IDT72V51446L7-5BBI - Integrated Device Technology

JULY 2002

3.3V MULTI-QUEUE FIFO (16 QUEUES)

36 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

IDT72V51436

IDT72V51446

IDT72V51456

FEATURES:

••

•Choose from among the following memory density options:

IDT72V51436 



Total Available Memory = 589,824 bits

IDT72V51446 



Total Available Memory = 1,179,648 bits

IDT72V51456 



Total Available Memory = 2,359,296 bits

••

•Configurable from 1 to 16 Queues

••

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

Total Available Memory in blocks of 256 x 36

••

•Independent Read and Write access per queue

••

•User programmable via serial port

••

•Default Multi-Queue device configurations

– IDT72V51436 : 1,024 x 36 x 16Q

– IDT72V51446 : 2,048 x 36 x 16Q

– IDT72V51456 : 4,096 x 36 x 16Q

••

•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, PR)

••

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

••

•Shows PAE and PAF status of 8 Queues

••

•Direct or polled operation of flag status bus

••

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

and Output Bus Width)

••

•User Selectable Bus Matching Options:

– x36in to x36out

– x18in to x36out

– x9in to x36out

– x36in to x18out

– x36in to x9out

••

•FWFT mode of operation on read port

••

•Packet Ready mode of operation

••

•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

Q15

MULTI-QUEUE FIFO

FSTR

WEN

PAF

WRADD

WADEN

WCLK

PAFn

x36

DATA IN

ESTR

REN

PAE

RDADD

RADEN

RCLK

PAEn/PRn

x36

DATA OUT

WRITE CONTROL

Din Qout

READ CONTROL

WRITE FLAGS

READ FLAGS

5935 drw01

DATA PATH FLOW DIAGRAM

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

DESCRIPTION:

The IDT72V51436/72V51446/72V51456 Multi-Queue FIFO device is a

single chip within which anywhere between 1 and 16 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 8 bit programmable flag busses are available, providing status of queues

not selected for write or read operations. When 8 or less queues are configured

in the device these flag busses provide an individual flag per queue, when

more than 8 queues are used, either a Polled or Direct mode of bus operation

provides the flag busses with all queues status.

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

or 36 bits wide provided that at least one port is 36 bits wide. When Bus Matching

is used the device ensures the logical transfer of data throughput in a Little

Endian manner.

A packet ready mode of operation is also provided when the device is

configured for 36 bit input and 36 bit output port sizes. The Packet Ready mode

provides the user with a flag output indicating when at least one (or more) packets

of data within a queue is available for reading. The Packet Ready provides the

user with a means by which to mark the start and end of packets of data being

passed through the FIFO queues. The Multi-Queue device then provides the

user with an internally generated packet ready status per queue.

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

to program the total number of queues between 1 and 16, 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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

x9, x18, x36

Qout

OUTPUT

Q0 - Q35

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

5935 drw02

x9, x18, x36

ID0

ID1

ID2

Device ID

3 Bit

PKT

Packet Mode

Logic

JTAG

Logic

D35 = TEOP

D34 = TSOP

Q35 = REOP

Q34 = RSOP

PRn/PAEn

SENO

DFM

MAST

PAE

Upto 16

FIFO

Queues

0.5 Mbit

1.1 Mbit

2.3 Mbit

Dual Port

Memory

OUTPUT

MUX

D0 - D35

Figure 1. Multi-Queue Block Diagram

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 Q19

D17

D18 D19 D8 Q7

D5 Q4D2 Q1

TRST Q0

GND ID2 Q10 Q17 Q18

D20

D21 D22 VCC VCC

VCC VCCVCC VCC

VCC VCC

VCC VCC Q16 Q21 Q20

D23

D24 D25 VCC VCC

VCC VCCVCC VCCVCC VCCGND GND Q24 Q23 Q22

D26

D27 D28 VCC VCCVCC VCCGND GNDGND GNDGND GND Q27 Q26 Q25

D29

D30 D31 VCC VCCVCC VCCGND GNDGND GNDGND GND Q30 Q29 Q28

D32

D33 D34 VCC VCC

GND GNDGND GNDGND GNDGND GND Q33 Q32 Q31

GND

GND D35 VCC VCCGND GNDGND GNDGND GNDGND GND PKT Q35 Q34

GND

GND VCC VCCVCC VCC

GND GNDGND GNDGND GND GND MAST FM

DFM DF VCC VCCVCC VCCGND GNDGND GNDGND GND BM IW OW

SENO

SENI SO VCC VCCVCC VCCVCC VCCVCC VCCGND GND OE RDADD0 RDADD1

WRADD1

WRADD0 SCLK VCC VCCVCC VCCVCC VCCVCC VCCVCC VCC RDADD2 RDADD3 RDADD4

GND

WRADD3 WRADD2 WADEN PAE3PAF3PAE6PAF6PAE7PAF7PAE

FF OV RDADD5 RDADD6 RDADD7

WRADD5

WRADD4 FSYNC FSTR PAE2PAF2PAE5PAF5 DNCPAF4 DNC

PAF PR RADEN ESTR ESYNC

WRADD6

FXI FXO PAF0PAE1PAF1PAE4

WEN REN

WCLK RCLK

PRS MRS PAE0

12 3 4 135126117108 9 14 15 16

5935 drw03

A1 BALL PAD CORNER

EXO EXI

GND

PIN CONFIGURATION

PBGA (BB256-1, order code: BB)

TOP VIEW

NOTE:

1. DNC - Do Not Connect.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 16 FIFO queues in parallel buffering between the two ports. The

user can setup between 1 and 16 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,

independent of one another.

MEMORY ORGANIZATION/ ALLOCATION

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

256 x36 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 256 x36. For the IDT72V51436,

IDT72V51446 and IDT72V51456 the Total Available Memory is 64, 128 and

256 blocks respectively (a block being 256 x36). 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, x18 or x36 bits wide provided that at least

one of the ports is x36 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 a 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 16 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 16 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 8 bits wide. Also, an almost empty flag

status bus is provided, again this bus is 8 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 16 FIFO queues in the device.

In the IDT72V51436/72V51446/72V51456 Multi-Queue FIFO device the

user has the option of utilizing anywhere between 1 and 16 FIFO queues,

therefore the 8 bit flag status busses are multiplexed between the 16 queues,

a flag bus can only provide status for 8 of the 16 queues at any moment, this

is referred to as a “Sector”, such that when the bus is providing status of queues

1 through 8, this is sector 1, when it is queues 9 through 16, this is sector 2. If

less than 16 queues are setup in the device, there are still 2 sectors, such that

in “Polled” mode of operation the flag bus will still cycle through 2 sectors. If for

example only 14 queues are setup, sector 1 will reflect status of queues 1 through

8. Sector 2 will reflect the status of queues 9 through 14 on the least significant

6 bits, the most significant 2 bits of the flag bus are don’t care.

The flag busses are available in two user selectable modes of operation,

“Polled” or “Direct”. When operating in polled mode a flag bus provides status

of each sector sequentially, that is, on each rising edge of a clock the flag bus

is updated to show the status of each sector 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. The mode of operation is always the same for both the

almost full and almost empty flag busses. When operating in direct mode, the

sector on the flag bus is selected by the user. So the user can actually address

the sector to be placed on the flag status busses, these flag busses operate

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.

PACKET READY

The 36 bit Multi-Queue FIFO also offers a ”Packet Ready” mode of operation,

this is user selectable and requires that the device be configured with both write

and read ports as 36 bits wide. The packet mode of operation provides

monitoring of “user marked” locations, when the user is writing data into a FIFO

queue a word being written in can be marked as a “Start of Packet” or “End of

Packet”. Internally as words are being written into the device with markers

attached, the device monitors these markers and provides a packet ready status

flag, which indicates when at least one full packet is available in a queue. The

read port therefore includes an additional status flag, “Packet Ready”, this flag

providing packet ready status for the queue currently selected on the read port

for read operations, indicating when at least one (or more) packets of data are

available to be read. When in packet ready mode the almost empty flag status

bus no longer provides almost empty status for individual sectors, but instead

provides packet ready flag status for individual sectors. (A packet is regarded

as any number of words written between a start of packet and end of packet

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

marker, packet sizes are user defined and sizes are not controlled or limited by

the device).

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 64K x36 deep, 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 a maximum number of 128 (8 x 16) queues may be

setup, each queue being 1K x 36, 2K x 36K, x 36 for the IDT72V51436,

IDT72V51446 and IDT72V51456 respectively. 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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

BM Bus Matching LVTTL This pin is setup before Master Reset and must not toggle during any device operation. This pin is used

INPUT along with IW and OW to setup the FIFO bus width. Please refer to Table 3 for details.

D[35:0] Data Input Bus LVTTL These are the 36 data input pins. Data is written into the device via these input pins on the rising edge

Din INPUT of WCLK provided that WEN is LOW. Note, that in Packet Ready mode D32-D35 may be used as packet

markers, please see packet ready functional discussion for more detail. Due to bus matching not all inputs

may be used, any unused inputs 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

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

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

Strobe INPUT and the RDADD bus to select a sector of queues to be placed on to the PAEn bus outputs. A sector

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

OUTPUT during Polled operation of the PAEn bus. During Polled operation each sector of queue status flags is loaded

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

to PAEn, the second RCLK rising edge loads sector 2. The third RCLK rising edge will again load sector 1.

During the RCLK cycle that sector 1 of a selected device is placed on to the PAEn bus, the ESYNC output

will be HIGH. For sector 2 of that device, the ESYNC output will be LOW.

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

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

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

pin pulses when device N has placed its 2nd sector 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

sector 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

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

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

Strobe INPUT and the WRADD bus to select a sector of queues to be placed on to the PAFn bus outputs. A sector

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

PIN DESCRIPTIONS

Symbol Name I/O TYPE Description

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

PIN DESCRIPTIONS (CONTINUED)

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

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

and SENO has gone LOW.

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

OUTPUT during Polled operation of the PAFn bus. During Polled operation each sector of queue status flags is loaded

on to the PAFn bus outputs sequentially based on WCLK. The first WCLK rising edge loads sector 1 on

to PAFn, the second WCLK rising edge loads sector 2. The third WCLK rising edge will again load sector 1.

During the WCLK cycle that sector 1 of a selected device is placed on to the PAFn bus, the FSYNC output

will be HIGH. For sector 2 of that device, the FSYNC output will be LOW.

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

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

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

pin pulses when device N has placed its 2nd sector 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

sector 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 16Q Multi-Queue device the WRADD and RDADD address busses are 8 bits wide. When a queue

INPUT selection takes place the 3 MSB’s of this 8 bit address bus are used to address the specific device (the

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

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 This pin is used in conjunction with OW and BM to setup the input and output bus widths to be a combination

INPUT of x9, x18 or x36, (providing that one port is x36).

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

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

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

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

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.

Symbol Name I/O TYPE Description

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

OW(1) Output Width LVTTL This pin is setup during Master Reset and must not toggle during any device operation. This pin is used

INPUT in conjunction with IW and BM to setup the data input and output bus widths to be a combination of x9,

x18 or x36, (providing that one port is x36).

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

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/PRn Programmable LVTTL On the 16Q device the PAEn/ PRn bus is 8 bits wide. During a Master Reset this bus is setup for either

Almost-Empty Flag OUTPUT Almost Empty mode or Packet Ready mode. At any one time this output bus provides PAE/ PRn status

Bus/Packet Ready of 8 queues (1 sector), within a selected device, having a total of 2 sectors. During FIFO read/write

Flag Bus operations these outputs provide programmable empty flag status or packet ready status, in either direct

or polled mode. The mode of flag operation is determined during master reset via the state of the FM input.

This flag bus is capable of High-Impedance state, this is important during expansion of Multi-Queue devices.

During direct operation the PAEn/ PRn bus is updated to show the PAE/PR status of a sector of queues

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

the PAEn/ PRn bus is loaded with the PAE/ PRn status of Multi-Queue FIFO sectors sequentially based

on the rising edge of RCLK. PAE or PR operation is determined by the state of PKT during master reset.

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

Almost-Full Flag OUTPUT port for 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 16Q device the PAFn bus is 8 bits wide. At any one time this output bus provides PAF status of

Almost-Full Flag Bus OUTPUT 8 queues (1 sector), within a selected device, having a total of 2 sectors. During FIFO read/write operations

these outputs provide programmable full flag status, in either direct or polled mode. The mode of flag

operation is determined during master reset via the state of the FM input. This flag bus is capable of High-

Impedance state, this is important during expansion of Multi-Queue devices. During direct operation the

PAFn bus is updated to show the PAF status of a sector of 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 sectors sequentially based on the rising edge of WCLK.

PKT(1) Packet Mode LVTTL The state of this pin during a Master Reset will determine whether the part is operating in Packet Ready

INPUT mode providing both a Packet Ready (PR) output and a Programmable Almost Empty (PAE) discrete

output, or standard mode, providing a (PAE) output only. If this pin is HIGH during Master Reset the part

will operate in packet ready mode, if it is LOW then almost empty mode. If packet mode has been selected

the read port flag bus becomes packet ready flag bus, PRn and the discrete packet ready flag, PR is

functional. If almost empty operation has been selected then the flag bus provides almost empty status, PAEn

and the discrete almost empty flag, PAE is functional, the PR flag is inactive and should not be connected.

Packet Ready utilizes user marked locations to identify start and end of packets being written into the device.

Packet Mode can only be selected if both the input port width and output port width are 36 bits.

PR Packet Ready Flag LVTTL If packet ready mode has been selected this flag output provides Packet Ready status of the FIFO queue

OUTPUT selected for read operations. During a master reset the state of the PKT input determines whether Packet

mode of operation will be used. If Packet mode is selected, then the PR flag becomes a valid output, from

which the user can determine if a selected FIFO queue has a “complete” packet of data available for reading.

The user must mark the start of a packet and the end of a packet when writing data into a queue. Using

these Start Of Packet (SOP) and End Of Packet (EOP) markers, the Multi-Queue device sets PR LOW

if one or more “complete” packets are available in the queue.

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

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.

PIN DESCRIPTIONS (CONTINUED)

Symbol Name I/O TYPE Description

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

PIN DESCRIPTIONS (CONTINUED)

Symbol Name I/O TYPE Description

Q[35:0] Data Output Bus LVTTL These are the 36 data output pins. Data is read out of the device via these output pins on the rising edge

Qout OUTPUT of RCLK provided that REN is LOW, OE is LOW and the FIFO queue is selected. Note, that in Packet Ready

mode Q32-Q35 may be used as packet markers, please see packet ready functional discussion for more

detail. Due to bus matching not all outputs may be used, any unused outputs should not be connected.

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

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

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

PAEn/PRn flag sector to be placed on the PAEn/PRn bus during direct flag operation. During polled

flag operation the PAEn/PRn bus is cycled with respect to RCLK and the ESYNC signal is synchronized

to RCLK. The PAE, PR 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 16Q device the RDADD bus is 8 bits. The RDADD bus is a dual purpose address bus. The

[7:0] INPUT first function of RDADD is to select a FIFO queue to be read from. The least significant 4 bits of the bus,

RDADD[3:0] are used to address 1 of 16 possible queues within a Multi-Queue device. Address pin

RDADD[4] provides the user with a Null-Q address. If the user does not wish to address one of the 16

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[7:5] 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 data can be placed on to the Qout bus, read from the previously selected FIFO queue

on this RCLK edge). On the next rising RCLK edge after a read queue select, a data word from the previous

queue will be placed onto the outputs, Qout, regardless of the REN input. Two RCLK rising edges after

read queue select, data will be placed on to the Qout outputs from the newly selected queue, regardless

of REN due to the first word fall through effect.

The second function of the RDADD bus is to select the sector of FIFO queues to be loaded on to the PAEn/

PRn bus during strobed flag mode. The least significant bit, RDADD[0] is used to select the sector of a device

to be placed on the PAEn bus. The most significant 3 bits, RDADD[7:5] are again used to select 1 of 8

possible Multi-Queue devices that may be connected in expansion mode. Address bits RDADD[4:1] are

don’t care during sector selection. The sector 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.

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/PRn bus (in polled mode) or to select the PAEn sector , (in direct mode).

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

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

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

PIN DESCRIPTIONS (CONTINUED)

Symbol Name I/O TYPE Description

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

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.

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

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

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.

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.

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

states.

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

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

INPUT be tied to GND.

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

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

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 flag sector 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.

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 PAFn sector , (in direct mode).

WRADD Write Address Bus LVTTL For the 16Q device the WRADD bus is 7 bits. The WRADD bus is a dual purpose address bus. The first

[6:0] INPUT function of WRADD is to select a FIFO queue to be written to. The least significant 4 bits of the bus,

WRADD[3:0] are used to address 1 of 16 possible queues within a Multi-Queue device. The most significant

3 bits, WRADD[6:4] 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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

PIN DESCRIPTIONS (CONTINUED)

NOTE:

1. Inputs should not change after Master Reset.

Symbol Name I/O TYPE Description

WRADD Write Address Bus LVTTL on the WRADD bus will be selected on a rising edge of WCLK provided that WADEN is HIGH, (note, that

[6:0] INPUT data present on the Din bus can be written into the previously selected FIFO queue on this WCLK edge

(Continued) 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 sector of FIFO queues to be loaded on to the

PAFn bus during strobed flag mode. The least significant bit, WRADD[0] is used to select the sector of a

device to be placed on the PAFn bus. The most significant 3 bits, WRADD[6:4] are again used to select

1 of 8 possible Multi-Queue devices that may be connected in expansion mode. Address bits WRADD[3:1]

are don’t care during sector selection. The sector 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 +3.3V Supply Power These are VCC power supply pins and must all be connected to a +3.3V supply rail.

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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

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 — 100 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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

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

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

5935 drw04

50Ω

VCC/2

I/O Z0 = 50Ω

5935 drw04a

20 30 50 80 100 200

acitance

)

tCD

(Typical, ns)

OUTPUT ENABLE & DISABLE TIMING

AC TEST LOADS

tOE & tOLZ

100mV

tOHZ

100mV

Output

Normally

LOW

Output

Normally

HIGH

VCC/2

5935 drw04b

Output

Enable

Output

Disable

VCC/2

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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

(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)

IDT72V51436L6 IDT72V51436L7-5

IDT72V51446L6 IDT72V51446L7-5

IDT72V51456L6 IDT72V51456L7-5

Symbol Parameter Min. Max. Min. Max. Unit

fCClock Cycle Frequency (WCLK & RCLK) — 166 — 133 MH z

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 — ns

tCLKL Clock Low Time 2. 7 — 3. 5 — n s

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 M Hz

tSCLK Serial Clock Cycle 100 — 100 — ns

tSCKH Serial Clock High 45 — 45 — n s

tSCKL Serial Clock Low 45 — 45 — n s

tSDS Serial Data In Setup 2 0 — 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 — 20 ns

tSENO SCLK to Serial Enable Out — 20 — 20 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.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 (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)

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

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

tPAFLZ(2) WCLK to PAF Flag Bus to Low-Impedance 0.6 3 .7 0 .6 4 ns

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 ns

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

tPR RCLK to Packet Ready Flag 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 PR and OV 6 — 7.5 — ns

tSKEW5 SKEW time between RCLK and WCLK for OV when in Packet 10 — 12 — n s

Ready Mode

tXIS Expansion Input Setup 1.0 — 1.3 — ns

tXIH Expansion Input Hold 0.5 — 0.5 — ns

Commercial Com'l & Ind'l(1)

IDT72V51436L6 IDT72V51436L7-5

IDT72V51446L6 IDT72V51446L7-5

IDT72V51456L6 IDT72V51456L7-5

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

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.

PKT – Packet Mode

FM – Flag bus Mode

IW, OW, BM – 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

IDT72V51436/72V51446/72V51456 devices are capable of up to 16 queues

and therefore contain 16 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 IDT72V51436/72V51446/72V51456 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 IDT72V51436/72V51446/72V51456 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 IDT72V51436/72V51446/72V51456 devices the default mode will

setup 16 queues, each queue being 1024 x36, 2048 x36 and 4,096 x 36 deep

respectively. 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.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

When configuring the IDT72V51436/72V51446/72V51456 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 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 IDT72V51436/72V51446/72V51456 Multi-Queue FIFO devices have

up to 16 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 16 queue Multi-Queue device the WRADD address bus is 7 bits wide.

The least significant 4 bits are used to address one of the 16 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 sector 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[7:0]

Operation WCLK WADEN FSTR WRADD[6:0]

Write Queue

Select

Device Select

(Compared to

ID0,1,2)

Write Queue Address

(4 bits = 16 Queues)

654 32 10

76543 1 0

Device Select

(Compared to

ID0,1,2)

X X X Sector

Address

PAFn Sector

Select

Q0 : Q7 → PAF0 : PAF7

Sector

Address Queue Status on PAFn Bus

1Q8 : Q15 → PAF0 : PAF7

5935 drw05

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

READ QUEUE SELECTION & READ OPERATION

The Multi-Queue FIFO device has up to 8 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 16 queue Multi-Queue device the RDADD

address bus is 8 bits wide. The least significant 4 bits are used to address one

of the 16 available queues within a single Multi-Queue device. The 5th least

significant bit is used to select a "Null" Queue. During a Null-Q selection the 4

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.

Note, the almost empty flag bus becomes the “Packet Ready” flag bus when

the device is configured for packet ready mode, this is discussed in a separate

section of the data sheet.

Operation RCLK RADEN ESTR RDADD[7:0]

Read Queue

Select

Device Select

(Compared to

ID0,1,2)

Read Queue Address

(4 bits = 16 Queues)

7 6 5 4 3210

4321 0

Device Select

(Compared to

ID0,1,2) X X X Sector

Address

PAEn/PRn

Sector

Select

Q0 : Q7 → PAE0 : PAE7

Sector

Address Queue Status on PAEn/PRn Bus

1Q8 : Q15 → PAE0 : PAE7

5935 drw06

Null-Q

Select

TABLE 2 — READ ADDRESS BUS, RDADD[7:0]

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

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[4]. The RDADD[7:0] bus should be addressed with xxx1xxxx,

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 three setup pins, BM

(Bus Matching), 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, 18 bit words and 36 bit long words can be written into and

read form the FIFO queues provided that at least one of the ports is setup for

x36 operation. 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 x36 and the output port is x9, then four 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 x18 and the output port is x36, 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).

BM IW OW Write Port Read Port

0 X X x36 x36

1 0 0 x36 x18

1 0 1 x36 x9

1 1 0 x18 x36

1 1 1 x9 x36

x36 DEVICE

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).

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

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

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

memory depth for that queue. The PAF value of different queues within the same

device can be different values.

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[7:0] 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[7:0] 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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

TABLE 4 — FLAG OPERATION BOUNDARIES & TIMING

Output Valid, OV Flag Boundary

I/O Set-Up OV Boundary Condition

In36 to out36 (Almost Empty Mode) OV Goes LOW after 1st Write

(Both ports selected for same queue (see note 1 below for timing)

when the 1st Word is written in)

In36 to out36 (Packet Ready Mode) OV Goes LOW after 1st Write

(Both ports selected for same queue (see note 2 below for timing)

when the 1st Word is written in)

In36 to out18 OV Goes LOW after 1st Write

(Both ports selected for same queue (see note 1 below for timing)

when the 1st Word is written in)

In36 to out9 OV Goes LOW after 1st Write

(Both ports selected for same queue (see note 1 below for timing)

when the 1st Word is written in)

In18 to out36 OV Goes LOW after 1st Write

(Both ports selected for same queue (see note 1 below for timing)

when the 1st Word is written in)

In9 to out36 OV Goes LOW after 1st Write

(Both ports selected for same queue (see note 1 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

2. OV Timing when in Packet Ready Mode (36 in to 36 out only)

Assertion:

Write to OV LOW: tSKEW4 + RCLK + tROV

If tSKEW4 is violated there may be 1 added clock: tSKEW4 + 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

In36 to out36 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)

In36 to out36 FF Goes LOW after D Writes

(Write port only selected for queue (see note below for timing)

when the 1st Word is written in)

In36 to out18 FF Goes LOW after D Writes

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In36 to out18 FF Goes LOW after D Writes

(Write port only selected for queue (see note below for timing)

when the 1st Word is written in)

In36 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)

In36 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 out36 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)

In18 to out36 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)

In9 to out36 FF Goes LOW after ([D+1] x 4) Writes

(Both ports selected for same queue (see note below for timing)

when the 1st Word is written in)

In9 to out36 FF Goes LOW after (D x 4) Writes

(Write port only selected for queue (see note below for timing)

when the 1st Word is written in)

Programmable Almost Full Flag, PAF & PAFn Bus Boundary

I/O Set-Up PAF & PAFn Boundary

in36 to out36 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)

in36 to out36 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)

in36 to out18 PAF/PAFn Goes LOW after

D-m Writes (see below for timing)

in36 to out9 PAF/PAFn Goes LOW after

D-m Writes (see below for timing)

in18 to out36 PAF/PAFn Goes LOW after

([D+1-m] x 2) Writes

(see note below for timing)

in9 to out36 PAF/PAFn Goes LOW after

([D+1-m] x 4) 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.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

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

in36 to out36 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)

in36 to out36 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)

in36 to out18 PAEn Goes HIGH after n+1

Writes (see below for timing)

in36 to out9 PAEn Goes HIGH after n+1

Writes (see below for timing)

in18 to out36 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)

in18 to out36 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)

in9 to out36 PAEn Goes HIGH after

(Both ports selected for same queue when the 1st ([n+2] x 4) Writes

Word is written in until the boundary is reached) (see note below for timing)

in9 to out36 PAEn Goes HIGH after

(Write port only selected for same queue when the ([n+1] x 4) Writes

1st Word is written in until the boundary is reached) (see note below for timing)

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

in36 to out36 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)

in36 to out18 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)

in36 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)

in18 to out36 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)

in9 to out36 PAE Goes HIGH after

(Both ports selected for same queue when the 1st ([n+2] x 4) Writes

Word is written in until the boundary is reached) (see note below for timing)

PACKET READY FLAG, PR BOUNDARY

Assertion:

Both the rising and falling edges of PR are synchronous to RCLK.

PR Falling Edge occurs upon writing the first TEOP marker, on input D35,

(assuming a TSOP marker, on input D34 has previously been written). i.e. a

complete packet is available within a queue.

Timing:

From WCLK rising edge writing the TEOP word PR goes LOW after: tSKEW4

+ 2 RCLK + tPR

If tSKEW4 is violated:

PR goes LOW after tSKEW4 + 3 RCLK + tPR

(Please refer to Figure 28, Data Input (Transmit) Packet Ready Mode of

Operation for timing diagram).

De-assertion:

PR Rising Edge occurs upon reading the last RSOP marker, from output Q34.

i.e. there are no more complete packets available within the queue.

Timing:

From RCLK rising edge Reading the RSOP word the PR goes HIGH after: 2

RCLK + tPR

(Please refer to Figure 29, Data Output (Receive) Packet Ready Mode of

Operation for timing diagram).

PACKET READY FLAG BUS, PRn BOUNDARY

Assertion:

Both the rising and falling edges of PRn are synchronous to RCLK.

PRn Falling Edge occurs upon writing the first TEOP marker, on input D35,

(assuming a TSOP marker, on input D34 has previously been written). i.e. a

complete packet is available within a queue.

Timing:

From WCLK rising edge writing the TEOP word PR goes LOW after: tSKEW4

+ 2 RCLK* + tPAE

If tSKEW4 is violated PRn goes LOW after tSKEW4 + 3 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.

De-assertion:

PR Rising Edge occurs upon reading the last RSOP marker, from output Q34.

i.e. there are no more complete packets available within the queue.

Timing:

From RCLK rising edge Reading the RSOP word the PR goes HIGH after:

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

PACKET READY FLAG

The Multi-Queue FIFO provides the user with a Packet Ready feature.

During a Master Reset the state of the PKT input (packet ready mode select),

determines whether the device will operate in packet ready mode. A discrete

flag output PR, provides a packet ready status of the active queue, selected on

the read port. A packet ready status is maintained for all queues, however only

the queue selected on the read port has its packet ready status output to the active

PR flag. The PR output flag for the active queue on the read port, is LOW

whenever the active queue has one or more full packets of data within its queue,

available for reading. If less than a full packet is available then the PR flag will

be HIGH, packet not ready. In Packet mode, words cannot be read from a queue

until a complete packet has been written into that queue, regardless of REN.

When packet ready mode is selected the Programmable Almost Empty bus,

PAEn, actually becomes the Packet Ready bus, PRn. The PRn bus now

providing packet ready status for all queues including those not currently

selected on the read port. Both Polled and Direct modes of operation are

available and selectable during a Master Reset.

When the Multi-Queue is selected for packet ready mode the device must also

be configured with a 36 bit write port and 36 bit read port. The two most significant

bits of the 36 bit data bus can now be used as “packet markers”. On the write

port these are bits D34, D35 and on the read port Q34, Q35. All four bits are

monitored by the packet control logic as data is written into and read out from

the FIFO queues. The packet ready status for individual queues is then

determined by the packet ready logic.

On the write port D34 is used to “mark” the word currently being written into

the selected FIFO queue as a “Transmit Start of Packet”, TSOP. When the user

requires a word being written in to be marked as the start of a packet, the TSOP

input must be HIGH for the same WCLK rising edge as the word that is written

in. This marker is effectively a “tag” on the end of the word to be marked as it

is being written in to its respective queue. This TSOP marker will remain stored

in the FIFO queue along with the data it was written in with until the word in turn

is read out of the queue via the read port. This marker will be read out on Q34

and is now denoted with the name, “Receive Start of Packet”, RSOP.

The second marker that is used on the write port is D35 and is used to “mark”

the word currently being written into the selected FIFO queue as a “Transmit

End of Packet”, TEOP. When the user requires a word being written in to be

marked as the end of a packet, the TEOP input must be HIGH for the same WCLK

rising edge as the word that is written in. This marker is effectively a “tag” on the

end of the word to be marked as it is being written in to its respective queue. This

TEOP marker will remain stored in the FIFO queue along with the data it was

written in with until the word in turn is read out of the queue via the read port.

This marker will be read out on Q35 and is now denoted with the name, “Receive

End of Packet”, REOP.

The packet ready logic monitors all start and end of packet markers both as

they enter respective queues via the write port and as they exit queues via the

read port. The logic both increments and decrements a packet counter, which

is provided for each queue. This functionality of the packet ready logic means

that status is provided as to whether or not at least one full packet of data is

available within a respective queue. For example, if a TSOP has been received

and some time later a TEOP is received a full packet of data is deemed to be

available, and the PR flag will go active LOW. Consequently if reads begin from

that queue and the RSOP is detected on the output port as data is being read

out, then there is no longer deemed to be a full packet of data available and PR

will go inactive HIGH provided, that no other full packets are available.

Essentially, a partial packet in a queue is regarded as a packet not being ready

and PR will be HIGH. In Packet mode, words cannot be read from a queue until

a complete packet has been written into that queue, regardless of REN. In Packet

mode the Multi-Queue device will prevent reads from a selected queue until a

TSOP marker followed (at some later time), by a TEOP marker has been written.

The PR flag will go active LOW to indicate that a complete packet is available

within the queue. Once the RSOP marker is read out, the PR flag will go HIGH,

indicating that a complete packet is no longer present, (assuming that there are

no more packets in the queue). The user may proceed with the reading

operation until the current packet has been read out and no further complete

packets are available. If during that time another complete packet has been

written into the queue and the PR flag has again gone active, then reads from

the new packet may follow after the current packet has been completely read out.

The packet counters therefore look for start of packet markers followed by end

of packet markers and regard data in between the TSOP and TEOP as a full

packet of data. The packet monitoring has no limitation as to how many packets

are written into a FIFO queue, the only constraint of course being the depth of

the queue. Note, that there is a minimum allowable packet size of four writes, that is

within a TSOP marker and TEOP marker there must be two other write operations.

The packet logic does expect a TSOP marker to be followed by a TEOP

marker.

If a second TSOP marker is read after a first, then it is ignored and the logic

regards data between the first TSOP and the first subsequent TEOP as the full

packet. The same is true for TEOP, a second consecutive TEOP mark is ignored.

On the write side the 2nd consecutive TSOP and TEOP is ignored. On the read

side the user should regard a packet as being between the first RSOP and the

first subsequent REOP.

The user may also wish to implement the use of an “Almost End of Packet”

marker, AEOP. For example, the AEOP can be set on input D33, and this will

pass straight through the FIFO queue, remaining attached as a “tag” to the 36

bit long word it was written with, being read out on Q33. The purpose of this AEOP

marker is to provide the entity reading data from the Multi-Queue device that the

end of packet is a fixed (known) number of reads away from the end of packet.

This is a useful feature when due to latencies within the system, monitoring the

REOP marker alone does not prevent “over reading” of the data from the queue

selected. For example, an AEOP marker set 4 writes before the TEOP marker

provides the device connected to the read port with and “almost end of packet”

indication 4 cycles before the end of packet.

The AEOP can be set any number of words before the end of packet

determined by the user requirements or latencies involved in the system.

Ideally a switch should be performed one cycle before the TEOP is read out.

So on the next cycle the last word of a packet (TEOP) is read, and on the following

cycle the next word of the new queue is read out. Once a packet is being read

out it must be read to completion. That is, the user cannot switch to a new queue

in the middle of a packet being read out. For example, when the RSOP marker

is read out of a queue, marking the start of Packet, that packet must be read to

completion, until its associated REOP, (End of Packet Marker) has been read

out, again the queue switch taking place one cycle before the "End of Packet"

is read out.

See Figure 28, Data Input (Transmit) Packet Ready Mode of Operation and

Figure 29, Data Output (Receive) Packet Ready Mode of Operation.

PACKET READY – MODULO OPERATION

When utilizing the Multi-Queue FIFO device in Packet Ready mode, the user

may also want to consider the implementation of “Modulo” operation or “valid

byte marking”. This may be a requirement when the packets being transferred

through a FIFO queue are in a byte arrangement even though the data bus

width is 36 bits. Here the user may actually be concatenating bytes to form a 36

bit data bus through the Multi-Queue device. In this situation only a limited number

of bytes may actually be part of the packet. This will only occur when the first

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

36 bit long word of a packet is written in and the last 36 bit long word of packet

is written in. The modulo operation is a means by which the user can mark and

identify which bytes of a 36 bit long word are part of the packet.

On the write port data input bits, D32 (transmit modulo bit 2, TMOD2) and D33

(transmit modulo bit 1, TMOD1) can be used to code which bytes of a word are

part of the packet that is also being marked as the “Start of Packet” or “End of

Packet”. Conversely on the read port when reading out these marked words,

data outputs Q32 (receive modulo bit 2, RMOD2) and Q33 (receive modulo bit

1, RMOD1) will pass on the byte validity information for that long word. Refer

to Table 5 for an example of how the modulo bits may be setup and used. See

Figure 28, Data Input (Transmit) Packet Ready Mode of Operation and Figure

29, Data Output (Receive) Packet Ready Mode of Operation.

The internal packet ready control logic performs no operation on these

Modulo bits, they are purely informational bits that are passed through a queue

with the respective data bytes.

PAFn FLAG BUS OPERATION

The IDT72V51436/72V51446/72V51456 Multi-Queue FIFO device can be

configured for up to 16 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 8 bits wide,

so that 8 queues at a time can have their status output to the bus. If 8 or less queues

are setup within a device then each queue will have its own dedicated output

from the bus, if more than 8 queues are setup then there are 2 methods by which

the device can share the bus between queues, “Direct” mode and “Polled” mode

depending on the state of the FM (Flag Mode) input during a Master Reset.

PAFn - DIRECT BUS

If FM is LOW at master reset then the PAFn bus operates in Direct (addressed)

mode. In direct mode the user can address the sector of queues they require

to be placed on to the PAFn bus. For example, consider the operation of the

PAFn bus when 10 queues have been setup. To output status of the first sector,

Queue[0:7] the WRADD bus is used in conjunction with the FSTR (PAF flag

strobe) input and WCLK. The address present on the significant bit of the

WRADD bus with FSTR HIGH will be selected as the sector address on a rising

edge of WCLK. So to address sector 1, Queue[0:7] the WRADD bus should be

loaded with “xxxxxx0”, the PAFn bus will change status to show the new sector

selected 1 WCLK cycle after sector selection. PAFn[0:7] gets status of queues,

Queue[0:7] respectively.

To address the second sector, Queue[8:15], the WRADD address is

“xxxxxx1”. PAF[0:1] gets status of queues, Queue[9:10] respectively. Remem-

ber, only 10 queues were setup, so when sector 2 is selected the unused outputs

PAF[2:7] will be don't care states.

Note, that if a read or write operation is occurring to a specific queue, say

queue ‘x’ on the same cycle as a sector switch which will include the 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.

Sectors can be selected on consecutive clock cycles, that is the sector on 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 WCLK rising edge that a sector

is being selected, the only restriction being that a write queue selection and PAFn

sector selection cannot be made on the same cycle.

If 8 or less queues are setup then queues, Queue[0:7] have their PAF status

output on PAF[0:7] constantly.

When the Multi-Queue devices are connected in expansion of more than one

device the PAFn busses of all devices are connected together, when switching

between sectors of different devices the user must utilize the 3 most significant

bits of the WRADD address bus (as well as the 2 LSB’s). These 3 MSB’s

correspond to the device ID inputs, which are the static inputs, ID0, ID1 & ID2.

Please refer to Figure 23

PAF

n - Direct Mode Sector Selection for timing

information. Also refer to Table 1, Write Address Bus, WRADD.

PAFn – POLLED BUS

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 2 sectors

within the device regardless of how many queues have been setup in the part.

BYTE ABYTE BBYTE CBYTE D

D0/Q0

D35/Q35

TMOD1 (D33)

RMOD1 (Q33)

TMOD2 (D32)

RMOD2 (Q32) VALID BYTES

0 0 A, B, C, D

01A

1 0 A, B

1 1 A, B, C

D15/Q15

D23/Q23

D31/Q31

D34/Q34

D33/Q33

D32/Q32

MOD 2

MOD 1

SOP

EOP

D7/Q7

5935 drw07

TABLE 5 — PACKET MODE VALID BYTE

NOTE:

Packet Mode is only available when the Input Port and Output Port are 36 bits wide.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Every rising edge of the WCLK causes the next sector to be loaded on the PAFn

bus. The device configured as the master (MAST input tied HIGH), will take

control of the PAFn after MRS goes LOW. For the whole WCLK cycle that the

first sector is on PAFn the FSYNC (PAFn bus sync) output will be HIGH, for the

2nd sector, this FSYNC output will be LOW. This FSYNC output provides the

user with a mark with which they can synchronize to the PAFn bus, FSYNC is

always HIGH for the WCLK cycle that the first sector of a device is present on

the PAFn bus.

When devices are connected in expansion mode, only 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

will place its first sector on the bus on the rising edge of WCLK after the MRS

input goes HIGH. For the next 3 WCLK cycles the master device will maintain

control of the PAFn bus and cycle its sectors through it, all other devices hold

their PAFn outputs in High-Impedance. When the master device has cycled its

sectors it passes a token to the next device in the chain and that device assumes

control of the PAFn bus and then cycles its sectors and so on, the PAFn bus

control token being passed on from device to device. This token passing is done

via the FXO outputs and FXI inputs of the devices (“PAF Expansion Out” and

“PAF Expansion In”). The FXO output of the master device connects to the FXI

of the second device in the chain and the FXO of the second connects to the FXI

of the third and so on. The final device in a chain has its FXO connected to the

FXI of the first device, so that once the PAFn bus has cycled through all sectors

of all devices, control of the PAFn will pass to the master device again and so

on. The FSYNC of each respective device will operate independently and

simply indicate when that respective device has taken control of the bus and is

placing its first sector on to the PAFn bus.

Please refer to Figure 26,

PAF

n Bus – Polled Mode for timing information.

PAEn/PRn FLAG BUS OPERATION

The IDT72V51436/72V51446/72V51456 Multi-Queue FIFO device can be

configured for up to 16 FIFO queues, each queue having its own almost empty/

packet ready status. An active queue has its flag status output to the discrete flags,

OV, PAE and PR, on the read port. Queues that are not selected for a read

operation can have their PAE/PR status monitored via the PAEn/PRn bus. The

PAEn/PRn flag bus is 8 bits wide, so that 8 queues at a time can have their status

output to the bus. If 8 or less queues are setup within a device then each queue

will have its own dedicated output from the bus, if more than 8 queues are setup

then there are 2 methods by which the device can share the bus between

queues, “Direct” mode and “Polled” mode depending on the state of the FM

(Flag Mode) input during a Master Reset.

PAEn/PRn - DIRECT BUS

If FM is LOW at master reset then the PAEn/PRn bus operates in Direct

(addressed) mode. In direct mode the user can address the sector of queues

they require to be placed on to the PAEn/PRn bus. For example, consider the

operation of the PAEn/PRn bus when 10 queues have been setup. To output

status of the first sector, Queue[0:7] the RDADD bus is used in conjunction with

the ESTR (PAE/PR flag strobe) input and RCLK. The address present on the

least significant bit of the RDADD bus with ESTR HIGH will be selected as the

sector address on a rising edge of RCLK. So to address sector 1, Queue[0:7]

the RDADD bus should be loaded with “xxxxxx0”, the PAEn/PRn bus will

change status to show the new sector selected 1 RCLK cycle after sector

selection. PAEn[0:7] gets status of queues, Queue[0:7] respectively.

To address the second sector, Queue[8:15], the RDADD address is

“xxxxxx1”. PAE[0:1] gets status of queues, Queue[9:10] respectively. Remem-

ber, only 10 queues were setup, so when sector 2 is selected the unused outputs

PAE[2:7] will be don't care states.

Note, that if a read or write operation is occurring to a specific queue, say

queue ‘x’ on the same cycle as a sector switch which will include the 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/PRn bus.

Sectors can be selected on consecutive clock cycles, that is the sector on the

PAEn/PRn bus can change every RCLK cycle. Also, data can be read out of

a FIFO queue on the same RCLK rising edge that a sector is being selected,

the only restriction being that a read queue selection and PAEn/PRn sector

selection cannot be made on the same RCLK cycle.

If 8 or less queues are setup then queues, Queue[0:7] have their PAE/PR

status output on PAE[0:7] constantly.

When the Multi-Queue devices are connected in expansion of more than one

device the PAEn/PRn busses of all devices are connected together, when

switching between sectors of different devices the user must utilize the 3 most

significant bits of the RDADD address bus (as well as the 2 LSB’s). These 3

MSB’s correspond to the device ID inputs, which are the static inputs, ID0, ID1

& ID2.

Please refer to Figure 22,

PAE

n - Direct Mode Sector Selection for

timing information. Also refer to Table 2, Read Address Bus, RDADD.

PAEn – POLLED BUS

If FM is HIGH at master reset then the PAEn/PRn bus operates in Polled

(looped) mode. In polled mode the PAEn/PRn bus automatically cycles through

the 2 sectors within the device regardless of how many queues have been setup

in the part. Every rising edge of the RCLK causes the next sector to be loaded

on the PAEn/PRn bus. The device configured as the master (MAST input tied

HIGH), will take control of the PAEn/PRn after MRS goes LOW. For the whole

RCLK cycle that the first sector is on PAEn/PRn the ESYNC (PAEn/PRn bus

sync) output will be HIGH, for the 2nd sector, this ESYNC output will be LOW.

This ESYNC output provides the user with a mark with which they can

synchronize to the PAEn/PRn bus, ESYNC is always HIGH for the RCLK cycle

that the first sector of a device is present on the PAEn/PRn bus.

When devices are connected in expansion mode, only 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/PRn bus

and will place its first sector on the bus on the rising edge of RCLK after the MRS

input goes LOW. For the next 3 RCLK cycles the master device will maintain

control of the PAEn/PRn bus and cycle its sectors through it, all other devices

hold their PAEn/PRn outputs in High-Impedance. When the master device has

cycled its sectors it passes a token to the next device in the chain and that device

assumes control of the PAEn/PRn bus and then cycles its sectors and so on,

the PAEn/PRn bus control token being passed on from device to device. This

token passing is done via the EXO outputs and EXI inputs of the devices (“PAE

Expansion Out” and “PAE Expansion In”). The EXO output of the master device

connects to the EXI of the second device in the chain and the EXO of the second

connects to the EXI of the third and so on. The final device in a chain has its EXO

connected to the EXI of the first device, so that once the PAEn/PRn bus has cycled

through all sectors of all devices, control of the PAEn/PRn will pass to the master

device again and so on. The ESYNC of each respective device will operate

independently and simply indicate when that respective device has taken control

of the bus and is placing its first sector on to the PAEn/PRn bus.

Please refer to Figure 27,

PAE

n Bus – Polled Mode for timing

information.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

1st: Read from FIFO Queue

2nd: Read from FIFO Queue

3rd: Read from FIFO Queue

4th: Read from FIFO Queue

5935 drw08

Q35-Q27 Q26-Q18 Q17-Q9 Q8-Q0

(a) x36 INPUT to x36 OUTPUT

(b) x36 INPUT to x18 OUTPUT

Read from FIFO Queue

BM IW OW

1st: Read from FIFO Queue

2nd: Read from FIFO Queue

BYTE ORDER ON OUTPUT PORT:

Q35-Q27 Q26-Q18 Q17-Q9 Q8-Q0

1st: Write to FIFO Queue

2nd: Write to FIFO Queue

3rd: Write to FIFO Queue

4th: Write to FIFO Queue

BYTE ORDER ON INPUT PORT:

DCB A

(e) x9 INPUT to x36 OUTPUT

Read from FIFO Queue

BYTE ORDER ON OUTPUT PORT:

D35-D27 D26-D18 D17-D9 D8-D0

Q35-Q27 Q26-Q18 Q17-Q9 Q8-Q0

D35-D27 D26-D18 D17-D9 D8-D0

(d) x18 INPUT to x36 OUTPUT

Read from FIFO Queue

BYTE ORDER ON INPUT PORT:

D35-D27 D26-D18 D17-D9 D8-D0

1st: Write to FIFO Queue

2nd: Write to FIFO Queue

BYTE ORDER ON OUTPUT PORT:

D35-D27 D26-D18 D17-D9 D8-D0

ABC D

Write to FIFO Queue

BYTE ORDER ON INPUT PORT:

BM IW OW

Figure 3. Bus-Matching Byte Arrangement

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

tRSF

PAF

tRSF

PAE

tRSF

LOGIC "1" if OE is LOW and device is Master

HIGH-Z if OE is HIGH or Device is Slave

HIGH-Z if Slave Device

LOGIC “0" if Master Device

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

LOGIC "1" if Master Device

HIGH-Z if Slave Device

LOGIC "1" if Master Device

HIGH-Z if Slave Device

PAFn

PAEn

PRn

tRS

MRS

WEN

REN

tRSS

FSTR,

ESTR

5935 drw09

tRSR

SENI

WADEN,

RADEN

tRSS

OW, IW,

HIGH = Looped

LOW = Strobed (Direct)

ID0, ID1,

ID2

tRSS

HIGH = Packet Ready Mode

LOW = Almost Empty

MAST

PKT

DFM

HIGH = Master Device

LOW = Slave Device

HIGH = Default Programming

LOW = Serial Programming

HIGH = Offset Value is 128

LOW = Offset value is 8

tRSS

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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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

5935 drw11

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

5935 drw10

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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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

5935 drw12

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)

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 IDT72V51436/72V51446/72V51456.

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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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

5935 drw12a

WFF

ENS

ROV

PCWQ

PCRQ

HIGH - Z

(Slave Device)

SENO

(MQ1)

SENO

(MQ2)

SENO

(MQ8)

SENO

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

SENO

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 Qx

WFF

5935 drw13

WEN

ENS

tQHtQS

tDHtDS

D-2

D-1

tDH

Din

tWFF tWFF

Previous Q Status

No Writes

FIFO Queue Full

*A* *B* *C* *D* *E* *F* *G*

tDS

tDS tDH

tENH

tWFF tWFF

RCLK

tSKEW1

tQS tQH

REN

tENS

RDADD

RADEN

Qout

Previous Q, Word, W Previous Q, W+1

PFT

Qy, W0

PFT

tAtA

Qy, W1Qy, W2

*H* *I* *J*

tAS tAH

*AA* *BB* *CC* *DD* *EE* *FF*

tDS

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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

5935 drw13a

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

WCLK

WADEN

WRADD

(Device 1)

FFLZ

5935 drw14

WEN

ENS

1 Q12

Din

WFF

HIGH-Z

RCLK

ENH

ENS

ENH

Addr=001

1100

WFF

1 Q5

FFHZ

WFF

HIGH-Z

(Device 2)

FFHZ

HIGH-Z

FFLZ

SKEW1

Addr=001

0101

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*

Figure 11. Full Flag Timing in Expansion Mode

NOTE:

1. REN = HIGH.

Cycle:

*A* Queue, Q12 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, Q5 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 Q12 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 Q12 of D1. This write operation causes Q12 to go full, FF goes LOW.

*CC* The first word from Q5 of D1 selected on cycle *AA* is read out, this occurred regardless of REN due to FWFT. This read caused Q5 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, Q5 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 Q5, it is not full, FF goes HIGH.

*F* Word, Wd is written into Q5 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 Q5 of D1 on cycle *CC*. (This read is not an enabled read, it is due to the FWFT operation).

*I* Queue, Q9 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 Q9 of D2.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

Figure 12. Read Queue Select, Read Operation

RCLK

5935 drw15

RDADD

RADEN

REN

ENS

ENH

ENS

OUT

n-3

n-2

Previous Q, Q

n-1

PFT

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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)

5935 drw16

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

Q9 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*

Cycle:

*A* Queue 9 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 Q9 of D1. This happens to be the last word of Q9. 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 Q9 is valid.

*D* Queue 15 of device 1 is selected for read operations. The last word of Q9 was read on the previous cycle, therefore OV goes HIGH to indicate that the data on the Qout is

not valid (Q9 was read to empty). Word, Wd remains on the output bus.

*E* The last word of Q9 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, Q15 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 Q15, this queue is now empty.

*H* The OV flag goes HIGH to indicate that Q15 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 Q15. The latency is: tSKEW1 + 1*RCLK + tROV.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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

5935 drw17

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

5935 drw18

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

RCLK

RADEN

Qout

REN

tAH

tAS

0001xxxx

RDADD

NULL QUEUE

SELECT

*A* *B* *C* *E* *F*

tQH

tENS

Q1 Wn-3 Q1 Wn-2 Q1 Wn-1

tAtA

Q1 Wn

Q4 W0

FWFT

tROV tROV

5935 drw19

SELECT

NEW QUEUE

*D*

00000100

tAHtAS

tQHtQS

tENH

tQS

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 (32nd queue) 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, Q4 is selected and the 1st word of Q4 will fall through present on the O/P register on cycle *F*.

5935 drw20

Queue 1

Memory

*A*

Null

Queue

*B*

Null

Queue

*C*

O/P Reg.

*D* *E* *F*

Null

Queue

Queue 4

Memory

Queue 4

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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

WCLK

WADEN

tQHtQS

tAHtAS

WRADD

D1 Q5

PAF

(Device 1)

tAFLZ

5935 drw21

WEN

tENS

tAHtAS

tQH

tQS

tDH

tDS

WD-m

Din

tWAF tWAF

HIGH-Z

tENH

D1 Q9

PAF

(Device 2)

tFFHZ

D1 Q5

*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

5935 drw22

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 5 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 Q5 causing the PAF flag to go from HIGH to LOW. The flag latency is 2 WCLK cycles + tWAF.

*D* Queue 9 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 Q9.

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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 Q12

PAE

(Device 1)

AELZ

5935 drw23

REN

OLZ

Qout

RAE

HIGH-Z

D1 Q15

PAE

(Device 2)

AEHZ

HIGH

HIGH-Z

D1 Q12 Wn

HIGH-Z

*B* *C* *E* *F**D**A*

D1 Q30 Wn+1

D1 Q15 W0

D1 Q15 W1

*G*

WCLK

ENH

CLKH

CLKL

WEN

PAE

RCLK

ENS

n+1 words in FIFO

RAE

SKEW2

RAE

REN

5935 drw24

ENS

ENH

n+2 words in FIFO n+1 words in FIFO

Cycle:

*A* Queue 12 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 Q12 due to the FWFT operation. This read operation from Q12 is at the almost empty boundary, therefore

PAE will go LOW 2 RCLK cycles later.

*D* Q15 of device 1 is selected.

*E* The PAE flag goes LOW due to the read from Q12 2 RCLK cycles earlier. Word Wn+1 is read out due to the FWFT operation.

*F* Word, W0 is read from Q15 due to the FWFT operation. The PAE flag goes HIGH to show that Q15 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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

Figure 22.

PAE

n - Direct Mode - Sector Selection

RCLK

STH

STS

001xxxx1

5935 drw25

RDADD

ESTR

Device 1

Sector 2

001xxxx0

Device 1

Sector 1

001xxxx1

Device 1

Sector 2

STS

STH

PAEn/

PRn

PAE

Device 1 Sector 2 Device 1 Sector 1

PAE

Device 1 Sector 2

Figure 23.

PAF

n - Direct Mode - Sector Selection

WCLK

tSTHtSTS

tQHtQS

001xxx0

5935 drw26

WRADD

FSTR

Device 1

Sector 1

tQS tQH

001xxx1

Device 1

Sector 2

tQS tQH

001xxx0

Device 1

Sector 1

tSTS tSTH

PAFn

tPAF tPAF

Device 1 Sector 1 Device 1 Sector 3

tPAF

Device 1 Sector 1

NOTES:

1. Sectors can be selected on consecutive cycles.

2. On an RCLK cycle that the ESTR is HIGH, the RADEN input must be LOW.

3. There is a latency of 1 RCLK for the PAEn bus to switch.

NOTES:

1. Sectors can be selected on consecutive cycles.

2. On a WCLK cycle that the FSTR is HIGH, the WADEN input must be LOW.

3. There is a latency of 1 WCLK for the PAFn bus to switch.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

WCLK

Prev PAEn

RCLK

ESTR

RDADD

D5 Sect 2

101 xxxx1100 00100

D5Q4

SKEW3

Previous value loaded on to PAE bus

xxxx xxx0

D5 Sect 2

RADEN

STH

STS

PAE

5935 drw27

Device 5 PAE

RAE

*AA* *BB* *CC* *DD* *FF**EE*

RAE

D5 Qn Status

xxxx xxx0

D5 Sect 2

Bus PAEnPrevious value loaded on to PAE bus

D5 Sect 2

PAEHZ

PAEZL

xxxx xxx1

REN

ENH

ENS

Device 5 -Qn Wy

D5 Q4

Wy+1

D5 Q4

Wy+3

D5 Q4

Wy+2

D5 Q4

Wa+1

D5 Qn

WEN

WADEN

FSTR

100 0100

WRADD D5Q4 D3Q8

D5 Q4

Wn+1

D5Q4

D3 Q8

011 01000

D4 Sect 1

100 xxx0

*A* *B* *C* *D* *E* *F*

ENS

ENH

STH

STS

Device 5 PAEn

ENS

ENH

Wp+1

Writes to Previous Q

RAE

D5 Q4

status

Figure 24.

PAE

n - Direct Mode, Flag Operation

Cycle:

*A* Queue 4 of Device 5 is selected for write operations.

Word, Wp is written into the previously selected queue.

*AA* Queue 4 of Device 5 is selected for read operations.

A sector from 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 Qn of D5, due to FWFT operation.

*C* Word, Wn is written into the newly selected queue, Q4 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, Q4 will be read out due to FWFT operation.

Sector 2 of Device 5 is selected on the PAEn bus. Q4 of device 5 will therefore have is PAE status output on PAE[0]. There is a single RCLK cycle latency before

the PAEn bus changes to the new selection.

*D* Queue 8 of Device 3 is selected for write operations.

Word Wn+1 is written into Q4 of D5.

*DD* The PAEn bus changes control to D5, the PAEn outputs of D5 go to Low-Impedance and sector 2 is placed onto the outputs. The device of the previously selected

sector now places its PAEn outputs into High-Impedance to prevent bus contention. Word, Wy+1 is read from Q4 of D5.

The discrete PAE flag will go HIGH to show that Q4 of D5 is not almost empty. Q4 of device 5 will have its PAE status output on PAE[0].

*E* No writes occur.

*EE* Word, Wy+2 is read from Q4 of D5.

*F* Sector 1 of device 4 is selected on the write port for the PAFn bus.

Word, Wx is written into Q8 of D3.

*FF* The PAEn bus updates to show that Q4 of D5 is almost empty based on the reading out of word, Wy+1.

The discrete PAE flag goes LOW to show that Q4 of D5 is almost empty based on the reading of Wy+1.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

RCLK

tOLZ

REN

RADEN

ESTR

WRADD

tAH

000 01111

tAS

RDADD D0Q16

D0 Q16

111 xxxx0

D7 sect 1

110 00010

*A* *B* *C* *D* *E* *F*

000 xxx1

tQH

tQS tQH

tQS

tAH

tAS

tSTH

tSTS

tSTH

tSTS

5935 drw28

*AA*

0xxx xxxx

D0Sect2

Device 0 PAFn

Bus PAFn

*BB* *CC* *DD* *EE* *FF*

tPAFLZ

1xxx xxxx

D0Sect2 D0Sect2

tPAF tPAF

0xxx xxxx

D0Sect2 1xxx xxxx

D0Sect2 D0Sect2 0xxx xxxxDXQuad y

Prev. PAFnDXQuad y

tPAFHZ

HIGH-Z

Device 0 PAF HIGH - Z

tPAFLZ tWAF

Qout

D6Q2

Prev. Q

WD-M+1

D0 sect2

FSTR

WCLK

tSKEW3

WX +1

Prev. Q

D0 Q16

WEN

tENS

WADEN

tQHtQS

tAHtAS tAH

tAS

WD - M + 2

*G*

D0 Q16

D6 Q2

tENH

Din

tDS tDH tDS tDH tDS tDH

Word Wy

D0 Q16

Wy+1

D0 Q16

Wy+2

D0 Q16

Figure 25.

PAF

n - Direct Mode, Flag Operation

Cycle:

*A* Queue 16 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* Sector 2 of device 0 is selected for the PAFn bus. The bus is currently providing status of a previously selected sector, Sect Y of device X.

*B* Word, Wx+1 is read out from the previous queue due to the FWFT effect.

*BB* Queue 16 of device 0 is selected on the write port.

The PAFn bus is updated with the sector selected on the previous cycle, D0 Sect 2. PAF[7] is LOW showing the status of queue 16.

The PAFn outputs of the device previously selected on the PAFn bus go to High-Impedance.

*C* A new sector, Sect 1 of Device 7 is selected for the PAFn bus.

Word, Wd-m+1 is read from Q16 D0 due to the FWFT operation. This read is at the PAFn boundary of queue D0 Q16. This read will cause the PAF[7] 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 Sect 2 D0.

*D* No read operations occur, REN is HIGH.

*DD* PAF[7] goes HIGH to show that D0 Q16 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 Q16.

*E* Queue 2 of Device 6 is selected for write operations.

*EE* Word, Wy+1 is written into D0 Q16.

*F* Word, Wd-m+2 is read out due to FWFT operation.

*FF* PAF[7] and the discrete PAF flag go LOW to show the write on cycle *DD* causes Q16 of D0 to again go almost full.

Word, Wy+2 is written into D0 Q16.

*G* Word, W0 is read from Q0 of D6, selected on cycle *E*, due to FWFT.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

Figure 27.

PAE

n Bus - Polled Mode

WCLK

5935 drw29

FSYNC

FSYNC0

(MASTER) t

FXO

FSYNC

FXO

FSYNC

FXO

FXO0 /

FXI1

FSYNC1

(SLAVE)

FXO1 /

FXI2

FSYNC2

(SLAVE)

FXO2 /

FXI0

PAFn

PAF

FSYNC

D0Sect1 D0Sect2 D0Sect1 D1Sect2 D2Sect1 D2Sect2 D0Sect1

Figure 26.

PAF

n Bus - Polled Mode

NOTE:

1. This diagram is based on 3 devices connected in expansion mode.

NOTE:

1. This diagram is based on 3 devices connected in expansion mode.

RCLK

5935 drw30

ESYNC

ESYNC0

EXO

ESYNC

EXO

ESYNC

EXO

EXO0 /

EXI1

ESYNC1

EXO1 /

EXI2

ESYNC2

EXO2 /

EXI0

PAEn

PAE

ESYNC

D0Sect1 D0Sect2 D0Sect1 D1Sect2 D2Sect1 D2Sect2 D0Sect1

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

ENS

*A* *B*

ENH

P1Wo P1Wn

P1Wn-1

P1Wn-2

P1Wn-3

*C*

WCLK

TSOP

(D34)

RCLK

TEOP

(D35)

WEN

D0-D31

TAEOP/ TMOD1

(D33)

TMOD2

(D32)

5935 drw31

ROV

P1Wo

SKEW5

Last Word Read Out

SKEW4

Figure 28. Data Input (Transmit) Packet Ready Mode of Operation

NOTES:

1. REN is HIGH.

2. If tSKEW4 is violated PR may take one additional RCLK cycle.

3. If tSKEW5 is violated the OV may take one additional RCLK cycle.

4. PR will always go LOW on the same cycle or 1 cycle ahead of OV going LOW, (assuming the last word of the packet is the last word in the FIFO queue).

5. In Packet mode, words cannot be read from a queue until a complete packet has been written into that queue, regardless of REN.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

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

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

RSOP

(Q34)

REOP

(Q35)

ENS

REN

Q0-Q31 P1Wo P1Wn

P1W1

RAEOP/ RMOD1

(Q33)

RMOD2

(Q32)

RCLK

P1Wn

-1

P1Wn

-2

P1Wn

-3

*A* *B* *D* *E*

5935 drw32

ROV

P1W2

*C*

Figure 29. Data Output (Receive) Packet Ready Mode of Operation

NOTE:

1. In Packet mode, words cannot be read from a queue until a complete packet has been written into that queue, regardless of REN.

2. The PR flag will go HIGH on cycle *C* regardless of REN.

3. The OV flag will go HIGH (preventing further reads), when the last complete packet has been read out. If there is a partial packet (an incomplete packet) in the queue the OV flag will remain HIGH until further writes have

completed the packet.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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-Q35

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

DONE

5935 drw33

D0-D35

Q0-Q35

D0-D35

D0-D35 Q0-Q35

SENI

PR Packet Reads

Serial Enable

SENO

SENI

Figure 30. 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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 5935 drw34

JTAG INTERFACE

Five additional pins (TDI, TDO, TMS, TCK and TRST) are provided to

support the JTAG boundary scan interface. The IDT72V51436/72V51446/

72V51456 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 31. 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

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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

5935 drw35

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 32. 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.

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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 IDT72V51436/72V51446/72V51456, the Part Number field con-

tains the following values:

Device Part# Field (HEX)

IDT72V51436 0x43B

IDT72V51446 0x43C

IDT72V51456 0x43D

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

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.

COMMERCIAL AND INDUSTRIAL

TEMPERATURE RANGES

IDT72V51436/72V51446/72V51456 3.3V, MULTI-QUEUE FIFO (16 QUEUES)

36 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)

5935 drw36

Figure 33. Standard JTAG Timing

SYSTEM INTERFACE PARAMETERS

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)

IDT72V51436

IDT72V51446

IDT72V51456

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 -

NOTE:

1. 50pf loading on external output signals. NOTE:

1. Guaranteed by design.

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 emai l: F IFOhelp@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

5935 drw37

Commercial Only

Com’l & Ind’l

IDT XXXXX

Device Type

Power

Speed

Package

Process /

Temperature

Range

BLANK

I(1)

72V51436 589,824 bits  3.3V Multi-Queue FIFO

72V51446 1,179,648 bits  3.3V Multi-Queue FIFO

72V51456 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 available by special order.

DATASHEET DOCUMENT HISTORY

10/12/2001 pgs. 1, 8, 11, 15, 16 and 29.

11/16/2001 pgs. 4, 11, 18, 19, 23-25, 29-32, 34, 46 and 47.

12/19/2001 pgs. 13 and 30.

01/15/2002 pg. 51.

04/05/2002 pgs. 7, 8, 10, 11, 14, 47 and 52.

07/01/2002 pgs. 2 and 29.