 20 05 01 20 (disable) 17 20 05 01 00 (enable) 19.12 Configure the AFE range This command writes one byte of the configuration variable to the AFE application (APP_ID=0x06), starting at byte offset 0. Since the pedometer uses a normalized acceleration output provided by the AFE application, the g mode only affects the saturation level and noise. Regardless of what g mode the AFE is configured to, for or by other applications, the resolution seen by the Pedometer application is always 8 g. 06 20 00 01 40 (2 g mode) 06 20 00 01 80 (4 g mode) 06 20 00 10 00 (8 g mode) For more information on configuring the AFE range, see the "AFE configuration registers" section. 19.13 Configure output interrupt: Activity change on GPIO6 This command writes two bytes of the configuration variable to the GPIO application (APP_ID=0x03), starting at byte offset 0. This causes the GPIO application to copy the pedometer's ACTCHG status bit to GPIO6 after every new accelerometer sample. The host processor can trigger an interrupt on rising edges of this pin to receive notification when the activity level changes. 03 20 00 02 15 04 19 20 01 01 (AB & 6F) 19.14 Configure output interrupt: Step change on GPIO7 This command writes two bytes of the configuration variable to the GPIO application (APP_ID=0x03), starting at byte offset 2. This causes the GPIO application to copy the pedometer's STEPCHG status bit to GPIO7 after every new accelerometer sample. The host processor can trigger an interrupt on rising edges of this pin to receive notification when the step count changes. 03 20 02 02 15 05 19 20 01 01 (AB & 5F) MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 124 Freescale Semiconductor, Inc. Configure output interrupt: Suspend change on GPIO8 19.15 Configure output interrupt: Suspend change on GPIO8 This command writes two bytes of the configuration variable to the GPIO application (APP_ID=0x03) starting at byte offset 4. This causes the GPIO application to copy the pedometer's SUSPCHG status bit to GPIO8 after every new accelerometer sample. The host processor can trigger an interrupt on rising edges of this pin to receive notification when the pedometer autonomously suspends or resumes. 03 20 04 02 15 06 19 20 01 01 (AB & 3F) 19.16 Configure output interrupt: Merged flags on GPIO6 This command writes two bytes of the configuration variable to the GPIO application (APP_ID=0x03) starting at byte offset 0. This causes the GPIO application to copy the pedometer's MRGFL status bit to GPIO6 after every new accelerometer sample. The host processor can trigger an interrupt on rising edges of this pin to receive notification the activity-level, step-count, or suspend-state changes. 03 20 00 02 15 07 19 20 01 01 (AB & 6F) 19.17 Configure output interrupt: Every 10 steps on GPIO7 The first command writes one byte of configuration variable to the Pedometer application (APP_ID = 0x15), starting at byte offset 13. This causes the pedometer to coalesce steps and assert STEPCHG once every 10 steps. The second command writes two bytes of configuration variables to the GPIO application (APP_ID = 0x03), starting at byte offset 2. This causes the GPIO application to copy the pedometer's STEPCHG status bit to GPIO7 after every new accelerometer sample. 15 20 0D 01 0A 03 20 02 02 15 05 19 20 01 01 (AB & 5F) 19.18 Configure output interrupt: Device direction change on GPIO6 This command writes two bytes of the configuration variable to the GPIO application (APP_ID=0x03), starting at byte offset 0. This causes the GPIO application to copy the Six-Direction's SC_FLG status bit to GPIO6 after every new accelerometer sample. The host processor can trigger an interrupt on rising edges of this pin to receive notification when the activity level changes. 03 20 00 02 1A 07 19 20 01 01 (AB & 6F) 19.19 Wake up from Deep Sleep (Stop No Clock mode) By default, the MMA955xL initializes all applications after a hardware reset and then falls into Deep Sleep mode where all system clocks are stopped. A slave-port command can be used to wake up the clocks, enable the accelerometer, and execute the pedometer. This command writes one byte of configuration variable to the sleep/wake application (APP_ID=0x12) starting at byte offset 6. 12 20 06 01 00 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 125 20 Package Information The MMA9555L uses a 16-lead LGA package, case number 2094. Use the following link for the latest diagram of the package: www.freescale.com/files/shared/doc/package_info/98ASA00287D.pdf 20.1 Footprint and pattern information Pin 16 Pin 1 ID Pin 1 Package pad size 0.24 mm x 0.35 mm Figure 24. Package bottom view PCB land extension From the edge of the package PCB land pad PCB pad distance to package edge Package size (Measurements in mm) Figure 25. Package overlaid on PCB footprint diagram (top view) MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 126 Marking PCB land pad size 0.65 mm x 0.25 mm Solder mask opening Solder stencil opening 0.777 mm x 1.377 mm (PCB land + 0.0637 mm larger all around. Remove slivers between pads.) 0.62 mm x 0.22 mm (PCB land - 0.015 mm smaller all around) Figure 26. Recommended PCB footprint 20.2 Marking 5PQ7JFX 'SFFTDBMFDPEF "-:8 1BSUOVNCFS 5SBDFBCJMJUZEBUFDPEF "TTFNCMZTJUF -PUDPEF 8PSLXFFL MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 127 Tape and reel information 20.3 Tape and reel information Figure 27. Tape dimensions The devices are oriented on the tape as shown in Figure 28. The dot marked on each device indicates pin 1. 1JO %JSFDUJPO UPVOSFFM #BSDPEFMBCFM TJEFPGSFFM Figure 28. Tape and reel orientation MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 128 Freescale Semiconductor, Inc. Package Description 20.4 Package Description Use the following link for the latest diagram of the package: www.freescale.com/files/shared/doc/package_info/98ASA00287D.pdf MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 129 Revision History Revision number Revision date 1.0 10/2014 Description of changes Initial release of document. 2.0 3/2015 Features, 117 A for pedometer... was 190 A for pedometer Figure 2, Device pinout Changed pin 6 from RGPIO/SDA0/SDI to RGPIO1/SDA0/SDI Changed pin 8 from RGPIO3/SBB to RGPIO3/SSB Figures 3 and 4 Changed pin 7 from IO2/SCL1/SDO to IO2/SDO Changed pin 8 from IO3/SDA1/SSB to IO3/SSB Added Sections 4-10. Section 16.3.2.7, added Step Threshold Table 167, Version Reset changed from 0x01 to 0x02 Table 168, 7:0, VERSION, added 2: R1.34 Section 16.4.1, To write all the pedometer configuration registers,... MB3 = 0x11: Set the Count field to declare writing 17 bytes was MB3 = 0x10: Set the Count field to declare writing 16 bytes MB16-17 = 0x????: Set the Speed Period / Step Threshold Register was MB16-MB17 = 0x????: Set the Speed Period Added MB20 = 0x??: Set the Step Coalesce Bytes to send: 0x15, 0x20, 0x00, 0x11, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x?? was Bytes to send: 0x15, 0x20, 0x00, 0x10, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x??, 0x?? Section 16.4.1, To read all the pedometer configuration registers,... MB3: 0x11=number of bytes to read was MB3: 0x10=number of bytes to read MB2: 0x11 = actual number of bytes read was MB2: 0x10 = actual number of bytes read MB3: 0x11 = requested number of bytes to read was MB3: 0x10 = requested number of bytes to read MB15: male, filter time was MB15: male, filter time MB16: step period Added MB16: speed period MB17: step threshold was MB17: step coalesce Added MB20: step coalesce Deleted Added Section 19.3.2.9, Step Coalesce register Section 19.6, Write GPIO Input/output configuration variables was Write pedometer configuration variables Section 19.13, 19 20 01 01 (AB & 6F) was 19 20 01 01 Section 19.14, added 19 20 01 01 (AB & 5F) Section 19.15, 19 20 01 01 (AB & 3F) was 19 20 01 01 Section 19.16, 19 20 01 01 (AB & 6F) was 19 20 01 01 Section 19.17, 19 20 01 01 (AB & 5F) was 19 20 01 01 Section 19.18, 19 20 01 01 (AB & 6F) was 19 20 01 01 2.1 5/2015 Section 2.4.3, Note, deleted "Note that such a connection exists when the Master I2C interface is used (SDA1 function for pin 8)." Figure 3, changed resistor from R2 to R4 Table 150, Status register, changed Reset from 0x0001 to 0x0002 MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 130 Freescale Semiconductor, Inc. Revision number Revision date 2.2 6/2015 Description of changes * Table 146 StepRateFactor value changed to 1.30 * Section 16.2.5, "Calorie-expenditure calculation," on page 101 corrected Calorie-expenditure equation to match the calculation. MMA9555L Intelligent Pedometer Data Sheet, Rev. 2.2 Freescale Semiconductor, Inc. 131 Information in this document is provided solely to enable system and software implementers to use Freescale products. There are no express or implied copyright How to Reach Us: licenses granted hereunder to design or fabricate any integrated circuits based on the information in this document. Home Page: Freescale reserves the right to make changes without further notice to any products freescale.com herein. Freescale makes no warranty, representation, or guarantee regarding the Web Support: suitability of its products for any particular purpose, nor does Freescale assume any freescale.com/support liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters that may be provided in Freescale data sheets and/or specifications can and do vary in different applications, and actual performance may vary over time. All operating parameters, including "typicals," must be validated for each customer application by customer's technical experts. Freescale does not convey any license under its patent rights nor the rights of others. Freescale sells products pursuant to standard terms and conditions of sale, which can be found at the following address: freescale.com/salestermsandconditions. Freescale, the Freescale logo are trademarks of Freescale Semiconductor, Inc., Reg. U.S. Pat. & Tm. Off. The Energy Efficient Solutions logo is a trademark of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. (c) 2014-2015 Freescale Semiconductor, Inc. Document Number: MMA9555L Rev. 2.2, 6/2015 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Freescale Semiconductor: MMA9555LR1 KITMMA9555LEVM