IDT72V51253L7-5BBI - Integrated Device Technology

JULY 2002

3.3V MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION

589,824 bits, 1,179,648 bits and

2,359,296 bits

IDT and the IDT logo are registered trademarks of Integrated Device Technology, Inc.

COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES

PRELIMINARY

IDT72V51233

IDT72V51243

IDT72V51253

FEATURES:

••

•Choose from among the following memory density options:

IDT72V51233 



Total Available Memory = 589,824 bits

IDT72V51243 



Total Available Memory = 1,179,648 bits

IDT72V51253 



Total Available Memory = 2,359,296 bits

••

•Configurable from 1 to 4 Queues

••

•Queues may be configured at master reset from the pool of

Total Available Memory in blocks of 512 x 18 or 1,024 x 9

••

•Independent Read and Write access per queue

••

•User programmable via serial port

••

•Default Multi-Queue device configurations

-IDT72V51233: 8,192 x 18 x 4Q or 16,384 x 9 x 4Q

-IDT72V51243: 16,384 x 18 x 4Q or 32,768 x 9 x 4Q

-IDT72V51253: 32,768 x 18 x 4Q or 65,536 x 9 x 4Q

••

•100% Bus Utilization, Read and Write on every clock cycle

••

•166 MHz High speed operation (6ns cycle time)

••

•3.7ns access time

••

•Individual, Active queue flags (OV, FF, PAE, PAF)

••

•4 bit parallel flag status on both read and write ports

••

•Provides continuous PAE and PAF status of up to 4 Queues

••

•Global Bus Matching - (All Queues have same Input Bus Width

and Output Bus Width)

••

•User Selectable Bus Matching Options:

- x18in to x18out

- x9in to x18out

- x18in to x9out

- x9in to x9out

••

•FWFT mode of operation on read port

••

•Partial Reset, clears data in single Queue

••

•Expansion of up to 8 Multi-Queue devices in parallel is available

••

•JTAG Functionality (Boundary Scan)

••

•Available in a 256-pin PBGA, 1mm pitch, 17mm x 17mm

••

•HIGH Performance submicron CMOS technology

••

•Industrial temperature range (-40°C to +85°C) is available

MULTI-QUEUE FIFO

FSTR

WEN

PAF

WRADD 5

WCLK

PAFn

x9, x18

DATA IN

REN

PAE

RDADD

ESTR

RCLK

PAEn

x9, x18

DATA OUT

WRITE CONTROL

Din Qout

READ CONTROL

WRITE FLAGS

READ FLAGS

5941 drw01

WADEN RADEN

DATA PATH FLOW DIAGRAM

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

DESCRIPTION:

The IDT72V51233/72V51243/72V51253 Multi-Queue FIFO device is a

single chip within which anywhere between 1 and 4 discrete FIFO queues

can be setup. All queues within the device have a common data input bus,

(write port) and a common data output bus, (read port). Data written into the

write port is directed to a respective queue via an internal de-multiplex

operation, addressed by the user. Data read from the read port is accessed

from a respective queue via an internal multiplex operation, addressed by

the user. Data writes and reads can be performed at high speeds up to

166MHz, with access times of 3.7ns. Data write and read operations are totally

independent of each other, a queue maybe selected on the write port and

a different queue on the read port or both ports may select the same queue

simultaneously.

The device provides Full flag and Output Valid flag status for the queue

selected for write and read operations respectively. Also a Programmable

Almost Full and Programmable Almost Empty flag for each queue is provided.

Two 4 bit programmable flag busses are available, providing status of all

queues, including queues not selected for write or read operations, these flag

busses provide an individual flag per queue.

Bus Matching is available on this device, either port can be 9 bits or 18 bits

wide. When Bus Matching is used the device ensures the logical transfer of data

throughput in a Little Endian manner.

The user has full flexibility configuring queues within the device, being able

to program the total number of queues between 1 and 4, the individual queue

depths being independent of each other. The programmable flag positions are

also user programmable. All programming is done via a dedicated serial port.

If the user does not wish to program the Multi-Queue device, a default option is

available that configures the device in a predetermined manner.

Both Master Reset and Partial Reset pins are provided on this device. A Master

Reset latches in all configuration setup pins and must be performed before

programming of the device can take place. A Partial Reset will reset the read and

write pointers of an individual FIFO queue, provided that the queue is selected

on both the write port and read port at the time of partial reset.

A JTAG test port is provided, here the Multi-Queue FIFO has a fully functional

Boundary Scan feature, compliant with IEEE 1149.1 Standard Test Access Port

and Boundary Scan Architecture.

See Figure 1, Multi-Queue FIFO Block Diagram for an outline of the functional

blocks within the device.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

x9, x18

Qout

OUTPUT

Q0 - Q17

WRADD

WADEN

INPUT

DEMUX

WCLK WEN

Write Control

Logic

Din

Write Pointers

Active Q

Flags

PAF

General Flag

Monitor

FSTR

PAFn

FSYNC

PAF

Reset

Logic

Serial

Multi-Queue

Programming

PAE/ PAF

Offset

TMS

TDI

TDO

TCK

TRST

PRS

MRS

SCLK

SENI

RCLK

REN

Read Control

Logic

Read Pointers

Active Q

Flags

PAE

General Flag

Monitor ESTR

ESYNC

RDADD

RADEN

FXO

FXI

EXI

EXO

5941 drw02

x9, x18

ID0

ID1

ID2

Device ID

3 Bit

JTAG

Logic

SENO

DFM

MAST

PAE

Upto 4

FIFO

Queues

0.5 Mbit

1.1 Mbit

2.3 Mbit

Dual Port

Memory

OUTPUT

MUX

D0 - D17

PAEn

Figure 1. Multi-Queue Block Diagram

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

D14

D13 D12 D10 Q9D7 Q6D4 Q3D1 ID1TCK TDO Q12 Q14 Q15

D15

D16 D11 D9 Q8D6 Q5D3 Q2D0 ID0TMS TDI Q11 Q13 DNC

D17

GND GND D8 Q7D5 Q4D2 Q1

TRST Q0

GND ID2 Q10 Q17 DNC

GND

GND GND VCC VCC

VCC VCCVCC VCC

VCC VCC

VCC VCC Q16 DNC DNC

GND

GND GND VCC VCC

VCC VCCVCC VCCVCC VCCGND GND DNC DNC DNC

GND

GND GND VCC VCCVCC VCCGND GNDGND GNDGND GND DNC DNC DNC

GND

GND GND VCC VCCVCC VCCGND GNDGND GNDGND GND DNC DNC DNC

GND

GND GND VCC VCC

GND GNDGND GNDGND GNDGND GND DNC DNC DNC

GND

GND GND VCC VCCGND GNDGND GNDGND GNDGND GND GND DNC DNC

GND

GND GND VCC VCCVCC VCC

GND GNDGND GNDGND GND GND MAST FM

DFM DF VCC VCCVCC VCCGND GNDGND GNDGND GND GND IW OW

SENO

SENI SO VCC VCCVCC VCCVCC VCCVCC VCCGND GND OE RDADD0 RDADD1

WRADD1

WRADD0 SCLK VCC VCCVCC VCCVCC VCCVCC VCCVCC VCC RDADD2 GND GND

GND

GND GND WADEN PAE3PAF3 DNCDNC DNCDNC PAE

FF OV

FSYNC FSTR PAE2PAF2 DNCDNC DNCDNC DNC

PAF RADEN ESTR ESYNC

FXI FXO PAF0PAE1PAF1 DNC

WEN REN

WCLK RCLK

PRS MRS PAE0

12 3 4 135126117108 9 14 15 16

5941 drw03

A1 BALL PAD CORNER

EXO EXI

WRADD3 WRADD2

WRADD4

RDADD4 RDADD5RDADD3

DNC

PIN CONFIGURATION

PBGA (BB256-1, order code: BB)

TOP VIEW

NOTE:

1. DNC - Do Not Connect.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

DETAILED DESCRIPTION

MULTI-QUEUE STRUCTURE

The IDT Multi-Queue FIFO has a single data input port and single data output

port with up to 4 FIFO queues in parallel buffering between the two ports. The

user can setup between 1 and 4 FIFO Queues within the device. These queues

can be configured to utilize the total available memory, providing the user with

full flexibility and ability to configure the queues to be various depths, indepen-

dent of one another.

MEMORY ORGANIZATION/ ALLOCATION

The memory is organized into what is known as “blocks”, each block being

512 x 18 or 1,024 x 9 bits. When the user is configuring the number of queues

and individual queue sizes the user must allocate the memory to respective

queues, in units of blocks, that is, a single queue can be made up from 0 to m

blocks, where m is the total number of blocks available within a device. Also the

total size of any given queue must be in increments of 512 x 18 or 1,024 x 9.

For the IDT72V51233, IDT72V51243 and IDT72V51253 the Total Available

Memory is 64, 128 and 256 blocks respectively (a block being 512 x 18 or 1,024

x 9). If any port is configured for x18 bus width, a block size is 512 x 18. If both

the write and read ports are configured for x9 bus width, a block size is 1,024

x 9. Queues can be built from these blocks to make any size queue desired and

any number of queues desired.

BUS WIDTHS

The input port is common to all FIFO queues within the device, as is the output

port. The device provides the user with Bus Matching options such that the input

port and output port can be either x9 or x18 bits wide, the read and write port

widths being set independently of one another. Because the ports are common

to all queues the width of the queues is not individually set, so that the input width

of all queues are equal and the output width of all queues are equal.

WRITING TO & READING FROM THE MULTI-QUEUE

Data being written into the device via the input port is directed to a discrete

FIFO queue via the write queue select address inputs. Conversely, data being

read from the device read port is read from a queue selected via the read queue

select address inputs. Data can be simultaneously written into and read from the

same FIFO queue or different FIFO queues. Once a queue is selected for data

writes or reads, the writing and reading operation is performed in the same

manner as conventional IDT synchronous FIFO’s, utilizing clocks and enables,

there is a single clock and enable per port. When a specific queue is addressed

on the write port, data placed on the data inputs is written to that queue

sequentially based on the rising edge of a write clock provided setup and hold

times are met. Conversely, data is read on to the output port after an access time

from a rising edge on a read clock.

The operation of the write port is comparable to the function of a conventional

FIFO operating in standard IDT mode. Write operations can be performed on

the write port provided that the queue currently selected is not full, a full flag output

provides status of the selected queue. The operation of the read port is

comparable to the function of a conventional FIFO operating in FWFT mode.

When a FIFO queue is selected on the output port, the next word in that queue

will automatically fall through to the output register. All subsequent words from

that queue require an enabled read cycle. Data cannot be read from a selected

queue if that queue is empty, the read port provides an Output Valid flag indicating

when data read out is valid. If the user switches to a queue that is empty, the

last word from the previous queue will remain on the output register.

As mentioned, the write port has a full flag, providing full status of the selected

queue. Along with the full flag a dedicated almost full flag is provided, this almost

full flag is similar to the almost full flag of a conventional IDT FIFO. The device

provides a user programmable almost full flag for all 4 FIFO queues and when

a respective queue is selected on the write port, the almost full flag provides status

for that queue. Conversely, the read port has an output valid flag, providing

status of the data being read from the queue selected on the read port. As well

as the output valid flag the device provides a dedicated almost empty flag. This

almost empty flag is similar to the almost empty flag of a conventional IDT FIFO.

The device provides a user programmable almost empty flag for all 4 FIFO

queues and when a respective queue is selected on the read port, the almost

empty flag provides status for that queue.

PROGRAMMABLE FLAG BUSSES

In addition to these dedicated flags, full & almost full on the write port and output

valid & almost empty on the read port, there are two flag status busses. An almost

full flag status bus is provided, this bus is 4 bits wide. Also, an almost empty flag

status bus is provided, again this bus is 4 bits wide. The purpose of these flag

busses is to provide the user with a means by which to monitor the data levels

within FIFO queues that may not be selected on the write or read port. As

mentioned, the device provides almost full and almost empty registers (program-

mable by the user) for each of the 4 FIFO queues in the device.

The 4 bit PAEn and 4 bit PAFn busses provide a discrete status of the Almost

Empty and Almost Full conditions of all 4 queue's. If the device is programmed

for less than 4 queue's, then there will be a corresponding number of active

outputs on the PAEn and PAFn busses.

The flag busses can provide a continuous status of all queues. If devices are

connected in expansion mode the individual flag busses can be left in a discrete

form, providing constant status of all queues, or the busses of individual devices

can be connected together to produce a single bus of 4 bits. The device can

then operate in a "Polled" or "Direct" mode.

When operating in polled mode the flag bus provides status of each device

sequentially, that is, on each rising edge of a clock the flag bus is updated to show

the status of each device in order. The rising edge of the write clock will update

the Almost Full bus and a rising edge on the read clock will update the Almost

Empty bus.

When operating in direct mode the device driving the flag bus is selected by

the user. The user addresses the device that will take control of a respective

flag bus, these PAFn and PAEn flag busses operating independently of one

another. Addressing of the Almost Full flag bus is done via the write port and

addressing of the Almost Empty flag bus is done via the read port.

EXPANSION

Expansion of Multi-Queue devices is also possible, up to 8 devices can be

connected in a parallel fashion providing the possibility of both depth expansion

or queue expansion. Depth Expansion means expanding the depths of

individual queues. Queue expansion means increasing the total number of

queues available. Depth expansion is possible by virtue of the fact that more

memory blocks within a Multi-Queue device can be allocated to increase the

depth of a queue. For example, depth expansion of 8 devices provides the

possibility of 8 queues of 32K x 18 deep within the IDT72V51233, 64K x 18 deep

within the IDT72V51243 and 128K x 18 deep within the IDT72V51253, each

queue being setup within a single device utilizing all memory blocks available

to produce a single queue. This is the deepest FIFO queue that can setup within

a device.

For queue expansion of the 4 queue device, a maximum number of 32 (8

x 4) queues may be setup, each queue being 4K x18 or 2K x 9 deep, if less

queues are setup, then more memory blocks will be available to increase queue

depths if desired. When connecting Multi-Queue devices in expansion mode

all respective input pins (data & control) and output pins (data & flags), should

be “connected” together between individual devices.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

D[17:0] Data Input Bus LVTTL These are the 18 data input pins. Data is written into the device via these input pins on the rising edge

Din (See Pin INPUT of WCLK provided that WEN is LOW. Due to bus matching not all inputs may be used, any unused inputs

table for details) should be tied LOW.

DF(1) Default Flag LVTTL If the user requires default programming of the Multi-Queue device, this pin must be setup before Master

(L3) INPUT Reset and must not toggle during any device operation. The state of this input at master reset determines

the value of the PAE/PAF flag offsets. If DF is LOW the value is 8, if DF is HIGH the value is 128.

DFM(1) Default Mode LVTTL The Multi-Queue device requires programming after master reset. The user can do this serially via the

(L2) INPUT serial port, or the user can use the default method. If DFM is LOW at master reset then serial mode will be

selected, if HIGH then default mode is selected.

ESTR PAEn Flag Bus LVTTL If direct operation of the PAEn bus has been selected, the ESTR input is used in conjunction with RCLK

(R15) Strobe INPUT and the RDADD bus to select a device for its queues to be placed on to the PAEn bus outputs. A device

addressed via the RDADD bus is selected on the rising edge of RCLK provided that ESTR is HIGH. If

Polled operations has been selected, ESTR should be tied inactive, LOW. Note, that a PAEn flag bus

selection cannot be made, (ESTR must NOT go active) until programming of the part has been completed

and SENO has gone LOW.

ESYNC PAEn Bus Sync LVTTL ESYNC is an output from the Multi-Queue device that provides a synchronizing pulse for the PAEn bus

(R16) OUTPUT during Polled operation of the PAEn bus. During Polled operation each devices queue status flags are

loaded on to the PAEn bus outputs sequentially based on RCLK. The first RCLK rising edge loads device 1

on to PAEn, the second RCLK rising edge loads device 2 and so on. During the RCLK cycle that a selected

device is placed on to the PAEn bus, the ESYNC output will be HIGH.

EXI PAEn Bus LVTTL The EXI input is used when Multi-Queue devices are connected in expansion mode and Polled PAEn/

(T16) Expansion In INPUT bus operation has been selected . EXI of device ‘N’ connects directly to EXO of device ‘N-1’. The EXI

receives a token from the previous device in a chain. In single device mode the EXI input should be tied

LOW if the PAEn bus is operated in direct mode. If the PAEn bus is operated in polled mode the EXI input

should be connected to the EXO output of the same device. In expansion mode the EXI of the first device

should be tied LOW, when direct mode is selected.

EXO PAEn Bus LVTTL EXO is an output that is used when Multi-Queue devices are connected in expansion mode and Polled

(T15) Expansion Out OUTPUT PAEn bus operation has been selected . EXO of device ‘N’ connects directly to EXI of device ‘N+1’. This

pin pulses HIGH when device N places its PAE status on to the PAEn bus with respect to RCLK. This pulse

(token) is then passed on to the next device in the chain ‘N+1’ and on the next RCLK rising edge the first

quadrant of device N+1 will be loaded on to the PAEn bus. This continues through the chain and EXO

of the last device is then looped back to EXI of the first device. The ESYNC output of each device in the

chain provides synchronization to the user of this looping event.

FF Full Flag LVTTL This pin provides the full flag output for the active FIFO queue, that is, the queue selected on the input

(P8) OUTPUT port for write operations, (selected via WCLK, WRADD bus and WADEN). On the WCLK cycle after a

queue selection, this flag will show the status of the newly selected queue. Data can be written to this queue

on the next cycle provided FF is HIGH. This flag has High-Impedance capability, this is important during

expansion of devices, when the FF flag output of up to 8 devices may be connected together on a common

line. The device with a queue selected takes control of the FF bus, all other devices place their FF output

into High-Impedance. When a queue selection is made on the write port this output will switch from

High-Impedance control on the next WCLK cycle. This flag is synchronized to WCLK.

FM(1) Flag Mode LVTTL This pin is setup before a master reset and must not toggle during any device operation. The state of the

(K16) INPUT FM pin during Master Reset will determine whether the PAFn and PAEn flag busses operate in either Polled

or Direct mode. If this pin is HIGH the mode is Polled, if LOW then it will be Direct.

FSTR PAFn Flag Bus LVTTL If direct operation of the PAFn bus has been selected, the FSTR input is used in conjunction with WCLK

(R4) Strobe INPUT and the WRADD bus to select a device for its queues to be placed on to the PAFn bus outputs. A device

addressed via the WRADD bus is selected on the rising edge of WCLK provided that FSTR is HIGH. If

Polled operations has been selected, FSTR should be tied inactive, LOW. Note, that a PAFn flag bus

selection cannot be made, (FSTR must NOT go active) until programming of the part has been completed

and SENO has gone LOW.

PIN DESCRIPTIONS

Symbol & Name I/O TYPE Description

Pin No.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

FSYNC PAFn Bus Sync LVTTL FSYNC is an output from the Multi-Queue device that provides a synchronizing pulse for the PAFn bus

(R3) OUTPUT during Polled operation of the PAFn bus. During Polled operation each quadrant of queue status flags

is loaded on to the PAFn bus outputs sequentially based on WCLK. The first WCLK rising edge loads

device1 on to the PAFn bus outputs, the second WCLK rising edge loads device 2 and so on. During the

WCLK cycle that a selected device is placed on to the PAFn bus, the FSYNC output will be HIGH.

FXI PAFn Bus LVTTL The FXI input is used when Multi-Queue devices are connected in expansion mode and Polled PAFn

(T2) Expansion In INPUT bus operation has been selected . FXI of device ‘N’ connects directly to FXO of device ‘N-1’. The FXI

receives a token from the previous device in a chain. In single device mode the FXI input should be tied

LOW if the PAEn bus is operated in direct mode. If the PAEn bus is operated in polled mode the FXI input

should be connected to the FXO output of the same device. In expansion mode the FXI of the first device

should be tied LOW, when direct mode is selected.

FXO PAFn Bus LVTTL FXO is an output that is used when Multi-Queue devices are connected in expansion mode and Polled

(T3) Expansion Out OUTPUT PAFn bus operation has been selected . FXO of device ‘N’ connects directly to FXI of device ‘N+1’. This

pin pulses HIGH when device N places its PAF status on to the PAFn bus with respect to WCLK. This pulse

(token) is then passed on to the next device in the chain ‘N+1’ and on the next WCLK rising edge the first

quadrant of device N+1 will be loaded on to the PAFn bus. This continues through the chain and FXO

of the last device is then looped back to FXI of the first device. The FSYNC output of each device in the

chain provides synchronization to the user of this looping event.

ID[2:0](1) Device ID Pins LVTTL For the 4Q Multi-Queue device the WRADD address bus is 5 bits and RDADD address bus is 6 bits wide.

(ID2-C9 INPUT When a queue selection takes place the 3 MSB’s of this address bus are used to address the specific device

ID1-A10 (the LSB’s are used to address the queue within that device). During write/read operations the 3 MSB’s

ID0-B10) of the address are compared to the device ID pins. The first device in a chain of Multi-Queue’s (connected

in expansion mode), may be setup as ‘000’, the second as ‘001’ and so on through to device 8 which is

‘111’, however the ID does not have to match the device order. In single device mode these pins should

be setup as ‘000’ and the 3 MSB’s of the WRADD and RDADD address busses should be tied LOW. The

ID[2:0] inputs setup a respective devices ID during master reset. These ID pins must not toggle during

any device operation. Note, the device selected as the ‘Master’ does not have to have the ID of ‘000’.

IW(1) Input Width LVTTL IW selects the bus width for the data input bus. If IW is LOW during a Master Reset then the bus width

(L15) INPUT is x18, if HIGH then it is x9.

MAST(1) Master Device LVTTL The state of this input at Master Reset determines whether a given device (within a chain of devices), is the

(K15) INPUT Master device or a Slave. If this pin is HIGH, the device is the master, if it is LOW then it is a Slave. The

master device is the first to take control of all outputs after a master reset, all slave devices go to

High-Impedance, preventing bus contention. If a Multi-Queue device is being used in single device mode,

this pin must be set HIGH.

MRS Master Reset LVTTL A master reset is performed by taking MRS from HIGH to LOW, to HIGH. Device programming is required

(T9) INPUT after master reset.

OE Output Enable LVTTL The Output enable signal is an Asynchronous signal used to provide three-state control of the Multi-Queue

(M14) INPUT data output bus, Qout. If a device has been configured as a “Master” device, the Qout data outputs will

be in a Low Impedance condition if the OE input is LOW. If OE is HIGH then the Qout data outputs will be

in High Impedance. If a device is configured a “Slave” device, then the Qout data outputs will always be

in High Impedance until that device has been selected on the Read Port, at which point OE provides three-

state of that respective device.

OV Output Valid Flag LVTTL This output flag provides output valid status for the data word present on the Multi-Queue FIFO data output

(P9) OUTPUT port, Qout. This flag is therefore, 2-stage delayed to match the data output path delay. That is, there is

a 2 RCLK cycle delay from the time a given queue is selected for reads, to the time the OV flag represents

the data in that respective queue. When a selected queue on the read port is read to empty, the OV flag

will go HIGH, indicating that data on the output bus is not valid. The OV flag also has High-Impedance

capability, required when multiple devices are used and the OV flags are tied together.

OW(1) Output Width LVTTL OW selects the bus width for the data output bus. If OW is LOW during a Master Reset then the bus width

(L16) INPUT is x18, if HIGH then it is x9.

PIN DESCRIPTIONS (CONTINUED)

Symbol & Name I/O TYPE Description

Pin No.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

PAE Programmable LVTTL This pin provides the Almost-Empty flag status for the FIFO queue that has been selected on the output

(P10) Almost-Empty Flag OUTPUT port for read operations, (selected via RCLK, RDADD and RADEN). This pin is LOW when the selected

FIFO queue almost-empty. This flag output may be duplicated on one of the PAEn bus lines. This flag

is synchronized to RCLK.

PAEn Programmable LVTTL On the 4Q device the PAEn bus is 4 bits wide. This output bus provides PAE status of all 4 queues, within a

(PAE3-P13 Almost-Empty OUTPUT selected device. During FIFO read/write operations these outputs provide programmable empty flag status

PAE2-R13 Flag Bus in either director polled mode. The mode of flag operation is determined during master reset via the state of

PAE1-T13 the FM input. This flag bus is capable of High-Impedance state, this is important during expansion of

PAE0-T14) Multi-Queue devices. During direct operation the PAEn bus is updated to show the PAE status of queues

within a selected device. Selection is made using RCLK, ESTR and Flag Bus RDADD. During Polled

operation the PAEn bus is loaded with the PAE status of Multi-Queue FIFO devices sequentially based

on the rising edge of RCLK.

PAF Programmable LVTTL This pin provides the Almost-Full flag status for the FIFO queue that has been selected on the input port for

(R8) Almost-Full Flag OUTPUT write operations, (selected via WCLK, WRADD and WADEN). This pin is LOW when the selected FIFO

queue is almost-full. This flag output may be duplicated on one of the PAFn bus lines. This flag is

synchronized to WCLK.

PAFn Programmable LVTTL On the 4Q device the PAFn bus is 4 bits wide. This output bus provides PAF status of all 4 queues, within a

(PAE3-P5 Almost-Full OUTPUT selected device. During FIFO read/write operations these outputs provide programmable full flag status, in

PAE2-R5 Flag Bus either direct or polled mode. The mode of flag operation is determined during master reset via the state of

PAE1-T5 the FM input. This flag bus is capable of High-Impedance state, this is important during expansion of

PAE0-T4) Multi-Queue devices. During direct operation the PAFn bus is updated to show the PAF status of a queues

within a selected device. Selection is made using WCLK, FSTR, WRADD and WADEN. During

Polled operation the PAFn bus is loaded with the PAF status of Multi-Queue FIFO devices sequentially

based on the rising edge of WCLK.

PRS Partial Reset LVTTL A Partial Reset can be performed on a single queue selected within the Multi-Queue device. Before a Partial

(T8) INPUT Reset can be performed on a queue, that queue must be selected on both the write port and read port

2 clock cycles before the reset is performed. A Partial Reset is then performed by taking PRS LOW for

one WCLK cycle and one RCLK cycle. The Partial Reset will only reset the read and write pointers to

the first memory location, none of the devices configuration will be changed.

Q[17:0] Data Output Bus LVTTL These are the 18 data output pins. Data is read out of the device via these output pins on the rising edge

Qout (See Pin OUTPUT of RCLK provided that REN is LOW, OE is LOW and the FIFO queue is selected. Due to bus matching

table for details) not all outputs may be used, any unused outputs should not be connected.

RADEN Read Address LVTTL The RADEN input is used in conjunction with RCLK and the RDADD address bus to select a queue to

(R14) Enable INPUT be read from. A FIFO queue addressed via the RDADD bus is selected on the rising edge of RCLK

provided that RADEN is HIGH. RADEN cannot be HIGH for the same RCLK cycle as ESTR. Note, that

a read queue selection cannot be made, (RADEN must NOT go active) until programming of the part has

been completed and SENO has gone LOW.

RCLK Read Clock LVTTL When enabled by REN, the rising edge of RCLK reads data from the selected FIFO queue via the output

(T10) INPUT bus Qout. The FIFO queue to be read is selected via the RDADD address bus and a rising edge of RCLK

while RADEN is HIGH. A rising edge of RCLK in conjunction with ESTR and RDADD will also select the

device to be placed on the PAEn bus during direct flag operation. During polled flag operation the PAEn

bus is cycled with respect to RCLK and the ESYNC signal is synchronized to RCLK. The PAE and OV

outputs are all synchronized to RCLK. During device expansion the EXO and EXI signals are based on

RCLK. RCLK must be continuous and free-running.

RDADD Read Address Bus LVTTL For the 4Q device the RDADD bus is 6 bits. The RDADD bus is a dual purpose address bus. The first

[5:0] INPUT function of RDADD is to select a FIFO queue to be read from. The least significant 2 bits of the bus,

(See next page RDADD[1:0] are used to address 1 of 4 possible queues within a Multi-Queue device. Address pin,

for details) RDADD[2] provides the user with a Null-Q address. If the user does not wish to address one of the 4 queues,

a Null-Q can be addressed using this pin. The Null-Q operation is discussed in more detail later. The most

significant 3 bits, RDADD[5:3] are used to select 1 of 8 possible Multi-Queue devices that may be connected

in expansion mode. These 3 MSB’s will address a device with the matching ID code. The address present

on the RDADD bus will be selected on a rising edge of RCLK provided that RADEN is HIGH, (note, that

PIN DESCRIPTIONS (CONTINUED)

Symbol & Name I/O TYPE Description

Pin No.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

RDADD Read Address Bus LVTTL data can be placed on to the Qout bus, read from the previously selected FIFO queue on this RCLK edge).

[5:0] INPUT On the next rising RCLK edge after a read queue select, a data word from the previous queue will be

(Continued) placed onto the outputs, Qout, regardless of the REN input. Two RCLK rising edges after read queue select,

(RDADD5-P16 data will be placed on to the Qout outputs from the newly selected queue, regardless of REN due to the

RDADD4-P15 first word fall through effect.

RDADD3-P14 The second function of the RDADD bus is to select the device of FIFO queues to be loaded on to the PAEn

RDADD2-N14 bus during strobed flag mode. The most significant 3 bits, RDADD[5:3] are again used to select 1 of 8

RDADD1-M16 possible Multi-Queue devices that may be connected in expansion mode. Address bits RDADD[2:0] are

RDADD0-M15) don’t care during device selection. The device address present on the RDADD bus will be selected on the

rising edge of RCLK provided that ESTR is HIGH, (note, that data can be placed on to the Qout bus, read

from the previously selected FIFO Q on this RCLK edge). Please refer to Table 2 for details on RDADD bus.

REN Read Enable LVTTL The REN input enables read operations from a selected FIFO queue based on a rising edge of RCLK.

(T11) INPUT A queue to be read from can be selected via RCLK, RADEN and the RDADD address bus regardless

of the state of REN. Data from a newly selected queue will be available on the Qout output bus on the second

RCLK cycle after queue selection regardless of REN due to the FWFT operation. A read enable is not

required to cycle the PAEn bus (in polled mode) or to select the device , (in direct mode).

SCLK Serial Clock LVTTL If serial programming of the Multi-Queue device has been selected during master reset, the SCLK input

(N3) INPUT clocks the serial data through the Multi-Queue device. Data setup on the SI input is loaded into the device

on the rising edge of SCLK provided that SENI is enabled, LOW. When expansion of devices is performed

the SCLK of all devices should be connected to the same source.

SENI Serial Input Enable LVTTL During serial programming of a Multi-Queue device, data loaded onto the SI input will be clocked into the

(M2) INPUT part (via a rising edge of SCLK), provided the SENI input of that device is LOW. If multiple devices are

cascaded, the SENI input should be connected to the SENO output of the previous device. So when serial

loading of a given device is complete, its SENO output goes LOW, allowing the next device in the chain

to be programmed (SENO will follow SENI of a given device once that device is programmed). The SENI

input of the master device (or single device), should be controlled by the user.

SENO Serial Output LVTTL This output is used to indicate that serial programming or default programming of the Multi-Queue device

(M1) Enable OUTPUT has been completed. SENO follows SENI once programming of a device is complete. Therefore, SENO

will go LOW after programming provided SENI is LOW, once SENI is taken HIGH again, SENO will also

go HIGH. When the SENO output goes LOW, the device is ready to begin normal read/write operations.

If multiple devices are cascaded and serial programming of the devices will be used, the SENO output

should be connected to the SENI input of the next device in the chain. When serial programming of the

first device is complete, SENO will go LOW, thereby taking the SENI input of the next device LOW and

so on throughout the chain. When a given device in the chain is fully programmed the SENO output

essentially follows the SENI input. The user should monitor the SENO output of the final device in the chain.

When this output goes LOW, serial loading of all devices has been completed.

SI Serial In LVTTL During serial programming this pin is loaded with the serial data that will configure the Multi-Queue devices.

(L1) INPUT Data present on SI will be loaded on a rising edge of SCLK provided that SENI is LOW. In expansion

mode the serial data input is loaded into the first device in a chain. When that device is loaded and its SENO

has gone LOW, the data present on SI will be directly output to the SO output. The SO pin of the first device

connects to the SI pin of the second and so on. The Multi-Queue device setup registers are shift registers.

SO Serial Out LVTTL This output is used in expansion mode and allows serial data to be passed through devices in the chain

(M3) OUTPUT to complete programming of all devices. The SI of a device connects to SO of the previous device in the

chain. The SO of the final device in a chain should not be connected.

TCK JTAG Clock LVTTL Clock input for JTAG function. TMS and TDI are sampled on the rising edge of TCK. TDO is output on

(A8) INPUT the falling edge of TCK.

TDI Test Data Input LVTTL During JTAG boundary scan operation test data is serially loaded via TDI on the rising edge of TCK.

(B9) INPUT This is also the data for the Instruction Register, JTAG ID Register and Bypass Register.

TDO Test Data Output LVTTL During JTAG boundary scan operation test data is serially output via TDO on the falling edge of TCK.

(A9) OUTPUT This output is in High-Impedance except when shifting data while in SHIFT-DR and SHIFT-IR controller

states.

PIN DESCRIPTIONS (CONTINUED)

Symbol & Name I/O TYPE Description

Pin No.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

NOTE:

1. Inputs should not change after Master Reset.

TMS JTAG Mode Select LVTTL TMS is a serial input pin. Bits are serially loaded on the rising edge of TCK, which selects 1 of 5 modes

(B8) INPUT of operation for the JTAG boundary scan.

TRST JTAG Reset LVTTL TRST is the asynchronous reset pin for the JTAG controller. If the JTAG port is not utilized, TRST should

(C7) INPUT be tied to GND.

WADEN Write Address LVTTL The WADEN input is used in conjunction with WCLK and the WRADD address bus to select a queue to

(P4) Enable INPUT be written in to. A FIFO queue addressed via the WRADD bus is selected on the rising edge of WCLK

provided that WADEN is HIGH. WADEN cannot be HIGH for the same WCLK cycle as FSTR. Note, that

a write queue selection cannot be made, (WADEN must NOT go active) until programming of the part has

been completed and SENO has gone LOW.

WCLK Write Clock LVTTL When enabled by WEN, the rising edge of WCLK writes data into the selected FIFO queue via the input

(T7) INPUT bus, Din. The FIFO queue to be written to is selected via the WRADD address bus and a rising edge

of WCLK while WADEN is HIGH. A rising edge of WCLK in conjunction with FSTR and WRADD will also

select the device to be placed on the PAFn bus during direct flag operation. During polled flag operation

the PAFn bus is cycled with respect to WCLK and the FSYNC signal is synchronized to WCLK. The PAFn,

PAF and FF outputs are all synchronized to WCLK. During device expansion the FXO and FXI signals

are based on WCLK. The WCLK must be continuous and free-running.

WEN Write Enable LVTTL The WEN input enables write operations to a selected FIFO queue based on a rising edge of WCLK.

(T6) INPUT A queue to be written to can be selected via WCLK, WADEN and the WRADD address bus regardless

of the state of WEN. Data present on Din can be written to a newly selected queue on the second WCLK

cycle after queue selection provided that WEN is LOW. A write enable is not required to cycle the PAFn

bus (in polled mode) or to select the device , (in direct mode).

WRADD Write Address Bus LVTTL For the 4Q device the WRADD bus is 5 bits. The WRADD bus is a dual purpose address bus. The first

[4:0] INPUT function of WRADD is to select a FIFO queue to be written to. The least significant 2 bits of the bus,

(WRADD4-T1 WRADD[1:0] are used to address 1 of 4 possible queues within a Multi-Queue device. The most significant

WRADD3-R1 3 bits, WRADD[4:2] are used to select 1 of 8 possible Multi-Queue devices that may be connected in

WRADD2-R2 expansion mode. These 3 MSB’s will address a device with the matching ID code. The address present

WRADD1-N1 on the WRADD bus will be selected on a rising edge of WCLK provided that WADEN is HIGH, (note, that

WRADD0-N2) data present on the Din bus can be written into the previously selected FIFO queue on this WCLK edge

and on the next rising WCLK also, providing that WEN is LOW). Two WCLK rising edges after write queue

select, data can be written into the newly selected queue.

The second function of the WRADD bus is to select the device of FIFO queues to be loaded on to the

PAFn bus during strobed flag mode. The most significant 3 bits, WRADD[4:2] are again used to select

1 of 8 possible Multi-Queue devices that may be connected in expansion mode. Address bits WRADD[1:0]

are don’t care during device selection. The device address present on the WRADD bus will be selected

on the rising edge of WCLK provided that FSTR is HIGH, (note, that data can be written into the previously

selected FIFO queue on this WCLK edge). Please refer to Table 1 for details on the WRADD bus.

VCC (See Pin +3.3V Supply Power These are VCC power supply pins and must all be connected to a +3.3V supply rail.

table for details)

GND (See Pin Ground Pin Power These are Ground pins and must all be connected to the GND supply rail.

table for details)

PIN DESCRIPTIONS (CONTINUED)

Symbol & Name I/O TYPE Description

Pin No.

**Please continue to next page for Pin Number Table.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

PIN NUMBER TABLE

Symbol Name I/O TYPE Pin Number

D[17:0] Data Input Bus LVTTL D17-C1, D(16,15)-B(2,1), D(14-12)-A(1-3), D11-B3, D10-A4, D9-B4, D8-C4, D7-A5, D6-B5, D5-C5,

Din INPUT D4-A6, D3-B6, D2-C6, D1-A7, D0-B7

Q[17:0] Data Output Bus LVTTL Q17-C15, Q16-D14, Q(15,14)-A(16,15), Q13-B15, Q12-A14, Q11-B14, Q10-C14, Q9-A13, Q8-B13,

Qout OUTPUT Q7-C13, Q6-A12, Q5-B12, Q4-C12, Q3-A11, Q2-B11, Q(1,0)-C(11,10)

VCC +3.3V Supply Power D(4-13), E(4-7,10-13), F(4,5,12,13), G(4,5,12,13), H(4,13), J(4,13), K(4,5,12,13), L(4,5,12,13),

M(4-7,10-13), N(4-13)

GND Ground Pin Power C(2,3,8), D(1-3), E(1-3,8,9), F(1-3,6-11), G(1-3,6-11), H(1-3,5-12), J(1-3,5-12,14), K(1-3,6-11,14),

L(6-11,14), M(8,9), N(15,16), P(1-3)

DNC Do Not Connect B16, C16, D(15,16), E(14-16), F(14-16), G(14-16), H(14-16), J(15,16), P(6,7,11,12), R(6,7,9-12), T(12)

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

Symbol Rating Com'l & Ind'l Unit

VTERM Terminal Voltage –0.5 to +4.5 V

with respect to GND

TSTG Storage Temperature –55 to +125 °C

IOUT DC Output Current –50 to +50 mA

DC ELECTRICAL CHARACTERISTICS

(Commercial: VCC = 3.3V ± 0.15V, TA = 0°C to +70°C;Industrial: VCC = 3.3V ± 0.15V, TA = 40°C to +85°C; JEDEC JESD8-A compliant)

Symbol Parameter Min. Max. Unit

ILI(1) Input Leakage Current –10 10 µA

ILO(2) Output Leakage Current –10 10 µA

VOH Output Logic “1” Voltage, IOH = –8 mA 2. 4 — V

VOL Output Logic “0” Voltage, IOL = 8 mA — 0. 4 V

ICC1(3,4,5) Active Power Supply Current — 1 00 mA

ICC2(3,6) Standby Current — 25 mA

ABSOLUTE MAXIMUM RATINGS

RECOMMENDED DC OPERATING

CONDITIONS

NOTES:

1. Measurements with 0.4 ≤ VIN ≤ VCC.

2. OE ≥ VIH, 0.4 ≤ VOUT ≤ VCC.

3. Tested with outputs open (IOUT = 0).

4. RCLK and WCLK toggle at 20 MHz and data inputs switch at 10 MHz.

5. Typical ICC1 = 16 + 3.14*fS + 0.02*CL*fS (in mA) with VCC = 3.3V, tA = 25°C, fS = WCLK frequency = RCLK frequency (in MHz, using TTL levels), data switching at fS/2,

CL = capacitive load (in pF).

6. RCLK and WCLK, toggle at 20 MHz.

The following inputs should be pulled to GND: WRADD, RDADD, WADEN, RADEN, FSTR, ESTR, SCLK, SI, EXI, FXI and all Data Inputs.

The following inputs should be pulled to VCC: WEN, REN, SENI, PRS, MRS, TDI, TMS and TRST.

All other inputs are don't care, and should be pulled HIGH or LOW.

NOTE:

1 . Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause

permanent damage to the device. This is a stress rating only and functional operation

of the device at these or any other conditions above those indicated in the operational

sections of this specification is not implied. Exposure to absolute maximum rating

conditions for extended periods may affect reliability. NOTE:

1. VCC = 3.3V ± 0.15V, JEDEC JESD8-A compliant.

NOTES:

1. With output deselected, (OE ≥ VIH).

2. Characterized values, not currently tested.

CAPACITANCE (TA = +25°C, f = 1.0MHz)

Symbol Parameter(1) Conditions Max. Unit

CIN(2) Input VIN = 0V 10 pF

Capacitance

COUT(1,2) Output VOUT = 0V 10 pF

Capacitance

Symbol Parameter Min. Typ. Max. Unit

VCC(1) Supply Voltage (Com'l/Ind'l) 3.15 3.3 3.45 V

GND Supply Voltage (Com'l/Ind'l) 0 0 0 V

VIH Input High Voltage (Com'l/Ind'l) 2.0 — VCC+0.3 V

VIL Input Low Voltage (Com'l/Ind'l) — — 0.8 V

TAOperating Temperature Commercial 0 — +70 °C

TAOperating Temperature Industrial -40 — +85 °C

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Figure 2a. AC Test Load Figure 2b. Lumped Capacitive Load, Typical Derating

AC TEST LOADS

5941 drw04

50Ω

VCC/2

I/O Z0 = 50Ω

5941 drw04a

20 30 50 80 100 200

acitance

)

tCD

(Typical, ns)

Input Pulse Levels GND to 3.0V

Input Rise/Fall Times 1.5ns

Input Timing Reference Levels 1.5V

Output Reference Levels 1.5V

Output Load See Figure 2a & 2b

AC TEST CONDITIONS

OUTPUT ENABLE & DISABLE TIMING

VIH

VIL

OE &

OLZ

100mV

OHZ

100mV

Output

Normally

LOW

Output

Normally

HIGH

VOL

VOH

5941 drw04b

Output

Enable

Output

Disable

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

P R E L I M I N A R Y

AC ELECTRICAL CHARACTERISTICS

(Commercial: VCC = 3.3V ± 0.15V, TA = 0 °C to +70°C;Industrial: VCC = 3.3V ± 0.15V, TA = 40°C to +85°C; JEDEC JESD8-A compliant)

Commercial Com'l & Ind'l(1)

IDT72V51233L6 IDT72V51233L7-5

IDT72V51243L6 IDT72V51243L7-5

IDT72V51553L6 IDT72V51553L7-5

Symbol Parameter Min. Max. Min. Max. Unit

fCClock Cycle Frequency (WCLK & RCLK) — 166 — 133 M Hz

tAData Access Time 0.6 3.7 0.6 4 ns

tCLK Clock Cycle Time 6 — 7.5 — ns

tCLKH Clock High Time 2. 7 — 3. 5 — n s

tCLKL Clock Low Time 2. 7 — 3. 5 — ns

tDS Data Setup Time 2 — 2.0 — ns

tDH Data Hold Time 0.5 — 0.5 — ns

tENS Enable Setup Time 2 — 2.0 — ns

tENH Enable Hold Time 0.5 — 0.5 — ns

tRS Reset Pulse Width 10 — 10 — ns

tRSS Reset Setup Time 15 — 15 — ns

tRSR Reset Recovery Time 10 — 1 0 — ns

tPRSS Partial Reset Setup 2.0 — 2.5 — ns

tPRSH Partial Reset Hold 0.5 — 0.5 — ns

tOLZ (OE-Qn)(2) Output Enable to Output in Low-Impedance 0.6 3.7 0.6 4 ns

tOHZ(2) Output Enable to Output in High-Impedance 0.6 3.7 0.6 4 ns

tOE Output Enable to Data Output Valid 0.6 3.7 0.6 4 ns

fSClock Cycle Frequency (SCLK) — 10 — 10 MH z

tSCLK Serial Clock Cycle 100 — 100 — ns

tSCKH Serial Clock High 45 — 45 — ns

tSCKL Serial Clock Low 45 — 45 — ns

tSDS Serial Data In Setup 20 — 20 — ns

tSDH Serial Data In Hold 1. 2 — 1.2 — ns

tSENS Serial Enable Setup 20 — 20 — ns

tSENH Serial Enable Hold 1.2 — 1.2 — ns

tSDO SCLK to Serial Data Out — 20 — 2 0 ns

tSENO SCLK to Serial Enable Out — 2 0 — 2 0 ns

tSDOP Serial Data Out Propagation Delay 1.5 3.7 1.5 4 ns

tSENOP Serial Enable Propagation Delay 1.5 3.7 1.5 4 ns

tPCWQ Programming Complete to Write Queue Selection 20 — 20 — ns

tPCRQ Programming Complete to Read Queue Selection 20 20 ns

tAS Address Setup 2.5 — 3.0 — ns

tAH Address Hold 1 — 1 — ns

tWFF Write Clock to Full Flag — 3.7 — 5 ns

tROV Read Clock to Output Valid — 3.7 — 5 ns

tSTS Strobe Setup 2 — 2 — ns

tSTH Strobe Hold 0.5 — 0.5 — ns

tQS Queue Setup 2 — 2.5 — ns

tQH Queue Hold 0.5 — 0.5 — ns

tWAF WCLK to PAF flag 0. 6 3. 7 0. 6 4 n s

tRAE RCLK to PAE flag 0.6 3.7 0.6 4 ns

tPAF Write Clock to Synchronous Almost-Full Flag Bus 0.6 3.7 0.6 4 ns

tPAE Read Clock to Synchronous Almost-Empty Flag Bus 0. 6 3. 7 0.6 4 ns

NOTE:

1. Industrial temperature range product for the 7-5ns is available as a standard device. All other speed grades available by special order.

2. Values guaranteed by design, not currently tested.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

P R E L I M I N A R Y

AC ELECTRICAL CHARACTERISTICS (CONTINUED)

(Commercial: VCC = 3.3V ± 0.15V, TA = 0 °C to +70°C;Industrial: VCC = 3.3V ± 0.15V, TA = 40°C to +85°C; JEDEC JESD8-A compliant)

Commercial Com'l & Ind'l(1)

IDT72V51233L6 IDT72V51233L7-5

IDT72V51243L6 IDT72V51243L7-5

IDT72V51553L6 IDT72V51553L7-5

Symbol Parameter Min. Max. Min. Max. Unit

NOTE:

1. Industrial temperature range product for the 7-5ns is available as a standard device. All other speed grades available by special order.

2. Values guaranteed by design, not currently tested.

tPAELZ(2) RCLK to PAE Flag Bus to Low-Impedance 0. 6 3. 7 0. 6 4 n s

tPAEHZ(2) RCLK to PAE Flag Bus to High-Impedance 0. 6 3. 7 0. 6 4 n s

tPAFLZ(2) WCLK to PAF Flag Bus to Low-Impedance 0. 6 3.7 0. 6 4 n s

tPAFHZ(2) WCLK to PAF Flag Bus to High-Impedance 0. 6 3. 7 0 .6 4 n s

tFFHZ(2) WCLK to Full Flag to High-Impedance 0.6 3.7 0.6 4 ns

tFFLZ(2) WCLK to Full Flag to Low-Impedance 0.6 3.7 0.6 4 ns

tOVLZ(2) RCLK to Output Valid Flag to Low-Impedance 0.6 3.7 0.6 4 ns

tOVHZ(2) RCLK to Output Valid Flag to High-Impedance 0.6 3.7 0.6 4 ns

tFSYNC WCLK to PAF Bus Sync to Output 0.6 3.7 0.6 4 ns

tFXO WCLK to PAF Bus Expansion to Output 0. 6 3. 7 0. 6 4 n s

tESYNC RCLK to PAE Bus Sync to Output 0.6 3.7 0.6 4 ns

tEXO RCLK to PAE Bus Expansion to Output 0. 6 3.7 0. 6 4 ns

tSKEW1 SKEW time between RCLK and WCLK for FF and OV 4.5 — 5.75 — ns

tSKEW2 SKEW time between RCLK and WCLK for PAF and PAE 6 — 7.5 — ns

tSKEW3 SKEW time between RCLK and WCLK for PAF[0:7] and PAE[0:7] 6 — 7.5 — ns

tSKEW4 SKEW time between RCLK and WCLK for OV 6 — 7.5 — ns

tXIS Expansion Input Setup 1.0 — 1.3 — ns

tXIH Expansion Input Hold 0.5 — 0.5 — ns

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

FUNCTIONAL DESCRIPTION

MASTER RESET

A Master Reset is performed by toggling the MRS input from HIGH to LOW

to HIGH. During a master reset all internal Multi-Queue device setup and control

registers are initialized and require programming either serially by the user via

the serial port, or using the default settings. During a master reset the state of

the following inputs determine the functionality of the part, these pins should be

held HIGH or LOW.

FM – Flag bus Mode

IW, OW – Bus Matching options

MAST – Master Device

ID0, 1, 2 – Device ID

DFM – Programming mode, serial or default

DF – Offset value for PAE and PAF

Once a master reset has taken place, the device must be programmed either

serially or via the default method before any FIFO read/write operations can

begin.

See Figure 4, Master Reset for relevant timing.

PARTIAL RESET

A Partial Reset is a means by which the user can reset both the read and write

pointers of a single queue that has been setup within a Multi-Queue device.

Before a partial reset can take place on a queue, the respective queue must be

selected on both the read port and write port a minimum of 2 RCLK and 2 WCLK

cycles before the PRS goes LOW. The partial reset is then performed by toggling

the PRS input from HIGH to LOW to HIGH, maintaining the LOW state for at least

one WCLK and one RCLK cycle. Once a partial reset has taken place a minimum

of 3 WCLK and 3 RCLK cycles must occur before enabled writes or reads can

occur.

A Partial Reset only resets the read and write pointers of a given queue, a

partial reset will not effect the overall configuration and setup of the Multi-Queue

device and its queues.

See Figure 5, Partial Reset for relevant timing.

SERIAL PROGRAMMING

The Multi-Queue FIFO device is a fully programmable device, providing the

user with flexibility in how FIFO queues are configured in terms of the number

of queues, depth of each queue and position of the PAF/PAE flags within

respective queues. All user programming is done via the serial port after a master

reset has taken place. Internally the Multi-Queue device has setup registers

which must be serially loaded, these registers contain values for every queue

within the device, such as the depth and PAE/PAF offset values. The

IDT72V51233/72V51243/72V51253 devices are capable of up to 4 queues

and therefore contain 4 sets of registers for the setup of each queue.

During a Master Reset if the DFM (Default Mode) input is LOW, then the device

will require serial programming by the user. It is recommended that the user

utilize a ‘C’ program provided by IDT, this program will prompt the user for all

information regarding the Multi-Queue setup. The program will then generate

a serial bit stream which should be serially loaded into the device via the serial

port. For the IDT72V51233/72V51243/72V51253 devices the serial program-

ming requires a total number of serially loaded bits per device, (SCLK cycles with

SENI enabled), calculated by: 19+(Qx72) where Q is the number of queues the

user wishes to setup within the device. Please refer to the separate Application

Note, AN-303 for recommended control of the serial programming port.

Once the master reset is complete and MRS is HIGH, the device can be

serially loaded. Data present on the SI (serial in), input is loaded into the serial

port on a rising edge of SCLK (serial clock), provided that SENI (serial in

enable), is LOW. Once serial programming of the device has been successfully

completed the device will indicate this via the SENO (serial output enable) going

active, LOW. Upon detection of completion of programming, the user should

cease all programming and take SENI inactive, HIGH. Note, SENO follows SENI

once programming of a device is complete. Therefore, SENO will go LOW after

programming provided SENI is LOW, once SENI is taken HIGH again, SENO

will also go HIGH. The operation of the SO output is similar, when programming

of a given device is complete, the SO output will follow the SI input.

If devices are being used in expansion mode the serial ports of devices should

be cascaded. The user can load all devices via the serial input port control pins,

SI & SENI, of the first device in the chain. Again, the user may utilize the ‘C’

program to generate the serial bit stream, the program prompting the user for

the number of devices to be programmed. The SENO and SO (serial out) of

the first device should be connected to the SENI and SI inputs of the second

device respectively and so on, with the SENO & SO outputs connecting to the

SENI & SI inputs of all devices through the chain. All devices in the chain should

be connected to a common SCLK. The serial output port of the final device should

be monitored by the user. When SENO of the final device goes LOW, this

indicates that serial programming of all devices has been successfully com-

pleted. Upon detection of completion of programming, the user should cease all

programming and take SENI of the first device in the chain inactive, HIGH.

As mentioned, the first device in the chain has its serial input port controlled

by the user, this is the first device to have its internal registers serially loaded

by the serial bit stream. When programming of this device is complete it will take

its SENO output LOW and bypass the serial data loaded on the SI input to its

SO output. The serial input of the second device in the chain is now loaded with

the data from the SO of the first device, while the second device has its SENI

input LOW. This process continues through the chain until all devices are

programmed and the SENO of the final device goes LOW.

Once all serial programming has been successfully completed, normal

operations, (queue selections on the read and write ports) may begin. When

connected in expansion mode, the IDT72V51233/72V51243/72V51253 de-

vices require a total number of serially loaded bits per device to complete serial

programming, (SCLK cycles with SENI enabled), calculated by: n[19+(Qx72)]

where Q is the number of queues the user wishes to setup within the device,

where n is the number of devices in the chain.

See Figure 6, Serial Port Connection and Figure 7, Serial Programming for

connection and timing information.

DEFAULT PROGRAMMING

During a Master Reset if the DFM (Default Mode) input is HIGH the Multi-

Queue device will be configured for default programming, (serial programming

is not permitted). Default programming provides the user with a simpler,

however limited means by which to setup the Multi-Queue FIFO device, rather

than using the serial programming method. The default mode will configure a

Multi-Queue device such that the maximum number of queues possible are

setup, with all of the parts available memory blocks being allocated equally

between the queues. The values of the PAE/PAF offsets is determined by the

state of the DF (default) pin during a master reset.

For the IDT72V51233/72V51243/72V51253 devices the default mode will

setup 4 queues, each queue configured as follows: For the IDT72V51233 with

x9 input and x9 output ports, 16,384 x 9. If one or both ports is x18, 8,192 x

18. For the IDT72V51243 with x9 input and x9 output ports, 32,768 x 9. If one

or both ports is x18, 16,384 x 18. For the IDT72V51253 with x9 input and x9

output ports, 65,536 x 9. If one or both ports is x18, 32,768 x 18. For both devices

the value of the PAE/PAF offsets is determined at master reset by the state of

the DF input. If DF is LOW then both the PAE & PAF offset will be 8, if HIGH then

the value is 128.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

When configuring the IDT72V51233/72V51243/72V51253 devices in de-

fault mode the user simply has to apply WCLK cycles after a master reset, until

SENO goes LOW, this signals that default programming is complete. These clock

cycles are required for the device to load its internal setup registers. When a

single Multi-Queue device is used, the completion of device programming is

signaled by the SENO output of a device going from HIGH to LOW. Note, that

SENI must be held LOW when a device is setup for default programming mode.

When Multi-Queue devices are connected in expansion mode, the SENI of

the first device in a chain can be held LOW. The SENO of a device should connect

to the SENI of the next device in the chain. The SENO of the final device is used

to indicate that default programming of all devices is complete. When the final

SENO goes LOW normal operations may begin. Again, all devices will be

programmed with their maximum number of queues and the memory divided

equally between them. Please refer to Figure 8, Default Programming.

WRITE QUEUE SELECTION & WRITE OPERATION

The IDT72V51233/72V51243/72V51253 Multi-Queue FIFO devices have

up to 4 FIFO queues that data can be written into via a common write port using

the data inputs, Din, write clock, WCLK and write enable, WEN. The queue

address present on the write address bus, WRADD during a rising edge on

WCLK while write address enable, WADEN is HIGH, is the queue selected for

write operations. The state of WEN is don’t care during the write queue selection

cycle. The queue selection only has to be made on a single WCLK cycle, this

will remain the selected queue until another queue is selected, the selected

queue is always the last queue selected.

The write port is designed such that 100% bus utilization can be obtained.

This means that data can be written into the device on every WCLK rising edge

including the cycle that a new queue is being addressed. When a new queue

is selected for write operations the address for that queue must be present on

the WRADD bus during a rising edge of WCLK provided that WADEN is HIGH.

A queue to be written to need only be selected on a single rising edge of WCLK.

All subsequent writes will be written to that queue until a new queue is selected.

A minimum of 2 WCLK cycles must occur between queue selections on the write

port. On the next WCLK rising edge the write port discrete full flag will update

to show the full status of the newly selected queue. On the second rising edge

of WCLK, data present on the data input bus, Din can be written into the newly

selected FIFO queue provided that WEN is LOW and the new queue is not full.

The cycle of the queue selection and the next cycle will continue to write data

present on the data input bus, Din into the previous queue provided that WEN

is active LOW.

If WEN is HIGH, inactive for these 2 clock cycles, then data will not be written

in to the previous queue.

If the newly selected queue is full at the point of its selection, then writes to that

queue will be prevented, a full queue cannot be written into.

In the 4 queue Multi-Queue device the WRADD address bus is 5 bits wide.

The least significant 2 bits are used to address one of the 4 available queues

within a single Multi-Queue device. The most significant 3 bits are used when

a device is connected in expansion mode, up to 8 devices can be connected

in expansion, each device having its own 3 bit address. The selected device

is the one for which the address matches a 3 bit ID code, which is statically setup

on the ID pins, ID0, ID1, and ID2 of each individual device.

Note, the WRADD bus is also used in conjunction with FSTR (almost full flag

bus strobe), to address the almost full flag bus of a respective device during direct

mode of operation.

Refer to Table 1, for Write Address bus arrangement. Also, refer to Figure

9, Write Queue Select, Write Operation and Full flag Operation and Figure

11, Full Flag Timing Expansion Mode for timing diagrams.

TABLE 1 — WRITE ADDRESS BUS, WRADD[4:0]

Operation WCLK WADEN FSTR WRADD[4:0]

Write Queue

Select

Device Select

(Compared to

ID0,1,2)

Write Queue Address

(2 bits = 4 Queues)

432 10

Device Select

(Compared to

ID0,1,2)

PAFn Flag Bus

Device Select

5941 drw05

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

READ QUEUE SELECTION & READ OPERATION

The Multi-Queue FIFO device has up to 4 FIFO queues that data is read from

via a common read port using the data outputs, Qout, read clock, RCLK and

read enable, REN. An output enable, OE control pin is also provided to allow

High-Impedance selection of the Qout data outputs. The Multi-Queue device

read port operates in a mode similar to “First Word Fall Through” on a traditional

IDT FIFO, but with the added feature of data output pipelining. This data

pipelining on the output port allows the user to achieve 100% bus utilization,

which is the ability to read out a data word on every rising edge of RCLK

regardless of whether a new queue is being selected for read operations.

The queue address present on the read address bus, RDADD during a rising

edge on RCLK while read address enable, RADEN is HIGH, is the queue

selected for read operations. A queue to be read from need only be selected

on a single rising edge of RCLK. All subsequent reads will be read from that

queue until a new queue is selected. A minimum of 2 RCLK cycles must occur

between queue selections on the read port. Data from the newly selected queue

will be present on the Qout outputs after 2 RCLK cycles plus an access time,

provided that OE is active, LOW. On the same RCLK rising edge that the new

queue is selected, data can still be read from the previously selected queue,

provided that REN is LOW, active and the previous queue is not empty on the

following rising edge of RCLK a word will be read from the previously selected

queue regardless of REN due to the fall through operation, (provided the queue

is not empty). Remember that OE allows the user to place the Qout, data output

bus into High-Impedance and the data can be read onto the output register

regardless of OE.

When a queue is selected on the read port, the next word available in that

queue (provided that the queue is not empty), will fall through to the output

the new data being available, data can still be read from the previous queue,

provided that the queue is not empty. At the point of queue selection, the 2-stage

internal data pipeline is loaded with the last word from the previous queue and

the next word from the new queue, both these words will fall through to the output

provides the user with 100% bus utilization, but brings about the possibility that

a “NULL” queue may be required within a Multi-Queue device. Null queue

operation is discussed in the next section on.

If an empty queue is selected for read operations on the rising edge of RCLK,

on the same RCLK edge and the following RCLK edge, 2 final reads will be made

from the previous queue, provided that REN is active, LOW. On the next RCLK

rising edge a read from the new queue will not occur, because the queue is

empty. The last word in the data output register (from the previous queue), will

remain there, but the output valid flag, OV will go HIGH, to indicate that the data

present is no longer valid.

The RDADD bus is also used in conjunction with ESTR (almost empty flag

bus strobe), to address the almost empty flag bus of a respective device during

direct mode of operation. In the 4 queue Multi-Queue device the RDADD

address bus is 6 bits wide. The least significant 2 bits are used to address one

of the 4 available queues within a single Multi-Queue device. The 3rd least

significant bit is used to select a "Null" Queue. During a Null-Q selection the 2

LSB's are don't care. The Null-Q is seen as an empty queue on the read port.

Null-Q operation is discussed in more detail in a separate section. The most

significant 3 bits are used when a device is connected in expansion mode, up

to 8 devices can be connected in expansion, each device having its own 3 bit

address. The selected device is the one for which the address matches a 3 bit

ID code, which is statically setup on the ID pins, ID0, ID1, and ID2 of each

individual device.

Refer to Table 2, for Read Address bus arrangement. Also, refer to Figures

12,14 & 15 for read queue selection and read port operation timing diagrams.

Operation RCLK RADEN ESTR RDADD[5:0]

Read Queue

Select

Device Select

(Compared to

ID0,1,2)

Read Queue Address

(2 bits = 4 Queues)

543 2 10

Device Select

(Compared to

ID0,1,2)

Flag Bus Device

Selection

5941 drw06

Null-Q

Select Pin

TABLE 2 — READ ADDRESS BUS, RDADD[5:0]

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

NULL QUEUE OPERATION (OF THE READ PORT)

Pipelining of data to the output port enables the device to provide 100% bus

utilization, data can be read out of the Multi-Queue FIFO on every RCLK cycle

regardless of queue switches or other operations. The device architecture is

such that the pipeline is constantly filled with the next words in a selected queue

to be read out, again providing 100% bus utilization and high speed operation.

This type of architecture does assume that the user is constantly switching

queues such that during a queue switch, the last data words required from the

previous queue are forced through the pipeline to the output.

To put it another way, if a user is reading from a queue and wishes to stop

reading from that queue and do nothing, the pipe will have the next word in that

queue available in the pipeline. If the user now switches to another queue the

first data out of the pipe will be the word from the previous queue. If the user has

no new queue to switch to, the next data word from the current queue will be

sitting in the pipeline, this word may need to be forced out through the pipe. Note,

that if reads cease at the empty boundary of a queue, then the last word will

automatically be forced through the pipeline to the outputs.

If the user does not want to bring words from a queue into the pipeline after

a read operation within a specific queue has ended, then to force the last required

word out of the pipe, a user has 2 options open to them, that is, a means by which

to force data out of the pipe at the end of read operations without filling the pipeline

with new data.

The first of these 2 options is to “double pump” data when writing the data into

the given FIFO queue. This essentially means performing 2 writes of the last

word of a given section of data to be read out. This provides a means by which

when the read port stops reading the pipeline is filled with the same word twice

and so the last word is read out. If a queue switch occurs, the first word out will

be the double written word from the previous queue and should be ignored.

This option assumes that the user is both writing and reading data with known

sizes of packets (a packet is made up of data words). So that the last word (write)

within a packet can be written twice (double pumped). This option however

means that the user gives up the 100% bus utilization feature of the Multi-Queue

device, the double pump takes up the bus for a single RCLK cycle.

Therefore a second option is available to the user, this is the “Null Q” select,

this option allows the user to force the last required data words from a queue

through the pipeline, whilst maintaining 100% bus utilization. This provides a

means by which the user can force data out of the pipeline when read operations

from a queue have ceased and there are no new queues that need to be

switched over to and read from. The Null-Q is selected via read port address

space RDADD[2]. The RDADD[5:0] bus should be addressed with xxx1xx,

this address is the Null-Q.

The null queue can now be "switched" to by the user when no further reads

are required from a previously selected queue. The queue switch to the null

queue will force the data in the pipeline to be forced through to the outputs. The

device can now remain with the null queue selected until a further queue change

is made to a queue containing data available for read operations.

Note, If the user switches the read port to the null queue, this queue is seen

as and treated as an empty queue, therefore after switching to the null queue

the last word from the previous queue will remain on the output register and the

OV flag will go HIGH, data not valid.

The null queue operation is only a possible requirement on the read port of

the Multi-Queue, a means by which to force data through the output pipeline.

Null Q selection and operation has no meaning or advantage on the write port

of the device. A Null Q address should never be selected on the write port.

See Figure 16, Read Operation and Null Queue Selection and Figure 17,

Null Queue Flow Diagram for a detailed timing diagrams that shows how null

queue selection can be implemented.

BUS MATCHING OPERATION

Bus Matching operation between the input port and output port is available.

During a master reset of the Multi-Queue the state of the two setup pins, IW (Input

Width) and OW (Output Width) determine the input and output port bus widths

as per the selections shown in Table 3, “Bus Matching Set-up”. 9 bit bytes or

18 bit words can be written into and read form the FIFO queues. When writing

to or reading from the Multi-Queue in a bus matching mode, the device orders

data in a “Little Endian” format. See Figure 3, Bus Matching Byte Arrangement

for details.

The Full flag and Almost Full flag operation is always based on writes and

reads of data widths determined by the write port width. For example, if the input

port is x18 and the output port is x9, then two data reads from a full queue will

be required to cause the full flag to go HIGH (queue not full). Conversely, the

Output Valid flag and Almost Empty flag operations are always based on writes

and reads of data widths determined by the read port. For example, if the input

port is x9 and the output port is x18, two write operations will be required to cause

the output valid flag of an empty queue to go LOW, output valid (queue is not

empty).

Note, that the input port serves all queues within a device, as does the output

port, therefore the input bus width to all queues is equal (determined by the input

port size) and the output bus width from all queues is equal (determined by the

output port size).

TABLE 3 — BUS-MATCHING SET-UP

FULL FLAG OPERATION

The Multi-Queue FIFO device provides a single Full Flag output, FF. The

FF flag output provides a full status of the FIFO queue currently selected on the

write port for write operations. Internally the Multi-Queue FIFO monitors and

maintains a status of the full condition of all queues within it, however only the

queue that is selected for write operations has its full status output to the FF flag.

This dedicated flag is often referred to as the “active queue full flag”.

When queue switches are being made on the write port, the FF flag output

will switch to the new queue and provide the user with the new queue status,

on the cycle after a new queue selection is made. The user then has a full status

for the new queue one cycle ahead of the WCLK rising edge that data can be

written into the new queue. That is, a new queue can be selected on the write

port via the WRADD bus, WADEN enable and a rising edge of WCLK. On the

next rising edge of WCLK, the FF flag output will show the full status of the newly

selected queue. On the second rising edge of WCLK following the queue

selection, data can be written into the newly selected queue provided that data

and enable setup & hold times are met.

Note, the FF flag will provide status of a newly selected queue one WCLK

cycle after queue selection, which is one cycle before data can be written to that

queue. This prevents the user from writing data to a FIFO queue that is full,

(assuming that a queue switch has been made to a queue that is actually full).

The FF flag is synchronous to the WCLK and all transitions of the FF flag occur

based on a rising edge of WCLK. Internally the Multi-Queue device monitors

and keeps a record of the full status for all queues. It is possible that the status

IW OW Write Port Read Port

0 0 x18 x18

0 1 x18 x9

1 0 x9 x18

1 1 x9 x9

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

of a FF flag maybe changing internally even though that flag is not the active

queue flag (selected on the write port). A queue selected on the read port may

experience a change of its internal full flag status based on read operations.

See Figure 9, Write Queue Select, Write Operation and Full Flag Operation

and Figure 11, Full Flag Timing in Expansion Mode for timing information.

EXPANSION MODE - FULL FLAG OPERATION

When Multi-Queue devices are connected in Expansion mode the FF flags

of all devices should be connected together, such that a system controller

monitoring and managing the Multi-Queue devices write port only looks at a

single FF flag (as opposed to a discrete FF flag for each device). This FF flag

is only pertinent to the FIFO queue being selected for write operations at that

time. Remember, that when in expansion mode only one Multi-Queue device

can be written to at any moment in time, thus the FF flag provides status of the

active queue on the write port.

This connection of flag outputs to create a single flag requires that the FF flag

output have a High-Impedance capability, such that when a queue selection is

made only a single device drives the FF flag bus and all other FF flag outputs

connected to the FF flag bus are placed into High-Impedance. The user does

not have to select this High-Impedance state, a given Multi-Queue FIFO device

will automatically place its FF flag output into High-Impedance when none of its

queues are selected for write operations.

When queues within a single device are selected for write operations, the FF

flag output of that device will maintain control of the FF flag bus. Its FF flag will

simply update between queue switches to show the respective queue full status.

The Multi-Queue device places its FF flag output into High-Impedance based

on the 3 bit ID code found in the 3 most significant bits of the write queue address

bus, WRADD. If the 3 most significant bits of WRADD match the 3 bit ID code setup

on the static inputs, ID0, ID1 and ID2 then the FF flag output of the respective

device will be in a Low-Impedance state. If they do not match, then the FF flag

output of the respective device will be in a High-Impedance state. See Figure

11, Full Flag Timing in Expansion Mode for details of flag operation, including

when more than one device is connected in expansion.

OUTPUT VALID FLAG OPERATION

The Multi-Queue FIFO device provides a single Output Valid flag output, OV.

The OV provides an empty status or data output valid status for the data word

currently available on the output register of the read port. The rising edge of an

RCLK cycle that places new data onto the output register of the read port, also

updates the OV flag to show whether or not that new data word is actually valid.

Internally the Multi-Queue FIFO monitors and maintains a status of the empty

condition of all queues within it, however only the queue that is selected for read

operations has its output valid (empty) status output to the OV flag, giving a valid

status for the word being read at that time.

The nature of the first word fall through operation means that when the last

data word is read from a selected queue, the OV flag will go HIGH on the next

enabled read, that is, on the next rising edge of RCLK while REN is LOW.

When queue switches are being made on the read port, the OV flag will switch

to show status of the new queue in line with the data output from the new queue.

When a queue selection is made the first data from that queue will appear on

the Qout data outputs 2 RCLK cycles later, the OV will change state to indicate

validity of the data from the newly selected queue on this 2nd RCLK cycle also.

The previous cycles will continue to output data from the previous queue and

the OV flag will indicate the status of those outputs. Again, the OV flag always

indicates status for the data currently present on the output register.

The OV flag is synchronous to the RCLK and all transitions of the OV flag occur

based on a rising edge of RCLK. Internally the Multi-Queue device monitors

and keeps a record of the output valid (empty) status for all queues. It is possible

that the status of an OV flag may be changing internally even though that

respective flag is not the active queue flag (selected on the read port). A queue

selected on the write port may experience a change of its internal OV flag status

based on write operations, that is, data may be written into that queue causing

it to become “not empty”.

See Figure 12, Read Queue Select, Read Operation and Figure 13, Output

Valid Flag Timing for details of the timing.

EXPANSION MODE – OUTPUT VALID FLAG OPERATION

When Multi-Queue devices are connected in Expansion mode, the OV flags

of all devices should be connected together, such that a system controller

monitoring and managing the Multi-Queue devices read port only looks at a

single OV flag (as opposed to a discrete OV flag for each device). This OV flag

is only pertinent to the FIFO queue being selected for read operations at that

time. Remember, that when in expansion mode only one Multi-Queue device

can be read from at any moment in time, thus the OV flag provides status of the

active queue on the read port.

This connection of flag outputs to create a single flag requires that the OV flag

output have a High-Impedance capability, such that when a queue selection is

made only a single device drives the OV flag bus and all other OV flag outputs

connected to the OV flag bus are placed into High-Impedance. The user does

not have to select this High-Impedance state, a given Multi-Queue FIFO device

will automatically place its OV flag output into High-Impedance when none of its

queues are selected for read operations.

When queues within a single device are selected for read operations, the OV

flag output of that device will maintain control of the OV flag bus. Its OV flag will

simply update between queue switches to show the respective queue output

valid status.

The Multi-Queue device places its OV flag output into High-Impedance based

on the 3 bit ID code found in the 3 most significant bits of the read queue address

bus, RDADD. If the 3 most significant bits of RDADD match the 3 bit ID code setup

on the static inputs, ID0, ID1 and ID2 then the OV flag output of the respective

device will be in a Low-Impedance state. If they do not match, then the OV flag

output of the respective device will be in a High-Impedance state. See Figure

13, Output Valid Flag Timing for details of flag operation, including when more

than one device is connected in expansion.

ALMOST FULL FLAG

As previously mentioned the Multi-Queue FIFO device provides a single

Programmable Almost Full flag output, PAF. The PAF flag output provides a

status of the almost full condition for the active queue currently selected on the

write port for write operations. Internally the Multi-Queue FIFO monitors and

maintains a status of the almost full condition of all queues within it, however only

the queue that is selected for write operations has its full status output to the PAF

flag. This dedicated flag is often referred to as the “active queue almost full flag”.

The position of the PAF flag boundary within a FIFO queue can be at any point

within that queues depth. This location can be user programmed via the serial

port or one of the default values (8 or 128) can be selected if the user has

performed default programming.

As mentioned, every queue within a Multi-Queue device has its own almost

full status, when a queue is selected on the write port, this status is output via the

PAF flag. The PAF flag value for each queue is programmed during Multi-

Queue device programming (along with the number of queues, queue depths

and almost empty values). The PAF offset value, m, for a respective queue can

be programmed to be anywhere between ‘0’ and ‘D’, where ‘D’ is the total

memory depth for that queue. The PAF value of different queues within the same

device can be different values.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

When queue switches are being made on the write port, the PAF flag output

will switch to the new queue and provide the user with the new queue status,

on the second cycle after a new queue selection is made, on the same WCLK

cycle that data can actually be written to the new queue. That is, a new queue

can be selected on the write port via the WRADD bus, WADEN enable and

a rising edge of WCLK. On the second rising edge of WCLK following a queue

selection, the PAF flag output will show the full status of the newly selected

queue. The PAF is flag output is double register buffered, so when a write

operation occurs at the almost full boundary causing the selected queue status

to go almost full the PAF will go LOW 2 WCLK cycles after the write. The same

is true when a read occurs, there will be a 2 WCLK cycle delay after the read

operation.

So the PAF flag delays are:

from a write operation to PAF flag LOW is 2 WCLK + tWAF

The delay from a read operation to PAF flag HIGH is tSKEW2 + WCLK + tWAF

Note, if tSKEW is violated there will be one added WCLK cycle delay.

The PAF flag is synchronous to the WCLK and all transitions of the PAF flag

occur based on a rising edge of WCLK. Internally the Multi-Queue device

monitors and keeps a record of the almost full status for all queues. It is possible

that the status of a PAF flag maybe changing internally even though that flag

is not the active queue flag (selected on the write port). A queue selected on

the read port may experience a change of its internal almost full flag status based

on read operations. The Multi-Queue FIFO device also provides a duplicate

of the PAF flag on the PAF[3:0] flag bus, this will be discussed in detail in a later

section of the data sheet.

See Figures 18 and 19 for Almost Full flag timing and queue switching.

ALMOST EMPTY FLAG

As previously mentioned the Multi-Queue FIFO device provides a single

Programmable Almost Empty flag output, PAE. The PAE flag output provides

a status of the almost empty condition for the active queue currently selected

on the read port for read operations. Internally the Multi-Queue FIFO monitors

and maintains a status of the almost empty condition of all queues within it,

however only the queue that is selected for read operations has its empty status

output to the PAE flag. This dedicated flag is often referred to as the “active

queue almost empty flag”. The position of the PAE flag boundary within a FIFO

queue can be at any point within that queues depth. This location can be user

programmed via the serial port or one of the default values (8 or 128) can be

selected if the user has performed default programming.

As mentioned, every queue within a Multi-Queue device has its own almost

empty status, when a queue is selected on the read port, this status is output via

the PAE flag. The PAE flag value for each queue is programmed during Multi-

Queue device programming (along with the number of queues, queue depths

and almost full values). The PAE offset value, n, for a respective queue can be

programmed to be anywhere between ‘0’ and ‘D’, where ‘D’ is the total memory

depth for that queue. The PAE value of different queues within the same device

can be different values.

When queue switches are being made on the read port, the PAE flag output

will switch to the new queue and provide the user with the new queue status,

on the second cycle after a new queue selection is made, on the same RCLK

cycle that data actually falls through to the output register from the new queue.

That is, a new queue can be selected on the read port via the RDADD bus,

RADEN enable and a rising edge of RCLK. On the second rising edge of RCLK

following a queue selection, the data word from the new queue will be available

at the output register and the PAE flag output will show the empty status of the

newly selected queue. The PAE is flag output is double register buffered, so

when a read operation occurs at the almost empty boundary causing the

selected queue status to go almost empty the PAE will go LOW 2 RCLK cycles

after the read. The same is true when a write occurs, there will be a 2 RCLK

cycle delay after the write operation.

So the PAE flag delays are:

from a read operation to PAE flag LOW is 2 RCLK + tRAE

The delay from a write operation to PAE flag HIGH is tSKEW2 + RCLK + tRAE

Note, if tSKEW is violated there will be one added RCLK cycle delay.

The PAE flag is synchronous to the RCLK and all transitions of the PAE flag

occur based on a rising edge of RCLK. Internally the Multi-Queue device

monitors and keeps a record of the almost empty status for all queues. It is possible

that the status of a PAE flag maybe changing internally even though that flag is

not the active queue flag (selected on the read port). A queue selected on the

write port may experience a change of its internal almost empty flag status based

on write operations. The Multi-Queue FIFO device also provides a duplicate

of the PAE flag on the PAE[3:0] flag bus, this will be discussed in detail in a later

section of the data sheet.

See Figures 20 and 21 for Almost Empty flag timing and queue switching.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

TABLE 4 — FLAG OPERATION BOUNDARIES & TIMING

Output Valid, OV Flag Boundary

I/O Set-Up OV Boundary Condition

In18 to out18 or In9 to out9 OV Goes LOW after 1st Write

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In18 to out9) OV Goes LOW after 1st Write

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In9 to out18 OV Goes LOW after 2nd Write

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

NOTE:

1. OV Timing

Assertion:

Write to OV LOW: tSKEW1 + RCLK + tROV

If tSKEW1 is violated there may be 1 added clock: tSKEW1 + 2 RCLK + tROV

De-assertion:

Read Operation to OV HIGH: tROV

NOTE:

D = FIFO Queue Depth

FF Timing

Assertion:

Write Operation to FF LOW: tWFF

De-assertion:

Read to FF HIGH: tSKEW1 + tWFF

If tSKEW1 is violated there may be 1 added clock: tSKEW1+WCLK +tWFF

Full Flag, FF Boundary

I/O Set-Up FF Boundary Condition

In18 to out18 or In9 to out9 FF Goes LOW after D+1 Writes

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In18 to out18 or In9 to out9 FF Goes LOW after D Writes

(Write port only selected for queue (see note below for timing)

when the 1st Word is written in)

In18 to out9 FF Goes LOW after D Writes

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In18 to out9 FF Goes LOW after D Writes

(Write port only selected for queue (see note below for timing)

when the 1st Word is written in)

In9 to out18 FF Goes LOW after ([D+1] x 2) Writes

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In9 to out18 FF Goes LOW after (D x 2) Writes

(Write port only selected for queue (see note below for timing)

when the 1st Word is written in)

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

TABLE 4 — FLAG OPERATION BOUNDARIES & TIMING (CONTINUED)

NOTE:

n = Almost Empty Offset value.

Default values: if DF is LOW at Master Reset then n = 8

if DF is HIGH at Master Reset then n = 128

PAEn Timing

Assertion: Read Operation to PAEn LOW: 2 RCLK* + tPAE

De-assertion: Write to PAEn HIGH: tSKEW3 + RCLK* + tPAE

If tSKEW3 is violated there may be 1 added clock: tSKEW3 + 2 RCLK* + tPAE

* If a queue switch is occurring on the read port at the point of flag assertion there may

be one additional RCLK clock cycle delay.

Programmable Almost Empty Flag Bus, PAEn Boundary

I/O Set-Up PAEn Boundary Condition

In18 to out18 or In9 to out9 PAEn Goes HIGH after

(Both ports selected for same queue when the 1st n+2 Writes

Word is written in until the boundary is reached) (see note below for timing)

In18 to out18 or In9 to out9 PAEn Goes HIGH after

(Write port only selected for same queue when the n+1 Writes

1st Word is written in until the boundary is reached) (see note below for timing)

In18 to out9 PAEn Goes HIGH after n+1

Writes (see below for timing)

In9 to out18 PAEn Goes HIGH after

(Both ports selected for same queue when the 1st ([n+2] x 2) Writes

Word is written in until the boundary is reached) (see note below for timing)

In9 to out18 PAEn Goes HIGH after

(Write port only selected for same queue when the ([n+1] x 2) Writes

1st Word is written in until the boundary is reached) (see note below for timing)

Programmable Almost Full Flag, PAF & PAFn Bus Boundary

I/O Set-Up PAF & PAFn Boundary

In18 to out18 or In9 to out9 PAF/PAFn Goes LOW after

(Both ports selected for same queue when the 1st D+1-m Writes

Word is written in until the boundary is reached) (see note below for timing)

In18 to out18 or In9 to out9 PAF/PAFn Goes LOW after

(Write port only selected for same queue when the D-m Writes

1st Word is written in until the boundary is reached) (see note below for timing)

In18 to out9 PAF/PAFn Goes LOW after

D-m Writes (see below for timing)

In9 to out18 PAF/PAFn Goes LOW after

([D+1-m] x 2) Writes

(see note below for timing)

NOTE:

D = FIFO Queue Depth

m = Almost Full Offset value.

Default values: if DF is LOW at Master Reset then m = 8

if DF is HIGH at Master Reset then m= 128

PAF Timing

Assertion: Write Operation to PAF LOW: 2 WCLK + tWAF

De-assertion: Read to PAF HIGH: tSKEW2 + WCLK + tWAF

If tSKEW2 is violated there may be 1 added clock: tSKEW2 + 2 WCLK + tWAF

PAFn Timing

Assertion: Write Operation to PAFn LOW: 2 WCLK* + tPAF

De-assertion: Read to PAFn HIGH: tSKEW3 + WCLK* + tPAF

If tSKEW3 is violated there may be 1 added clock: tSKEW3 + 2 WCLK* + t PAF

* If a queue switch is occurring on the write port at the point of flag assertion there may

be one additional WCLK clock cycle delay.

NOTE:

n = Almost Empty Offset value.

Default values: if DF is LOW at Master Reset then n = 8

if DF is HIGH at Master Reset then n = 128

PAE Timing

Assertion: Read Operation to PAE LOW: 2 RCLK + tRAE

De-assertion: Write to PAE HIGH: tSKEW2 + RCLK + tRAE

If tSKEW2 is violated there may be 1 added clock: tSKEW2 + 2 RCLK + tRAE

Programmable Almost Empty Flag, PAE Boundary

I/O Set-Up PAE Assertion

In18 to out18 or In9 to out9 PAE Goes HIGH after n+2

(Both ports selected for same queue when the 1st Writes

Word is written in until the boundary is reached) (see note below for timing)

In18 to out9 PAE Goes HIGH after n+1

(Both ports selected for same queue when the 1st Writes

Word is written in until the boundary is reached) (see note below for timing)

In9 to out18 PAE Goes HIGH after

(Both ports selected for same queue when the 1st ([n+2] x 2) Writes

Word is written in until the boundary is reached) (see note below for timing)

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

PAFn FLAG BUS OPERATION

The IDT72V51233/72V51243/72V51253 Multi-Queue FIFO device can be

configured for up to 4 FIFO queues, each queue having its own almost full status.

An active queue has its flag status output to the discrete flags, FF and PAF, on

the write port. Queues that are not selected for a write operation can have their

PAF status monitored via the PAFn bus. The PAFn flag bus is 4 bits wide, so

that all 4 queues can have their status output to the bus. When a single

Multi-Queue device is used anywhere from 1 to 4 queues may be set-up within

the part, each queue having its own dedicated PAF flag output on the PAFn bus.

Queues 1 through 4 have their PAF status to PAF[0] through PAF[3]

respectively. If less than 4 queues are used then only the associated PAFn

outputs will be required, unused PAFn outputs will be don’t care outputs. When

devices are connected in expansion mode the PAFn flag bus can also be

expanded beyond 4 bits to produce a wider PAFn bus that encompasses all

queues.

Alternatively, the 4 bit PAFn flag bus of each device can be connected together

to form a single 4 bit bus, i.e. PAF[0] of device 1 will connect to PAF[0] of device

2 etc. When connecting devices in this manner the PAFn can only be driven

by a single device at any time, (the PAFn outputs of all other devices must be

in high impedance state). There are two methods by which the user can select

which device has control of the bus, these are “Direct” (Addressed) mode or

“Polled” (Looped) mode, determined by the state of the FM (flag Mode) input

during a Master Reset.

PAFn BUS EXPANSION - DIRECT MODE

If FM is LOW at Master Reset then the PAFn bus operates in Direct

(addressed) mode. In direct mode the user can address the device they require

to control the PAFn bus. The address present on the 3 most significant bits of

the WRADD[4:0] address bus with FSTR (PAF flag strobe), HIGH will be

selected as the device on a rising edge of WCLK. So to address the first device

in a bank of devices the WRADD[4:0] address should be “000xx” the second

device “001xx” and so on. The 3 most significant bits of the WRADD[4:0] address

bus correspond to the device ID inputs ID[2:0]. The PAFn bus will change status

to show the new device selected 1 WCLK cycle after device selection. Note, that

if a read or write operation is occurring to a specific queue, say queue ‘x’ on

the same cycle as a PAFn bus switch to the device containing queue ‘x’, then

there may be an extra WCLK cycle delay before that queues status is correctly

shown on the respective output of the PAFn bus. However, the “active” PAF

flag will show correct status at all times.

Devices can be selected on consecutive WCLK cycles, that is the device

controlling the PAFn bus can change every WCLK cycle. Also, data present

on the input bus, Din, can be written into a FIFO queue on the same WLCK rising

edge that a device is being selected on the PAFn bus, the only restriction being

that a write queue selection and PAFn bus selection cannot be made on the same

cycle.

PAFn BUS EXPANSION– POLLED MODE

If FM is HIGH at Master Reset then the PAFn bus operates in Polled (Looped)

mode. In polled mode the PAFn bus automatically cycles through the devices

connected in expansion. In expansion mode one device will be set as the

Master, MAST input tied HIGH, all other devices will have MAST tied LOW. The

master device is the first device to take control of the PAFn bus and place the

PAF status of its queues onto the bus on the first rising edge of WCLK after the

MRS input goes HIGH once a Master Reset is complete. The FSYNC (PAF sync

pulse) output of the first device (master device), will be HIGH for one cycle of

WCLK indicating that it is has control of the PAFn bus for that cycle.

The device also passes a “token” onto the next device in the chain, the next

device assuming control of the PAFn bus on the next WCLK cycle. This token

passing is done via the FXO outputs and FXI inputs of the devices (“PAFn

Expansion Out” and “PAFn Expansion In”). The FXO output of the first device

connecting to the FXI input of the second device in the chain, the FXO of the

second device connects to the FXI of the third device and so on. The FXO of

the final device in a chain connects to the FXI of the first device, so that once the

PAFn bus has cycled through all devices control is again passed to the first

device. The FXO output of a device will be HIGH for the WCLK cycle it has control

of the bus.

Please refer to Figure 24,

PAF

n Bus – Polled Mode for timing information.

PAEn FLAG BUS OPERATION

The IDT72V51233/72V51243/72V51253 Multi-Queue FIFO device can be

configured for up to 4 FIFO queues, each queue having its own almost empty

status. An active queue has its flag status output to the discrete flags, OV and PAE,

on the read port. Queues that are not selected for a read operation can have

their PAE status monitored via the PAEn bus. The PAEn flag bus is 4 bits wide,

so that all 4 queues can have their status output to the bus.

When a single Multi-Queue device is used anywhere from 1 to 4 queues may

be set-up within the part, each queue having its own dedicated PAEn flag output

on the PAEn bus. Queues 1 through 4 have their PAE status to PAE[0] through

PAE[3] respectively. If less than 4 queues are used then only the associated

PAEn outputs will be required, unused PAEn outputs will be don’t care outputs.

When devices are connected in expansion mode the PAEn flag bus can also

be expanded beyond 4 bits to produce a wider PAEn bus that encompasses

all queues.

Alternatively, the 4 bit PAEn flag bus of each device can be connected together

to form a single 4 bit bus, i.e. PAE[0] of device 1 will connect to PAE[0] of device

2 etc. When connecting devices in this manner the PAEn bus can only be driven

by a single device at any time, (the PAEn outputs of all other devices must be

in high impedance state). There are two methods by which the user can select

which device has control of the bus, these are “Direct” (Addressed) mode or

“Polled” (Looped) mode, determined by the state of the FM (flag Mode) input

during a Master Reset.

PAEn BUS EXPANSION- DIRECT MODE

If FM is LOW at Master Reset then the PAEn bus operates in Direct

(addressed) mode. In direct mode the user can address the device they require

to control the PAEn bus. The address present on the 3 most significant bits of

the RDADD[5:0] address bus with ESTR (PAE flag strobe), HIGH will be

selected as the device on a rising edge of RCLK. So to address the first device

in a bank of devices the RDADD[5:0] address should be “000xx” the second

device “001xx” and so on. The 3 most significant bits of the RDADD[5:0] address

bus correspond to the device ID inputs ID[2:0]. The PAEn bus will change status

to show the new device selected 1 RCLK cycle after device selection. Note, that

if a read or write operation is occurring to a specific queue, say queue ‘x’ on

the same cycle as a PAEn bus switch to the device containing queue ‘x’, then

there may be an extra RCLK cycle delay before that queues status is correctly

shown on the respective output of the PAEn bus. However, the “active” PAE

flag will show correct status at all times.

Devices can be selected on consecutive RCLK cycles, that is the device

controlling the PAEn bus can change every RCLK cycle. Also, data can be read

out of a FIFO queue on the same RCLK rising edge that a device is being selected

on the PAEn bus, the only restriction being that a read queue selection and PAEn

bus selection cannot be made on the same cycle.

PAEn BUS EXPANSION- POLLED MODE

If FM is HIGH at Master Reset then the PAEn bus operates in Polled

(Looped) mode. In polled mode the PAEn bus automatically cycles through

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

the devices connected in expansion. In expansion mode one device will be

set as the Master, MAST input tied HIGH, all other devices will have MAST

tied LOW. The master device is the first device to take control of the PAEn bus

and place the PAE status of its queues onto the bus on the first rising edge of

RCLK after the MRS input goes HIGH once a Master Reset is complete. The

ESYNC (PAE sync pulse) output of the first device (master device), will be HIGH

for one cycle of RCLK indicating that it is has control of the PAEn bus for that

cycle.

The device also passes a “token” onto the next device in the chain, the next

device assuming control of the PAEn bus on the next RCLK cycle. This token

passing is done via the EXO outputs and EXI inputs of the devices (“PAEn

Expansion Out” and “PAEn Expansion In”). The EXO output of the first device

connecting to the EXI input of the second device in the chain, the EXO of the

second device connects to the EXI of the third device and so on. The EXO of

the final device in a chain connects to the EXI of the first device, so that once the

PAEn bus has cycled through all devices control is again passed to the first

device. The EXO output of a device will be HIGH for the RCLK cycle it has control

of the bus.

Please refer to Figure 25,

PAE

n Bus – Polled Mode for timing information.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

D17-D9

(a) x18 INPUT to x18 OUTPUT - BIG ENDIAN

(b) x18 INPUT to x18 OUTPUT - LITTLE ENDIAN

Write to FIFO

Read from FIFO

BYTE ORDER ON INPUT PORT:

BYTE ORDER ON OUTPUT PORT:

Read from FIFO

1st: Read from FIFO

2nd: Read from FIFO

(d) x18 INPUT to x9 OUTPUT - LITTLE ENDIAN

1st: Read from FIFO

2nd: Read from FIFO

(a) x9 INPUT to x18 OUTPUT - BIG ENDIAN

1st: Write to FIFO

BYTE ORDER ON INPUT PORT:

2nd: Write to FIFO

BYTE ORDER ON OUTPUT PORT:

Read from FIFO

(a) x9 INPUT to x18 OUTPUT - LITTLE ENDIAN

Read from FIFO

5941 drw07

BE IW OW

H L H

BE IW OW

L H L

BE IW OW

H H L

BE IW OW

L L H

BE IW OW

H L L

BE IW OW

L L L

D8-D0

Q17-Q9 Q8-Q0

D17-D9 D8-D0

D17-Q9 D8-Q0

Q17-Q9 Q8-Q0

Figure 3. Bus-Matching Byte Arrangement

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

MRS

WEN

REN

RSS

FSTR,

ESTR

5941 drw08

DFM

HIGH = Default Programming

LOW = Serial Programming

HIGH = Offset Value is 128

LOW = Offset value is 8

RSS

RSR

SENI

WADEN,

RADEN

RSS

OW, IW

HIGH = Looped

LOW = Strobed (Direct)

ID0, ID1,

ID2

RSS

MAST

HIGH = Master Device

LOW = Slave Device

RSS

RSF

PAF

RSF

PAE

RSF

LOGIC "1" if OE is LOW and device is Master

HIGH-Z if OE is HIGH or Device is Slave

LOGIC "1" if Master Device

HIGH-Z if Slave Device

LOGIC "1" if Master Device

HIGH-Z if Slave Device

LOGIC "0" if Master Device

HIGH-Z if Slave Device

LOGIC "0" if Master Device

LOGIC "1" if Master Device

HIGH-Z if Slave Device

PAFn

PAEn

HIGH-Z if Slave Device

LOGIC “0" if Master Device

Figure 4. Master Reset

NOTES:

1. OE can toggle during this period.

2. PRS should be HIGH during a MRS.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

Figure 6. Serial Port Connection for Serial Programming

DFM MRS

SENI SENO

MQ1

SI SO

SCLK

DFM MRS

SENI SENO

MQ2

SI SO

SCLK

DFM MRS

SENI SENO

MQn

SI SO

SCLK

Serial Enable

Serial Input

Serial Clock

Default Mode

DFM = 0

Master Reset

Serial Loading

Complete

5941 drw10

Figure 5. Partial Reset

NOTES:

1. For a Partial Reset to be performed on a Queue, that Queue must be selected on both the write and read ports.

2. The queue must be selected a minimum of 2 clock cycles before the Partial Reset takes place, on both the write and read ports.

3. The Partial Reset must be LOW for a minimum of 1 WCLK and 1 RCLK cycle.

4. Writing or Reading to the queue (or a queue change) cannot occur until a minimum of 3 clock cycles after the Partial Reset has gone HIGH, on both the write and read ports.

5. The PAF flag output for Qx on the PAFn flag bus may update one cycle later than the active PAF flag.

6. The PAE flag output for Qx on the PAEn flag bus may update one cycle later than the active PAE flag.

WCLK

RCLK

RDADD

RADEN

r-2 r-1 r

PRS

r+2

r+1

PRSH

PRSS

REN

ENS

r+3

ENS

ROV

RAE

PAE

5937 drw09

WEN

WADEN

WRADD Qx

w-2 w-1 w w+1 w+2

ENS

w+3

ENS

WFF

PAF

WAF

Active Bus

PAF-Qx

(5)

PAF

Active Bus

PAE-Qx

(6)

PAE

PRSH

PRSS

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Figure 7. Serial Programming

RCLK

WEN

SENO

(MQ1)

WADEN/

FSTR

RADEN/

ESTR

WCLK

5941 drw11

WFF

ENS

ROV

PCWQ

PCRQ

HIGH - Z

(Slave Device)

(MQ1)

MRS

SCLK

SENI

(MQ1)

RSR

SENO

1st 2nd nth 1st 2nd nth 1st 2nd nth

SENS

SENO

(MQ2)

SENO

(MQ8)

B21

SDS

SDH

SENO

SCLK

SCKL

SCKH

Programming Complete

1st Device in Chain 2nd Device in Chain Final Device in Chain

SDO

SDOP

SENOP

NOTES:

1. SENI can be toggled during serial loading. Once serial programming of a device is complete, the SENI and SI inputs become transparent. SENI → SENO and SI → SO.

2. DFM is LOW during Master Reset to provide Serial programming mode, DF is don't care.

3. When SENO of the final device is LOW no further serial loads will be accepted.

4. n = 19+(Qx72); where Q is the number of queues required for the IDT72V51233/72V51243/72V51253.

5. This diagram illustrates 8 devices in expansion.

6. Programming of all devices must be complete (SENO of the final device is LOW), before any write or read port operations can take place, this includes queue selections.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

DFM MRS

SENI SENO

MQ1

WCLK

Serial Enable

(can be tied LOW)

WCLK

Default Mode

DFM = 1

Master Reset

Serial Loading

Complete

DFM MRS

SENI SENO

MQ2

WCLK

DFM MRS

SENI SENO

MQn

WCLK

RCLK

WEN

WADEN/

FSTR

RADEN/

ESTR

5941 drw11a

tWFF

tENS

tROV

tPCWQ

tQS tQH

tPCRQ

HIGH - Z

(Slave Device)

SENO

(MQ1)

tSENO

SENO

(MQ2)

SENO

(MQ8)

tSENO

WCLK

MRS

1st Device in Chain

1st 2nd nth

3rd

2nd Device in Chain

1st 2nd nth

Final Device in Chain

1st 2nd nth

Programming

Complete

tSENO

Serial Port Connection for Default Programming

SI SO XSI SOXSI SOX

Figure 8. Default Programming

NOTES:

1. This diagram illustrates multiple devices connected in expansion.

The SENO of the final device in a chain is the "programming complete" signal.

2. SENI of the first device in the chain can be held LOW

3. The SENO of a device should connect to the SENI of the next device in the chain.

The final device SENO is used to indicate programming complete.

4. When Default Programming is complete the SENO of the final device will go LOW.

5. SCLK is not used and can be tied LOW.

6. Programming of all devices must be complete (SENO of the final device is LOW),

before any write or read port operations can take place, this includes queue selections.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Figure 9. Write Queue Select, Write Operation and Full Flag Operation

WCLK

WADEN

WRADD Q

WFF

5941 drw12

WEN

ENS

D-2

D-1

Din

WFF

Previous Q Status

No Writes

FIFO Queue Full

*A* *B* *C* *D* *E* *F* *G*

ENH

WFF

RCLK

SKEW1

REN

ENS

RDADD Q

RADEN

Qout

Previous Q, Word, W Previous Q, W+1

PFT

Qy, W0

PFT

Qy, W1Qy, W2

*H* *I* *J*

*AA* *BB* *CC* *DD* *EE* *FF*

NOTE:

OE is active LOW.

Cycle:

*A* Queue, Qx is selected on the write port.

The FF flag is providing status of a previously selected queue, within the same device.

*AA* Queue, Qy is selected for read operations.

*B* The FF flag output updates to show the status of Qx, it is not full.

*BB* Word W+1 is read from the previous queue regardless of REN due to FWFT.

*C* Word, Wd is written into Qx. This causes Qx to go full.

*CC* Word, W0 is read from Qy regardless of REN, this is due to the FWFT effect.

*D* Queue, Qy is selected within the same device as Qx. A write to Qx cannot occur on this cycle because it is full, FF is LOW.

*DD* No reads occur, REN is HIGH.

*E* Again, a write to Qx cannot occur on this cycle because it is full, FF is LOW. The FF flag updates after time tWFF to show that queue, Qy is not full.

*EE* Word, W1 is read from Qy, this causes Qy to go “not full”, FF flag goes HIGH after time, tSKEW1 + tWFF. Note, if tSKEW1 is violated the time FF HIGH will be: tSKEW1 + WCLK + tWFF.

*F* Word, Wd-2 is written into Qy.

*FF* Word, W2 is read from Qy.

*G* Word, Wd-1 is written into Qy.

*H* Word, Wd is written into Qy, this causes Qy to go full, FF goes LOW.

*I* No writes occur to Qy.

*J* Qy goes “not full” based on reading word W1 from Qy on cycle *EE*.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

5941 drw12a

W1 W2 W3

WCLK

ENH

WEN

RCLK

SKEW1

ENS

REN

W1 Qy

FWFT

W2 Qy

FWFT

W3 QyLast Word Read Out of Queue

Qout

ROV

ENS

Figure 10. Write Operations & First Word Fall Through

NOTES:

1. Qy has previously been selected on both the write and read ports.

2. OE is LOW.

3. The First Word Latency = tSKEW1 + RCLK + tA. If tSKEW1 is violated an additional RCLK cycle must be added.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

WCLK

WADEN

WRADD

(Device 1)

FFLZ

5941 drw13

WEN

ENS

1 Q3

Din

WFF

HIGH-Z

RCLK

ENH

ENS

ENH

Addr=00111

WFF

1 Q0

FFHZ

WFF

HIGH-Z

(Device 2)

FFHZ

HIGH-Z

FFLZ

SKEW1

Addr=00100

RDADD

RADEN

*A* *B* *C* *D* *E* *F* *G* *H* *I*

No Write

*J*

Qout

Previous Q W

X-1

Previous Q W

PFT

-Q

Word W

PFT

*AA* *BB* *CC*

Addr=01010

Addr=001000

Figure 11. Full Flag Timing in Expansion Mode

NOTE:

1. REN = HIGH.

Cycle:

*A* Queue, Q3 of device 1 is selected on the write port.

The FF flag of device 1 is in High-Impedance, the write port of device 2 was previously selected.

WEN is HIGH so no write occurs.

*AA* Queue, Q0 of device 1 is selected on the read port.

*B* The FF flag of device 2 goes to High-Impedance and the FF flag of device 1 goes to Low-Impedance, logic HIGH indicating that D1 Q3 is not full.

WEN is HIGH so no write occurs.

*BB* Word, Wx is read from the previously selected queue, (due to FWFT).

*C* Word, Wd is written into Q3 of D1. This write operation causes Q3 to go full, FF goes LOW.

*CC* The first word from Q0 of D1 selected on cycle *AA* is read out, this occurred regardless of REN due to FWFT. This read caused Q0 to go not full, therefore the FF flag will go HIGH after: tSKEW1 + tWFF.

Note if tSKEW1 is violated the time to FF flag HIGH is tSKEW1 + WLCK + tWFF.

*D* Queue, Q0 of device 1 is selected on the write port. No write occurs on this cycle.

*E* The FF flag updates to show the status of D1 Q0, it is not full, FF goes HIGH.

*F* Word, Wd is written into Q0 of D1. This causes the queue to go full, FF goes LOW.

*G* No write occurs regardless of WEN, the FF flag is LOW preventing writes.

*H* The FF flag goes HIGH due to the read from Q0 of D1 on cycle *CC*. (This read is not an enabled read, it is due to the FWFT operation).

*I* Queue, Q2 of device 2 is selected on the write port.

*J* The FF flag of device 1 goes to High-Impedance, this device was deselected on the write port on cycle *I*. The FF flag of device 2 goes to Low-Impedance and provides status of Q2 of D2.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

Figure 12. Read Queue Select, Read Operation

RCLK

5941 drw14

RDADD

RADEN

REN

ENS

ENH

ENS

OUT

Wn-3

Wn-2

Previous Q, Q

Wn-1

PFT

W1Q

ROV

Previous Q

*A* *B* *C* *D* *E* *F* *G* *H*

PFT

*I*

Cycle:

*A* Word Wn-2 is read from a previously selected queue Qp on the read port.

*B* Wn-1 is read.

*C* Reads are disabled, Wn-1 remains on the output bus.

*D* A new queue, QF is selected for read operations.

*E* Due to the First Word Fall Through effect, a final read from the previous queue, Qp will take place, Wn from Qp is placed onto the output bus regardless of REN.

*F* The next word available in the new queue, QF-W0 falls through to the output bus, again this is regardless of REN.

*G* A new queue, QG is selected for read operations. (This queue is an empty queue). Word, W1 is also read from QF.

*H* Word, W2 is read from QF. This occurs regardless of REN due to FWFT.

*I* Word W2 from QF remains on the output bus because QG is empty. The Output Valid Flag, OV goes HIGH to indicate that the current word is not valid, i.e. QG is empty.

W2 is the last word in QG.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Figure 13. Output Valid Flag Timing (In Expansion Mode)

RCLK

RADEN

tQHtQS

tAHtAS

RDADD D

(Device 1)

5941 drw15

tENS

REN

tAHtAS

tQH

tQS

Qout

(Device 1)

tROV

HIGH-Z

WCLK

(Device 2)

tOVHZ

tSKEW1

tAH

tAS

WRADD D

tQHtQS

WADEN

tDH

tDS

Din

Q3 WD Last Word

tOLZ

PFT W

e-1

Last Word

tOVLZ tROV tROV tROV

WEN

tENS tENH

*A* *B* *C* *D* *E* *F* *G* *H* *I*

Addr=001011 Addr=001010

Cycle:

*A* Queue 3 of Device 1 is selected for read operations. The OV is currently being driven by Device 2, a queue within device 2 is selected for reads. Device 2 also has control

of Qout bus, its Qout outputs are in Low-Impedance. This diagram only shows the Qout outputs of device 1. (Reads are disabled).

*B* Reads are now enabled. A word from the previously selected queue of Device 2 will be read out.

*C* The Qout of Device 1 goes to Low-Impedance and word Wd is read from Q3 of D1. This happens to be the last word of Q3. Device 2 places its Qout outputs into

High-Impedance, device 1 has control of the Qout bus. The OV flag of Device 2 goes to High-Impedance and Device 1 takes control of OV. The OV flag of Device 1 goes LOW

to show that Wd of Q3 is valid.

*D* Queue 2 of device 1 is selected for read operations. The last word of Q3 was read on the previous cycle, therefore OV goes HIGH to indicate that the data on the Qout is

not valid (Q3 was read to empty). Word, Wd remains on the output bus.

*E* The last word of Q3 remains on the Qout bus, OV is HIGH, indicating that this word has been previously read.

*F* The next word (We-1), available from the newly selected queue, Q2 of device 1 is now read out. This will occur regardless of REN, 2 RCLK cycles after queue selection

due to the FWFT operation. The OV flag now goes LOW to indicate that this word is valid.

*G* The last word, We is read from Q2, this queue is now empty.

*H* The OV flag goes HIGH to indicate that Q2 was read to empty on the previous cycle.

*I* Due to a write operation the OV flag goes LOW and data word W0 is read from Q2. The latency is: tSKEW1 + 1*RCLK + tROV.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

Figure 14. Read Queue Selection with Reads Disabled

Figure 15. Read Queue Select, Read Operation and

Timing

RCLK

5941 drw16

RDADD

RADEN

REN

ENS

OUT QP

WD+1

WD+2

WX+1

ENS

ENH

WD+3 QP

WD+4

*A* *B* *C* *D* *E* *F* *G* *H* *I* *J*

ENH

RCLK

RADEN

RDADD Q

5941 drw17

Qout

ROV

OLZ

PFT

ENS

REN

Previous Data in O/P Register

No Read

QB is Empty

ROV

*B* *C* *E* *F**D**A* *H* *I**G*

ENH

ENS

OHZ

Cycle:

*A* Word Wd+1 is read from the previously selected queue, Qp.

*B* Reads are disabled, word Wd+1 remains on the output bus.

*C* A new queue, Qn is selected for read port operations.

*D* Due to FWFT operation Word, Wd+2 of Qp is read out regardless of REN.

*E* The next available word Wx of Qn is read out regardless of REN, 2 RCLK cycles after queue selection. This is FWFT operation.

*F* The queue, Qp is again selected.

*G* Word Wx+1 is read from Qn regardless of REN, this is due to FWFT.

*H* Word Wd+3 is read from Qp, this read occurs regardless of REN due to FWFT operation.

*I* Word Wd+4 is read from Qp.

*J* Reads are disabled on this cycle, therefore no further reads occur.

NOTES:

1. The Output Valid flag, OV is HIGH therefore the previously selected queue has been read to empty. The Output Enable input is Asynchronous, therefore the Qout output bus

will go to Low-Impedance after time tOLZ.

The data currently on the output register will be available on the output after time tOE. This data is the previous data on the output register, this is the last word read out of the

previous queue.

2. In expansion mode the OE inputs of all devices should be connected together. This allows the output busses of all devices to be High-Impedance controlled.

Cycle:

*A* Queue A is selected for reads. No data will fall through on this cycle, the previous queue was read to empty.

*B* No data will fall through on this cycle, the previous queue was read to empty.

*C* Word, W0 from Qa is read out regardless of REN due to FWFT operation. The OV flag goes LOW indicating that Word W0 is valid.

*D* Reads are disabled therefore word, W0 of Qa remains on the output bus.

*E* Reads are again enabled so word W1 is read from Qa.

*F* Word W2 is read from Qa.

*G* Queue, Qb is selected on the read port. This queue is actually empty. Word, W3 is read from Qa.

*H* Word, W4 falls through from Qa.

*I* Output Valid flag, OV goes HIGH to indicate that Qb is empty. Data on the output port is no longer valid.

Output Enable is taken HIGH, this is Asynchronous so the output bus goes to High-Impedance after time, tOHZ.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

RCLK

RADEN

Qout

REN

0001xx

RDADD

NULL QUEUE

SELECT

*A* *B* *C* *E* *F*

ENS

Q1 Wn-3 Q1 Wn-2 Q1 Wn-1

Q1 Wn

Q3 W0

FWFT

ROV

5941 drw18

SELECT

NEW QUEUE

*D*

000011

ENH

Figure 16. Read Operation and Null Queue Select

NOTES:

1 . The purpose of the Null queue operation is so that the user can stop reading a block (packet) of data from a queue without filling the 2 stage output pipeline with the next words

from that queue.

2. Please see Figure 17, Null Queue Flow Diagram.

Cycle:

*A* Null Q of device 0 is selected, when word Wn-1 from previously selected Q1 is read.

*B* REN is HIGH and Wn (Last Word of the Packet) of Q1 is pipelined onto the O/P register.

Note: *B* and *C* are a minimum 2 RCLK cycles between Q selects.

*C* The Null Q is seen as an empty FIFO on the read side, therefore Wn of Q1 remains in the O/P register and OV goes HIGH.

*D* A new Q, Q3 is selected and the 1st word of Q3 will fall through present on the O/P register on cycle *F*.

5941 drw19

Queue 1

Memory

*A*

Null

Queue

*B*

Null

Queue

*C*

O/P Reg.

*D* *E* *F*

Null

Queue

Queue 3

Memory

Queue 3

Memory

O/P Reg. O/P Reg. O/P Reg. O/P Reg. O/P Reg.

Wn-1

Figure 17. Null Queue Flow Diagram

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

WCLK

WADEN

tQHtQS

tAHtAS

WRADD

D1 Q2

PAF

(Device 1)

tAFLZ

5941 drw20

WEN

tENS

tAHtAS

tQH

tQS

tDH

tDS

WD-m

Din

tWAF tWAF

HIGH-Z

tENH

D1 Q0

PAF

(Device 2)

tFFHZ

D1 Q2

*B* *C* *E* *F*

*D*

*A*

Figure 18. Almost Full Flag Timing and Queue Switch

Figure 19. Almost Full Flag Timing

WCLK

WEN

PAF

RCLK

WAF

REN

5941 drw21

D - (m+1) words in FIFO

(2)

D - m words in FIFO

121

D-(m+1) words

in FIFO

tWAF

tENHtENS

tSKEW2

tENHtENS

tCLKL

Cycle:

*A* Queue 2 of Device 1 is selected on the write port. A queue within Device 2 had previously been selected. The PAF output of device 1 is High-Impedance.

*B* No write occurs.

*C* Word, Wd-m is written into Q2 causing the PAF flag to go from HIGH to LOW. The flag latency is 2 WCLK cycles + tWAF.

*D* Queue 0 if device 1 is now selected for write operations. This queue is not almost full, therefore the PAF flag will update after a 2 WCLK + tWAF latency.

*E* The PAF flag goes LOW based on the write 2 cycles earlier.

*F* The PAF flag goes HIGH due to the queue switch to Q0.

NOTE:

1. The waveform here shows the PAF flag operation when no queue switches are occurring and a queue selected on both the write and read ports is being written to then read

from at the almost full boundary.

Flag Latencies:

Assertion: 2*WCLK + tWAF

De-assertion: tSKEW2 + WCLK + tWAF

If tSKEW2 is violated there will be one extra WCLK cycle.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Figure 20. Almost Empty Flag Timing and Queue Switch

Figure 21. Almost Empty Flag Timing

RCLK

RADEN

RDADD

D1 Q3

PAE

(Device 1)

AELZ

5941 drw22

REN

OLZ

Qout

RAE

HIGH-Z

D1 Q1

PAE

(Device 2)

AEHZ

HIGH

HIGH-Z

D1 Q3 Wn

HIGH-Z

*B* *C* *E* *F**D**A*

D1 Q3 Wn+1

D1 Q1 W0

D1 Q1 W1

*G*

WCLK

ENH

CLKH

CLKL

WEN

PAE

RCLK

ENS

n+1 words in FIFO

RAE

SKEW2

RAE

REN

5941 drw23

ENS

ENH

n+2 words in FIFO n+1 words in FIFO

Cycle:

*A* Queue 3 of Device 1 is selected on the read port. A queue within Device 2 had previously been selected. The PAE flag output and the data outputs of device 1 are High-Impedance.

*B* No read occurs.

*C* The PAE flag output now switches to device 1. Word, Wn is read from Q3 due to the FWFT operation. This read operation from Q3 is at the almost empty boundary, therefore

PAE will go LOW 2 RCLK cycles later.

*D* Q1 of device 1 is selected.

*E* The PAE flag goes LOW due to the read from Q3 2 RCLK cycles earlier. Word Wn+1 is read out due to the FWFT operation.

*F* Word, W0 is read from Q1 due to the FWFT operation. The PAE flag goes HIGH to show that Q1 is not almost empty.

NOTE:

1. The waveform here shows the PAE flag operation when no queue switches are occurring and a queue selected on both the write and read ports is being written to then read

from at the almost empty boundary.

Flag Latencies:

Assertion: 2*RCLK + tRAE

De-assertion: tSKEW2 + RCLK + tRAE

If tSKEW2 is violated there will be one extra RCLK cycle.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

WCLK

Prev PAEn

RCLK

ESTR

RDADD

Device 5

101 xxx100 011

D5Q3

SKEW3

Previous value loaded on to PAE bus

1xxx

Device 5

RADEN

STH

STS

PAE

5941 drw24

Device 5 PAE

RAE

*AA* *BB* *CC* *DD* *FF**EE*

RAE

D5 Qx Status

Bus PAEnPrevious value loaded on to PAE bus

Device 5

PAEHZ

PAEZL

1xxx

REN

ENH

ENS

Device 5 -Qn Wy

D5 Q3

Wy+1

D5 Q3

Wy+3

D5 Q3

Wy+2

D5 Q3

Wa+1

D5 Qn

D5 Qx

WEN

WADEN

FSTR

100 11

WRADD D5Q3 D3Q2

D5 Q3

Wn+1

D5Q3

D3 Q2

01110

Device 4

100 xx

*A* *B* *C* *D* *E* *F*

ENS

ENH

STH

STS

Device 5 PAEn

ENS

ENH

Wp+1

Writes to Previous Q

RAE

D5 Q3

status

1xxx

Device 5

1xxx

Figure 22.

PAE

n - Direct Mode, Flag Operation – Devices in Expansion

Cycle:

*A* Queue 3 of Device 5 is selected for write operations.

Word, Wp is written into the previously selected queue.

*AA* Queue 3 of Device 5 is selected for read operations.

Another device has control of the PAEn bus.

The discrete PAE output of device 5 is currently in High-Impedance and the PAE active flag is controlled by the previously selected device.

*B* Word Wp+1 is written into the previously selected queue.

*BB* Word, Wa+1 is read from Qx of D5, due to FWFT operation.

*C* Word, Wn is written into the newly selected queue, Q3 of D5. This write will cause the PAE flag on the read port to go from LOW to HIGH (not almost empty) after time,

tSKEW3 + RCLK + tRAE (if tSKEW3 is violated one extra RCLK cycle will be added.

*CC* Word, Wy from the newly selected queue, Q3 will be read out due to FWFT operation.

Device 5 is selected on the PAEn bus. Q3 of device 5 will therefore have is PAE status output on PAE[3]. There is a single RCLK cycle latency before the PAEn bus changes

to the new selection.

*D* Queue 2 of Device 3 is selected for write operations.

Word Wn+1 is written into Q3 of D5.

*DD* The PAEn bus changes control to D5, the PAEn outputs of D5 go to Low-Impedance and are placed onto the outputs. The previously selected device now places its

PAEn outputs into High-Impedance to prevent bus contention. Word, Wy+1 is read from Q3 of D5.

The discrete PAE flag will go HIGH to show that Q3 of D5 is not almost empty. Q3 of device 5 will have its PAE status output on PAE[3].

*E* No writes occur.

*EE* Word, Wy+2 is read from Q3 of D5.

*F* Device 4 is selected on the write port for the PAFn bus.

Word, Wx is written into Q2 of D3.

*FF* The PAEn bus updates to show that Q3 of D5 is almost empty based on the reading out of word, Wy+1.

The discrete PAE flag goes LOW to show that Q3 of D5 is almost empty based on the reading of Wy+1.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

RCLK

OLZ

REN

RADEN

ESTR

WRADD

000 001

RDADD D0Q1

D0 Q1

111 xxx

Device 7

110 010

*A* *B* *C* *D* *E* *F*

000 xxx

STH

STS

STH

STS

5941 drw25

*AA*

xx0x

Device 0

Device 0 PAFn

Bus PAFn

*BB* *CC* *DD* *EE* *FF*

PAFLZ

xx1x

Device 0 Device 0

PAF

xx0x

Device 0 xx1x

Device 0 Device 0 xx0xPrevious Device

Prev. PAFnPrevious Device

PAFHZ

HIGH-Z

Device 0 PAF HIGH - Z

PAFLZ

WAF

Qout

D6Q2

Prev. Q

D-M+1

FSTR

WCLK

SKEW3

X +1

Prev. Q

D0 Q1

WEN

ENS

WADEN

D - M + 2

*G*

D0 Q1

D6 Q2

ENH

Din

Word W

D0 Q1

y+1

D0 Q1

y+2

D0 Q1

Device 0

Figure 23.

PAF

n - Direct Mode, Flag Operation – Devices in Expansion

Cycle:

*A* Queue 1 of device 0 is selected for read operations.

The last word in the output register is available on Qout. OE was previously taken LOW so the output bus is in Low-Impedance.

*AA* Device 0 is selected for the PAFn bus. The bus is currently providing status of a previously selected device X.

*B* Word, Wx+1 is read out from the previous queue due to the FWFT effect.

*BB* Queue 1 of device 0 is selected on the write port.

The PAFn bus is updated with the device selected on the previous cycle, device 0 PAF[1] is LOW showing the status of queue 1.

The PAFn outputs of the device previously selected on the PAFn bus go to High-Impedance.

*C* Device 7 is selected for the PAFn bus.

Word, Wd-m+1 is read from Q1 D0 due to the FWFT operation. This read is at the PAFn boundary of queue D0 Q1. This read will cause the PAF[1] output to go from

LOW to HIGH (almost full to not almost full), after a delay tSKEW3 + WCLK + tPAF. If tSKEW3 is violated add an extra WCLK cycle.

*CC* PAFn continues to show status of D0.

*D* No read operations occur, REN is HIGH.

*DD* PAF[1] goes HIGH to show that D0 Q1 is not almost empty due to the read on cycle *C*.

The active queue PAF flag of device 0 goes from High-Impedance to Low-Impedance.

Word, Wy is written into D0 Q1.

*E* Queue 2 of Device 6 is selected for write operations.

*EE* Word, Wy+1 is written into D0 Q1.

*F* Word, Wd-m+2 is read out due to FWFT operation.

*FF* PAF[1] and the discrete PAF flag go LOW to show the write on cycle *DD* causes Q1 of D0 to again go almost full.

Word, Wy+2 is written into D0 Q1.

*G* Word, W0 is read from Q0 of D6, selected on cycle *E*, due to FWFT.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

WCLK

5941 drw26

FSYNC

FSYNC0

(MASTER)

FXO0 /

FXI1

FXO

FSYNC

FSYNC1

(SLAVE)

FXO1 /

FXI2

FXO

FSYNC

FSYNC2

(SLAVE)

FXO2 /

FXI0

FXO

PAF[3:0]

PAF

Device 0 Device 1 Device 2 Device 0

FSYNC

FXO

Figure 24.

PAF

n Bus - Polled Mode

NOTE:

1. This diagram is based on 3 devices connected to expansion mode.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

RCLK

5941 drw27

ESYNC

ESYNC0

EXO0 /

EXI1

EXO

ESYNC

ESYNC1

EXO1 /

FXI2

EXO

ESYNC

ESYNC2

EXO2 /

EXI0

EXO

PAEn

PAE

Device 0 Device 1 Device 2 Device 0

ESYNC

EXO

Figure 25.

PAE

n Bus - Polled Mode

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

WRADD

WADEN

WCLK

WEN

FSTR

PAFn

FSYNC

PAF

SCLK

RCLK

REN

ESTR

PAEn

ESYNC

PAE

RDADD

RADEN

SO FXO EXO

SI FXI EXI

WRADD

WADEN

WCLK

WEN

FSTR

PAFn

FSYNC

PAF

SCLK

RCLK

REN

ESTR

PAEn

ESYNC

PAE

RDADD

RADEN

SO FXO EXO

SI FXI EXI

WRADD

WADEN

WCLK

WEN

FSTR

PAFn

FSYNC

PAF

SCLK

RCLK

REN

ESTR

PAEn

ESYNC

PAE

RDADD

RADEN

SENO FXO EXO

Q0-Q17

SI FXI EXI

Data Bus

Write Clock

Write Enable

Write Queue Select

Full Strobe

Programmable Almost Full

Write Address

Full Sync1

Full Flag

Almost Full Flag

Serial Clock

Output Data Bus

Read Clock

Read Enable

Read Queue Select

Empty Strobe

Programmable Almost Empty

Read Address

Empty Sync 1

Output Valid Flag

Almost Empty Flag

Serial Programming Data Input

DEVICE

Full Sync2 Empty Sync 2

Full Sync n Empty Sync n

SENO

SENI

SENO

SENI

DONE

5941 drw28

D0-D17

Q0-Q17

D0-D17

D0-D17 Q0-Q17

SENI

Serial Enable

Figure 26. Multi-Queue Expansion Diagram

NOTES:

1 . If devices are configured for Direct operation of the PAFn/PAEn flag busses the FXI/EXI of the MASTER device should be tied LOW. All other devices tied HIGH. The FXO/EXO

outputs are DNC (Do Not Connect).

2. Q outputs must not be mixed between devices, i.e. Q0 of device 1 must connect to Q0 of device 2, etc.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

TAP

Cont-

roller

Mux

DeviceID Reg.

Boundary Scan Reg.

Bypass Reg.

clkDR, ShiftDR

UpdateDR

TDO

TDI

TMS

TCLK

TRST

clklR, ShiftlR

UpdatelR

Instruction Register

Instruction Decode

Control Signals 5941 drw29

JTAG INTERFACE

Five additional pins (TDI, TDO, TMS, TCK and TRST) are provided to

support the JTAG boundary scan interface. The IDT72V51233/72V51243/

72V51253 incorporates the necessary tap controller and modified pad cells to

implement the JTAG facility.

Note that IDT provides appropriate Boundary Scan Description Language

program files for these devices.

The Standard JTAG interface consists of four basic elements:

••

•Test Access Port (TAP)

••

•TAP controller

••

•Instruction Register (IR)

••

•Data Register Port (DR)

The following sections provide a brief description of each element. For a

complete description refer to the IEEE Standard Test Access Port Specification

(IEEE Std. 1149.1-1990).

The Figure below shows the standard Boundary-Scan Architecture

Figure 27. Boundary Scan Architecture

TEST ACCESS PORT (TAP)

The Tap interface is a general-purpose port that provides access to the

internal of the processor. It consists of four input ports (TCLK, TMS, TDI, TRST)

and one output port (TDO).

THE TAP CONTROLLER

The Tap controller is a synchronous finite state machine that responds to

TMS and TCLK signals to generate clock and control signals to the Instruction

and Data Registers for capture and update of data.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

Test-Logic

Reset

Run-Test/

Idle

Select-

DR-Scan

Select-

IR-Scan

111

Capture-IR

Capture-DR

EXit1-DR

Pause-DR

Exit2-DR

Update-DR

Exit1-IR

Exit2-IR

Update-IR

5941 drw30

Shift-DR

Shift-IR

Pause-IR

Input = TMS

Refer to the IEEE Standard Test Access Port Specification (IEEE Std.

1149.1) for the full state diagram

All state transitions within the TAP controller occur at the rising edge of the

TCLK pulse. The TMS signal level (0 or 1) determines the state progression

that occurs on each TCLK rising edge.

CAPTURE-DR

Data is loaded from the parallel input pins or core outputs into the Data

SHIFT-DR

The previously captured data is shifted in serially, LSB first at the rising edge

of TCLK in the TDI/TDO path and shifted out serially, LSB first at the falling edge

of TCLK towards the output.

UPDATE-DR

The shifting process has been completed. The data is latched into their

parallel outputs in this state to be accessed through the internal bus.

Figure 28. TAP Controller State Diagram

EXIT1-DR / EXIT2-DR

This is a temporary controller state. If TMS is held high, a rising edge applied

to TCK while in this state causes the controller to enter the Update-DR state. This

terminates the scanning process. All test data registers selected by the current

instruction retain their previous state unchanged.

PAUSE-DR

This controller state allows shifting of the test data register in the serial path

between TDI and TDO to be temporarily halted. All test data registers selected

by the current instruction retain their previous state unchanged.

Capture-IR, Shift-IR and Update-IR, Exit-IR and Pause-IR are

similar to Data registers. These instructions operate on the instruction registers.

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

THE INSTRUCTION REGISTER

The Instruction register allows an instruction to be shifted in serially into the

processor at the rising edge of TCLK.

The Instruction is used to select the test to be performed, or the test data

at the completion of the shifting process when the TAP controller is at Update-

IR state.

The instruction register must contain 4 bit instruction register-based cells

which can hold instruction data. These mandatory cells are located nearest the

serial outputs they are the least significant bits.

TEST DATA REGISTER

The Test Data register contains three test data registers: the Bypass, the

Boundary Scan register and Device ID register.

These registers are connected in parallel between a common serial input

and a common serial data output.

The following sections provide a brief description of each element. For a

complete description, refer to the IEEE Standard Test Access Port Specification

(IEEE Std. 1149.1-1990).

TEST BYPASS REGISTER

The register is used to allow test data to flow through the device from TDI

to TDO. It contains a single stage shift register for a minimum length in serial path.

When the bypass register is selected by an instruction, the shift register stage

is set to a logic zero on the rising edge of TCLK when the TAP controller is in

the Capture-DR state.

The operation of the bypass register should not have any effect on the

operation of the device in response to the BYPASS instruction.

THE BOUNDARY-SCAN REGISTER

The Boundary Scan Register allows serial data TDI be loaded in to or read

out of the processor input/output ports. The Boundary Scan Register is a part

of the IEEE 1149.1-1990 Standard JTAG Implementation.

THE DEVICE IDENTIFICATION REGISTER

The Device Identification Register is a Read Only 32-bit register used to

specify the manufacturer, part number and version of the processor to be

determined through the TAP in response to the IDCODE instruction.

IDT JEDEC ID number is 0xB3. This translates to 0x33 when the parity

is dropped in the 11-bit Manufacturer ID field.

For the IDT72V51233/72V51243/72V51253, the Part Number field con-

tains the following values:

Device Part# Field (HEX)

IDT72V51233 0x411

IDT72V51243 0x412

IDT72V51253 0x413

JTAG INSTRUCTION REGISTER

The Instruction register allows instruction to be serially input into the device

when the TAP controller is in the Shift-IR state. The instruction is decoded to

perform the following:

••

•Select test data registers that may operate while the instruction is

current. The other test data registers should not interfere with chip

operation and the selected data register.

••

•Define the serial test data register path that is used to shift data between

TDI and TDO during data register scanning.

The Instruction Register is a 4 bit field (i.e. IR3, IR2, IR1, IR0) to decode

16 different possible instructions. Instructions are decoded as follows.

JTAG INSTRUCTION REGISTER DECODING

Hex Instruction Function

Value

00 EXTEST Select Boundary Scan Register

01 SAMPLE/PRELOAD Select Boundary Scan Register

02 IDCODE Select Chip Identification data register

04 High-Impedance JTAG

0F BYPASS Select Bypass Register

The following sections provide a brief description of each instruction. For

a complete description refer to the IEEE Standard Test Access Port Specification

(IEEE Std. 1149.1-1990).

EXTEST

The mandatory EXTEST instruction is provided for external circuity and

board level interconnection check.

IDCODE

This instruction is provided to select Device Identification Register to read

out manufacture’s identity, part number and version number.

SAMPLE/PRELOAD

The mandatory SAMPLE/PRELOAD instruction allows data values to be

loaded onto the latched parallel outputs of the boundary-scan shift register prior

to selection of the boundary-scan test instruction. The SAMPLE instruction

allows a snapshot of data flowing from the system pins to the on-chip logic or

vice versa.

HIGH-IMPEDANCE

This instruction places all the output pins on the device into a High-

Impedance state.

BYPASS

The Bypass instruction contains a single shift-register stage and is set to

provide a minimum-length serial path between the TDI and the TDO pins of the

device when no test operation of the device is required.

JTAG DEVICE IDENTIFICATION REGISTER

31(MSB) 28 27 12 11 1 0(LSB)

V ersion (4 bits) Part Number (16-bit) Manufacturer ID (1 1-bit)

0X0 0X33 1

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51233/72V51243/72V51253 3.3V, MULTI-QUEUE FIFO (4 QUEUES)

18 BIT WIDE CONFIGURATION 589,824, 1,179,648 and 2,359,296 bits

tTCK

tDS tDH

TDO

TDI/

TMS

TCK

TRST

tDO

Notes to diagram:

t1 =

TCKLOW

t2 =

TCKHIGH

t3 =

TCKFALL

t4 = t

TCKRise

t5 =

tRST

(reset pulse width)

t6 = tRSR (reset recovery)

5941 drw31

Figure 29. Standard JTAG Timing

Parameter Symbol Test

Conditions Min. Max. Units

JTAG Clock Input Period tTCK - 100 - ns

JTAG Clock HIGH tTCKHIGH -40-ns

JTAG Clock Low tTCKLOW -40-ns

JTAG Clock Rise Time tTCKRise --5

(1) ns

JTAG Clock Fall Time tTCKFall --5

(1) ns

JTAG Reset tRST -50-ns

JTAG Reset Recovery tRSR -50-ns

JTAG

AC ELECTRICAL CHARACTERISTICS

(vcc = 3.3V ± 5%; Tcase = 0°C to +85°C)

NOTE:

1. 50pf loading on external output signals. NOTE:

1. Guaranteed by design.

SYSTEM INTERFACE PARAMETERS

IDT72V51233

IDT72V51243

IDT72V51253

Parameter Symbol Test Conditions Min. Max. Units

Data Output tDO = Max - 20 ns

Data Output Hold tDOH(1) 0-ns

Data Input tDS trise=3ns 10 - ns

tDH tfall=3ns 10 -

CORPORATE HEADQUARTERS for SALES: for Tech Support:

2975 Stender Way 800-345-7015 or 408-727-6116 408-330-1753

Santa Clara, CA 95054 fax: 408-492-8674 email : FIFO help @idt .com

www.idt.com

Plastic Ball Grid Array (PBGA, BB256-1)

Commercial (0°C to +70°C)

Industrial (-40°C to +85°C)

Low Power

5941 drw32

Commercial Only

Com’l & Ind’l

IDT XXXXX

Device Type

Power

Speed

Package

Process /

Temperature

Range

BLANK

(1)

72V51233 589,824 bits  3.3V Multi-Queue FIFO

72V51243 1,179,648 bits  3.3V Multi-Queue FIFO

72V51253 2,359,296 bits  3.3V Multi-Queue FIFO

Clock Cycle Time (t

CLK

)

Speed in Nanoseconds

7-5

ORDERING INFORMATION

NOTE:

1. Industrial temperature range product for the 7-5ns is available as a standard device. All other speed grades are available by special order.

DATASHEET DOCUMENT HISTORY

10/10/2001 pgs. 1, 7, 9, 13, 14, 15 and 26.

11/16/2001 pgs. 1, 4, 9, 14, 16, 17, 22, 23, 26-29 and 31.

12/19/2001 pgs. 11 and 27.

01/15/2002 pg. 46.

04/05/2002 pgs. 6, 8, 10, 12 and 47.

07/01/2002 pgs. 2, 6-11 and 27.