RDA Microelectronics, Inc. RDA5870P Datasheet V1.0
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part without prior written permission of RDA. Page 11 of 22
Power Supply
The RDA5870P FM section integrated LDO which
supplies power to the chip. The external supply
voltage range is 1.8-5.5 V.
RESET and Control Interface select
The RDA5870P FM section is RESET itself When
VIO is Power up. And also support soft reset by
trigger 02H BIT1 from 0 to 1. The control interface
is I2C.
Control Interface
The I2C interface is compliant to I2C Bus
Specification 2.1. It includes two pins: SCL and
SDA. A I2C interface transfer begins with START
condition, a command byte and data bytes, each
byte has a followed ACK (or NACK) bit, and ends
with STOP condition. The command byte includes
a 7-bit chip address (0010000b) and a R/W bit.
The ACK (or NACK) is always sent out by receiver.
When in write transfer, data bytes is written out
from MCU, and when in read transfer, data bytes
is read out from RDA5870P. There is no visible
register address in I2C interface transfers. The
I2C interface has a fixed start register address
(0x02h for write transfer and 0x0Ah for read
transfer), and an internal incremental address
counter. If register address meets the end of
register file, 0x3Ah, register address will wrap
back to 0x00h. For write transfer, MCU programs
registers from register 0x02h high byte, then
register 0x02h low byte, then register 0x03h high
byte, till the last register. RDA5870P always gives
out ACK after every byte, and MCU gives out
STOP condition when register programming is
finished. For read transfer, after command byte
from MCU, RDA5870P sends out register 0x0Ah
high byte, then register 0x0Ah low byte, then
register 0x0Bh high byte, till receives NACK from
MCU. MCU gives out ACK for data bytes besides
last data byte. MCU gives out NACK for last data
byte, and then RDA5870P will return the bus to
MCU, and MCU will give out STOP condition.
Details please refer to RDA5870P Programming
Guide or RDA5802N Programming Guide and
Datasheet.