IDT72V3664L10PFG - Integrated Device Technology

NOVEMBER 2003

IDT72V3654

IDT72V3664

IDT72V3674

3.3 VOLT CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2

4,096 x 36 x 2

8,192 x 36 x 2

IDT and the IDT logo are trademarks of Integrated Device Technology, Inc. The SyncFIFO is a trademark of Integrated Device Technology, Inc.

COMMERCIAL TEMPERATURE RANGE

FUNCTIONAL BLOCK DIAGRAM

FEATURES

••

•Memory storage capacity:

IDT72V3654 – 2,048 x 36 x 2

IDT72V3664 – 4,096 x 36 x 2

IDT72V3674 – 8,192 x 36 x 2

••

•Clock frequencies up to 100 MHz (6.5ns access time)

••

•Two independent clocked FIFOs buffering data in opposite

directions

••

•Select IDT Standard timing (using EFA, EFB, FFA, and FFB flags

functions) or First Word Fall Through Timing (using ORA, ORB,

IRA, and IRB flag functions)

••

•Programmable Almost-Empty and Almost-Full flags; each has five

default offsets (8, 16, 64, 256 and 1,024 )

••

•Serial or parallel programming of partial flags

••

•Port B bus sizing of 36 bits (long word), 18 bits (word) and 9 bits

(byte)

••

•Big- or Little-Endian format for word and byte bus sizes

••

•Retransmit Capability

••

•Master Reset clears data and configures FIFO, Partial Reset

clears data but retains configuration settings

••

•Mailbox bypass registers for each FIFO

••

•Free-running CLKA and CLKB may be asynchronous or coincident

(simultaneous reading and writing of data on a single clock edge

is permitted)

••

•Auto power down minimizes power dissipation

••

•Available in space saving 128-pin Thin Quad Flatpack (TQFP)

••

•Pin and functionally compatible version of the 5V operating

IDT723654/723664/723674

••

•Pin compatible to the lower density parts, IDT72V3624/72V3634/

72V3644

••

•Industrial temperature range (–40°°

°°

°C to +85°°

°°

°C) is available

Mail 1

Programmable Flag

Offset Registers

Input

RAM ARRAY

2,048 x 36

4,096 x 36

8,192 x 36

Write

Pointer

Read

Pointer

Status Flag

Logic

Input

Output

RAM ARRAY

2,048 x 36

4,096 x 36

8,192 x 36

Write

Pointer

Read

Pointer

Status Flag

Logic

CLKA

CSA

W/RA

ENA

MBA

Port-A

Control

Logic

FIFO1,

Mail1

Reset

Logic

MRS1

Mail 2

MBF2

CLKB

CSB

W/RB

ENB

MBB

SIZE

Port-B

Control

Logic

FIFO2,

Mail2

Reset

Logic

MRS2

MBF1

FIFO1

FIFO2

EFB/ORB

AEB

FFB/IRB

AFB

-B

FFA/IRA

AFA

FS2

FS0/SD

FS1/SEN

-A

EFA/ORA

AEA

4664 drw01

Output Bus-

Matching

Output

PRS2

PRS1

Timing

Mode FWFT

36 36

Input Bus-

Matching

FIFO1 and

FIFO2

Retransmit

Logic

RT1

RT2

RTM

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

PIN CONFIGURATION

TQFP (PK128-1, order code: PF)

TOP VIEW

W/RACLKB

4664 drw 02

ENA

CLKA

GND

A35

A34

A33

A32

Vcc

A31

A30

GND

A29

A28

A27

A26

A25

A24

A23

BE/FWFT

GND

A22

Vcc

A21

A20

A19

A18

GND

A17

A16

A15

A14

A13

Vcc

A12

GND

A11

A10

100

102

101

128

127

126

125

124

123

122

121

120

119

118

117

116

115

114

113

112

111

110

109

108

107

106

105

PRS2/RT2

Vcc

B35

B34

B33

B32

RTM

GND

B31

B30

B29

B28

B27

B26

Vcc

B25

B24

GND

B23

B22

B21

B20

B19

B18

GND

B17

B16

Vcc

B15

B14

B13

B12

GND

B11

B10

CSA

FFA/IRA

EFA/ORA

PRS1/RT1

Vcc

AFA

AEA

MBF2

MBA

MRS1

FS0/SD

GND

FS1/SEN

MRS2

MBB

MBF1

Vcc

AEB

AFB

EFB/ORB

FFB/IRB

GND

CSB

W/RB

ENB

GND

Vcc

GND

Vcc

104

103

INDEX

SIZE

FS2

DESCRIPTION

The IDT72V3654/72V3664/72V3674 are pin and functionally compat-

ible versions of the IDT723654/723664/723674, designed to run off a 3.3V

supply for exceptionally low-power consumption. These devices are mono-

lithic, high-speed, low-power, CMOS bidirectional synchronous (clocked)

FIFO memory which supports clock frequencies up to 100 MHz and has read

access times as fast as 6.5ns. Two independent 2,048/4,096/8,192 x 36 dual-

port SRAM FIFOs on board each chip buffer data in opposite directions. FIFO

data on Port B can be input and output in 36-bit, 18-bit, or 9-bit formats with a

choice of Big- or Little-Endian configurations.

These devices are a synchronous (clocked) FIFO, meaning each port

employs a synchronous interface. All data transfers through a port are gated

to the LOW-to-HIGH transition of a port clock by enable signals. The clocks for

each port are independent of one another and can be asynchronous or

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

coincident. The enables for each port are arranged to provide a simple

bidirectional interface between microprocessors and/or buses with synchro-

nous control.

Communication between each port may bypass the FIFOs via two mailbox

registers. The mailbox registers’ width matches the selected Port B bus width.

Each Mailbox register has a flag (MBF1 and MBF2) to signal when new mail

has been stored.

Two kinds of reset are available on these FIFOs: Master Reset and Partial

Reset. Master Reset initializes the read and write pointers to the first location

of the memory array, configures the FIFO for Big- or Little-Endian byte

arrangement and selects serial flag programming, parallel flag programming,

or one of five possible default flag offset settings, 8, 16, 64, 256 or 1,024. There

are two Master Reset pins, MRS1 and MRS2.

Partial Reset also sets the read and write pointers to the first location of the

memory. Unlike Master Reset, any settings existing prior to Partial Reset (i.e.,

programming method and partial flag default offsets) are retained. Partial Reset

is useful since it permits flushing of the FIFO memory without changing any

configuration settings. Each FIFO has its own, independent Partial Reset pin,

PRS1 and PRS2.

Both FIFO's have Retramsmit capability, when a Retransmit is performed

on a respective FIFO only the read pointer is reset to the first memory location.

A Retransmit is performed by using the Retransmit Mode, RTM pin in conjunction

with the Retransmit pins RT1 or RT2, for each respective FIFO. Note that the

two Retransmit pins RT1 and RT2 are muxed with the Partial Reset pins.

These devices have two modes of operation: In the IDT Standard mode,

the first word written to an empty FIFO is deposited into the memory array. A

read operation is required to access that word (along with all other words

residing in memory). In the First Word Fall Through mode (FWFT), the first

word written to an empty FIFO appears automatically on the outputs, no read

operation required (Nevertheless, accessing subsequent words does neces-

sitate a formal read request). The state of the BE/FWFT pin during Master

Reset determines the mode in use.

These devices have two modes of operation: In the IDT Standard mode,

the first word written to an empty FIFO is deposited into the memory array. A

read operation is required to access that word (along with all other words

residing in memory). In the First Word Fall Through mode (FWFT), the first long-

word (36-bit wide) written to an empty FIFO appears automatically on the

outputs, no read operation is required (Nevertheless, accessing subsequent

words does necessitate a formal read request). The state of the BE/FWFT pin

during FIFO operation determines the mode in use.

Each FIFO has a combined Empty/Output Ready Flag (EFA/ORA and

EFB/ORB) and a combined Full/Input Ready Flag (FFA/IRA and FFB/

IRB). The EF and FF functions are selected in the IDT Standard mode. EF

indicates whether or not the FIFO memory is empty. FF shows whether the

memory is full or not. The IR and OR functions are selected in the First Word

Fall Through mode. IR indicates whether or not the FIFO has available memory

locations. OR shows whether the FIFO has data available for reading or not.

It marks the presence of valid data on the outputs.

Each FIFO has a programmable Almost-Empty flag (AEA and AEB)

and a programmable Almost-Full flag (AFA and AFB). AEA and AEB

indicate when a selected number of words remain in the FIFO memory. AFA

and AFB indicate when the FIFO contains more than a selected number of

words.

FFA/IRA, FFB/IRB, AFA and AFB are two-stage synchronized to the

port clock that writes data into its array. EFA/ORA, EFB/ORB, AEA and

AEB are two-stage synchronized to the port clock that reads data from its array.

Programmable offsets for AEA, AEB, AFA and AFB are loaded in parallel

using Port A or in serial via the SD input. Five default offset settings are also

provided. The AEA and AEB threshold can be set at 8, 16, 64, 256 or 1,024

locations from the empty boundary and the AFA and AFB threshold can be

set at 8, 16, 64, 256 or 1,024 locations from the full boundary. All these choices

are made using the FS0, FS1 and FS2 inputs during Master Reset.

Interspersed Parity can also be selected during a Master Reset of the

FIFO. If Interspersed Parity is selected then during parallel programming of the

flag offset values, the device will ignore data line A8. If Non-Interspersed Parity

is selected then data line A8 will become a valid bit.

Two or more devices may be used in parallel to create wider data paths.

If, at any time, the FIFO is not actively performing a function, the chip will

automatically power down. During the power down state, supply current

consumption (ICC) is at a minimum. Initiating any operation (by activating control

inputs) will immediately take the device out of the power down state.

The IDT72V3654/72V3664/72V3674 are characterized for operation from

0°C to 70°C. Industrial temperature range (-40°C to +85°C) is available. They

are fabricated using IDT’s high speed, submicron CMOS technology.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

PIN DESCRIPTIONS

Symbol Name I/O Description

A0-A35 Port A Data I/O 36-bit bidirectional data port for side A.

AEA Port A Almost- O Programmable Almost-Empty flag synchronized to CLKA. It is LOW when the number of words in

Empty Flag FIFO2 is less than or equal to the value in the Almost-Empty A Offset register, X2.

AEB Port B Almost- O Programmable Almost-Empty flag synchronized to CLKB. It is LOW when the number of words in

Empty Flag FIFO1 is less than or equal to the value in the Almost-Empty B Offset register, X1.

AFA Port A Almost- O Programmable Almost-Full flag synchronized to CLKA. It is LOW when the number of empty

Full Flag locations in FIFO1 is less than or equal to the value in the Almost-Full A Offset register, Y1.

AFB Port B Almost- O Programmable Almost-Full flag synchronized to CLKB. It is LOW when the number of empty

Full Flag locations in FIFO2 is less than or equal to the value in the Almost-Full B Offset register, Y2.

B0-B35 Port A Data I/O 36-bit bidirectional data port for side B.

BE/FWFT Big-Endian/ I This is a dual purpose pin. During Master Reset, a HIGH on BE will select Big Endian operation.

First Word In this case, depending on the bus size, the most significant byte or word on Port A is read from

Fall Through Port B first (A-to-B data flow) or written to Port B first (B-to-A data flow). A LOW on BE will select

Select Little-Endian operation. In this case, the least significant byte or word on Port A is read from Port B

first (for A-to-B data flow) or written to Port B first (B-to-A data

flow). After Master Reset, this pin

selects the timing mode. A HIGH on FWFT

selects IDT Standard mode, a LOW selects First Word

Fall Through mode. Once the timing mode has been selected, the level on FWFT must be static

throughout device operation.

BM(1) Bus-Match Select I

A HIGH on this pin enables either byte or word bus width on Port B, depending

on the state of

(Port B) SIZE. A LOW selects long word operation. BM works with SIZE and BE to select the bus size and

endian arrangement for Port B. The level of BM must be static throughout device operation.

CLKA Port A Clock I CLKA is a continuous clock that synchronizes all data transfers through Port A and can be

asynchronous or coincident to CLKB. FFA/IRA, EFA/ORA, AFA, and AEA are all synchronized

to the LOW-to-HIGH transition of CLKA.

CLKB Port B Clock I CLKB is a continuous clock that synchronizes all data transfers through Port B and can be

asynchronous or coincident to CLKA. FFB/IRB, EFB/ORB, AFB, and AEB are synchronized to

the LOW-to-HIGH transition of CLKB.

CSA Port A Chip Select I CSA must be LOW to enable to LOW-to-HIGH transition of CLKA to read or write on Port A.

The A0-A35 outputs are in the high-impedance state when CSA is HIGH.

CSB Port B Chip Select I CSB must be LOW to enable a LOW-to-HIGH transition of CLKB to read or write data on Port B.

The B0-B35 outputs are in the high-impedance state when CSB is HIGH.

EFA/ORA Port A Empty/ O This is a dual function pin. In the IDT Standard mode, the EFA function is selected. EFA

Output Ready Flag indicates whether or not the FIFO2 memory is empty. In the FWFT mode, the ORA function is

selected. ORA indicates the presence of valid data on A0-A35 outputs, available for reading.

EFA/ORA is synchronized to the LOW-to-HIGH transition of CLKA.

EFB/ORB Port B Empty/ O This is a dual function pin. In the IDT Standard mode, the EFB function is selected. EFB indicates

Output Ready Flag whether or not the FIFO1 memory is empty. In the FWFT mode, the ORB function is selected. ORB

indicates the presence of valid data on the B0-B35 outputs, available for reading. EFB/ORB is

synchronized to the LOW-to-HIGH transition of CLKB.

ENA Port A Enable I ENA must be HIGH to enable a LOW-to-HIGH transition of CLKA to read or write data on Port A.

ENB Port B Enable I ENB must be HIGH to enable a LOW-to-HIGH transition of CLKB to read or write data on Port B.

FFA/IRA Port A Full/ O This is a dual function pin. In the IDT Standard mode, the FFA function is selected. FFA indicates

Input Ready Flag whether or not the FIFO1 memory is full. In the FWFT mode, the IRA function is selected. IRA

indicates whether or not there is space available for writing to the FIFO1 memory. FFA/IRA is

synchronized to the LOW-to-HIGH transition of CLKA.

FFB/IRB Port B Full/ O This is a dual function pin. In the IDT Standard mode, the FFB function is selected. FFB indicates

Input Ready Flag whether or not the FIFO2 memory is full. In the

FWFT mode, the IRB function is selected. IRB

indicates whether or not there is space available for writing to the FIFO2 memory. FFB/IRB is

synchronized to the LOW-to-HIGH transition of CLKB.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Symbol Name I/O Description

FS0/SD Flag Offset Select 0/ I FS1/SEN and FS0/SD are dual-purpose inputs used for flag offset register programming. During

Serial Data Master Reset, FS1/SEN and FS0/SD, together with FS2, select the flag offset programming method

Three offset register programming methods are available: automatically load one of five preset values

(8, 16, 64, 256 or 1,024), parallel load from Port A, and serial load.

FS1/SEN Flag Offset Select 1/ I

Serial Enable, When serial load is selected for flag offset register programming, FS1/SEN is used as an enable

synchronous to the LOW-to-HIGH transition of CLKA. When FS1/SEN is LOW, a rising edge on CLKA

FS2(1) Flag Offset Select 2 I load the bit present on FS0/SD into the X and Y registers. The number of bit writes required to program

the offset registers is 44 for the IDT72V3654, 48 for the IDT72V3664, and 52 for the IDT72V3674.

The first bit write stores the Y-register (Y1) MSB and the last bit write stores the X-register (X2) LSB.

MB A Port A Mailbox I A HIGH level on MBA chooses a mailbox register for a Port A read or write operation. When

Select the A0-A35 outputs are active, a HIGH level on MBA selects data from the mail2 register for output

and a LOW level selects FIFO2 output register data for output.

MB B Port B Mailbox I A HIGH level on MBB chooses a mailbox register for a Port B read or write operation. When the

Select B0-B35 outputs are active, a HIGH level on MBB selects data from the mail1 register for output and

a LOW level selects FIFO1 output register data for output.

MBF1 Mail1 Register O MBF1 is set LOW by a LOW-to-HIGH transition of CLKA that writes data to the mail1 register.

Flag Writes to the mail1 register are inhibited while MBF1 is LOW. MBF1 is set HIGH by a LOW-to-HIGH

transition of CLKB when a Port B read is selected and MBB is HIGH. MBF1 is set HIGH following either

a Master or Partial Reset of FIFO1.

MBF2 Mail2 Register O MBF2 is set LOW by a LOW-to-HIGH transition of CLKB that writes data to the mail2 register. Writes

Flag to the mail2 register are inhibited while MBF2 is LOW. MBF2 is set HIGH by a LOW-to-HIGH

transition of CLKA when a Port A read is selected and MBA is HIGH. MBF2 is set HIGH following

either a Master or Partial Reset of FIFO2.

MRS1 FIFO1 Master I A LOW on this pin initializes the FIFO1 read and write pointers to the first location

of memory and

sets the

Reset

Port B output register to all zeroes. A LOW-to-HIGH transition

on MRS1 selects the programming

method (serial or parallel) and one of five programmable flag default offsets for FIFO1 and FIFO2. It

also configures Port B for bus size and endian arrangement. Four LOW-to-HIGH transitions of CLKA

and four LOW-to-HIGH transitions of CLKB must occur while MRS1 is LOW.

MRS2 FIFO2 Master I A LOW on this pin initializes the FIFO2 read and write pointers to the first location of memory and sets

Reset the Port A output register to all zeroes. A LOW-to-HIGH transition on MRS2, toggled simultaneously with

MRS1, selects the programming method (serial or parallel) and one of the programmable flag default

offsets for

FIFO2. Four LOW-to-HIGH transitions of CLKA and four LOW-to-HIGH transitions

of CLKB

must occur while MRS2 is LOW.

PRS1/ Partial Reset/ I This pin is muxed for both Partial Reset and Retransmit operations, it is used in conjunction with the RTM

RT1 Retransmit FIFO1 pin. If RTM is in a LOW condition, a LOW on this pin performs a Partial Reset on FIFO1 and initializes

the FIFO1 read and write pointers to the first location of memory and sets the Port B output register to

all zeroes. During Partial Reset, the currently selected bus size, endian arrangement, programming

method (serial or parallel), and programmable flag settings are all retained. If RTM is HIGH, a LOW on

this pin performs a Retransmit and initializes the FIFO1 read pointer only to the first memory location.

PRS2/ Partial Reset/ I This pin is muxed for both Partial Reset and Retransmit operations, it is used in conjunction with the RTM

RT2 Retransmit FIFO2 pin. If RTM is in a LOW condition, a LOW on this pin performs a Partial Reset on FIFO2 and initializes

the FIFO2 read and write selected bus size, endian arrangement, programming method (serial or

parallel), and programmable flag settings are all retained. If RTM is HIGH, a LOW on this pin performs

a Retransmit and initializes the FIFO2 read pointer only to the first memory location.

RTM Retransmit Mode I This pin is used in conjunction with the RT1 and RT2 pins. When RTM is HIGH a Retransmit is performed

on FIFO1 or FIFO2 respectively.

SIZE(1) Bus Size Select I A HIGH on this pin when BM is HIGH selects byte bus (9-bit) size on Port B. A LOW on this pin when

BM is HIGH selects word (18-bit) bus size. SIZE works with BM and BE to select the bus size and endian

arrangement for Port B. The level of SIZE must be static throughout device operation

PIN DESCRIPTIONS (CONTINUED)

NOTE:

1. FS2, BM and SIZE inputs are not TTL compatible. These inputs should be tied to GND or VCC.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Symbol Name I/O Description

W/RA Port-A Write/ I A HIGH selects a write operation and a LOW selects a read operation on Port A for a LOW-to-HIGH

Read Select transition of CLKA. The A0-A35 outputs are in the HIGH impedance state when W/RA is HIGH.

W/RB Port-B Write/ I A LOW selects a write operation and a HIGH selects a read operation on Port B for a LOW-to-HIGH

Read Select transition of CLKB. The B0-B35 outputs are in the HIGH impedance state when W/RB is LOW.

PIN DESCRIPTIONS (CONTINUED)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

ELECTRICAL CHARACTERISTICS OVER RECOMMENDED OPERATING FREE-

AIR TEMPERATURE RANGE (Unless otherwise noted)

Symbol Rating Commercial Unit

VCC Supply Voltage Range –0.5 to +4.6 V

VI(2) Input Voltage Range –0.5 to VCC+0.5 V

VO(2) Output Voltage Range –0.5 to VCC+0.5 V

IIK Input Clamp Current (VI < 0 or VI > VCC) ±20 mA

IOK Output Clamp Current (VO = < 0 or VO > VCC) ±50 mA

IOUT Continuous Output Current (VO = 0 to VCC) ±50 mA

ICC Continuous Current Through VCC o r GN D ±400 mA

TSTG Storage Temperature Range –65 to 150 °C

NOTES:

1. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these

or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect

device reliability.

2. The input and output voltage ratings may be exceeded provided the input and output current ratings are observed.

ABSOLUTE MAXIMUM RATINGS OVER OPERATING FREE-AIR

TEMPERATURE RANGE (Unless otherwise noted)(1)

RECOMMENDED OPERATING CONDITIONS

NOTE:

1. For 10ns speed grade: Vcc = 3.3V ± 0.15V, JEDEC JESD8-A compliant

Symbol Parameter Min. Typ. Max. Unit

VCC(1) Supply Voltage for 10ns 3.15 3.3 3.45 V

VCC Supply Voltage for 15ns 3.0 3.3 3.6 V

VIH High-Level Input Voltage 2 — VCC+0.5 V

VIL Low-Level Input Voltage — — 0.8 V

IOH High-Level Output Current — — –4 mA

IOL Low-Level Output Current — — 8 mA

TAOperating Temperature 0 — 70 °C

NOTES:

1. All typical values are at VCC = 3.3V, TA = 25°C.

2. Commercial-10ns speed grade only: Vcc = 3.3V ± 0.15V, TA = 0° to +70°; JEDEC JESD8-A compliant.

3. For additional ICC information, see Figure 1, Typical Characteristics: Supply Current (ICC) vs. Clock Frequency (fS).

4. Characterized values, not currently tested.

IDT72V3654

IDT72V3664

IDT72V3674

Commercial

tCLK = 10, 15 ns(2)

Symbol Parameter Test Conditions Min. Typ.(1) Max. Unit

VOH Output Logic "1" Voltage VCC = 3.0V, IOH = –4 mA 2.4 — — V

VOL Output Logic "0" Voltage VCC = 3.0V, IOL = 8 mA — — 0.5 V

ILI Input Leakage Current (Any Input) VCC = 3.6V, VI = VCC or 0 — — ±10 µA

ILO Output Leakage Current VCC = 3.6V, VO = VCC or 0 — — ±10 µA

ICC2(3) Standby Current (with CLKA & CLKB running) VCC = 3.6V, VI = VCC –0.2V or 0V — — 5 mA

ICC3(3) Standby Current (no clocks running) VCC = 3.6V, VI = VCC –0.2V or 0V — — 1 mA

CIN(4) Input Capacitance VI = 0, f = 1 MHz — 4 — pF

COUT(4) Output Capacitance VO = 0, f = 1 MHZ — 8 — pF

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

DETERMINING ACTIVE CURRENT CONSUMPTION AND POWER DISSIPATION

The ICC(f) current for the graph in Figure 1 was taken while simultaneously reading and writing a FIFO on the IDT72V3654/72V3664/72V3674 with CLKA

and CLKB set to fS. All data inputs and data outputs change state during each clock cycle to consume the highest supply current. Data outputs were disconnected

to normalize the graph to a zero capacitance load. Once the capacitance load per data-output channel and the number of these device's inputs driven by TTL

HIGH levels are known, the power dissipation can be calculated with the equation below.

CALCULATING POWER DISSIPATION

With ICC(f) taken from Figure 1, the maximum power dissipation (PT) of these FIFOs may be calculated by:

PT = VCC x ICC(f) + Σ(CL x VCC2 x fo)

where:

N = number of used outputs (36-bit (long word), 18-bit (word) or 9-bit (byte) bus size)

CL= output capacitance load

fo= switching frequency of an output

Figure 1. Typical Characteristics: Supply Current (ICC) vs. Clock Frequency (fS)

010203040506070

 Clock Frequency  MHz

CC(f)

Supply Current

data

= 1/2

= 25°C

= 0 pF

4664 drw03

100

80 90 100

CC =

3.3V

CC =

3.6V

CC =

3.0V

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

TIMING REQUIREMENTS OVER RECOMMENDED RANGES OF SUPPLY

VOLTAGE AND OPERATING FREE-AIR TEMPERATURE

IDT72V3654L10(1) IDT72V3654L15

IDT72V3664L10(1) IDT72V3664L15

IDT72V3674L10(1) IDT72V3674L15

Symbol Parameter Min. Max. Min. Max. Unit

fSClock Frequency, CLKA or CLKB — 100 — 66.7 MH z

tCLK Clock Cycle Time, CLKA or CLKB 10 — 1 5 — n s

tCLKH Pulse Duration, CLKA or CLKB HIGH 4.5 — 6 — n s

tCLKL Pulse Duration, CLKA and CLKB LOW 4.5 — 6 — ns

tDS Setup Time, A0-A35 before CLKA↑ and B0-B35 before CLKB↑3—4—ns

tENS1 Setup Time, CSA and W/RA before CLKA↑; CSB and 4 — 4.5 — n s

W/RB before CLKB↑

tENS2 Setup Time, ENA, and MBA before CLKA↑; ENB, and 3 — 4.5 — ns

MBB before CLKB↑

tRSTS Setup Time, MRS1, MRS2, PRS1, or PRS2 LOW before 5 — 5 — n s

CLKA↑ or CLKB↑(2)

tFSS Setup Time, FS0, FS1, FS2 before MRS1 and MRS2 HIGH 7.5 — 7.5 — ns

tBES Setup Time, BE/FWFT before MRS1 and MRS2 HIGH 7.5 — 7.5 — ns

tSDS Setup Time, FS0/SD before CLKA↑3—4—ns

tSENS Setup Time, FS1/SEN before CLKA↑3—4—ns

tFWS Setup Time, BE/FWFT before CLKA↑0—0—ns

tRTMS Setup Time, RTM before RT1; RTM before RT2 5—5—ns

tDH Hold Time, A0-A35 after CLKA↑ and B0-B35 after CLKB↑0.5 — 1 — ns

tENH Hold Time, CSA, W/RA, ENA, and MBA after CLKA↑; CSB, 0.5 — 1 — ns

W/RB, ENB, and MBB after CLKB↑

tRSTH Hold Time, MRS1, MRS2, PRS1 or PRS2 LOW after CLKA↑4—4—ns

or CLKB↑(2)

tFSH Hold Time, FS0, FS1, FS2 after MRS1 and MRS2 HIGH 2 — 2 — n s

tBEH Hold Time, BE/FWFT after MRS1 and MRS2 HIGH 2 — 2 — n s

tSDH Hold Time, FS0/SD after CLKA↑0.5 — 1 — ns

tSENH Hold Time, FS1/SEN HIGH after CLKA↑0.5 — 1 — ns

tSPH Hold Time, FS1/SEN HIGH after MRS1 and MRS2 HIGH 2 — 2 — n s

tRTMH Hold Time, RTM after RT1; RTM after RT2 5—5—ns

tSKEW1(3) Skew Time between CLKA↑ and CLKB↑ for EFA/ORA, 5 — 7.5 — ns

EFB/ORB, FFA/IRA, and FFB/IRB

tSKEW2(3,4) Skew Time between CLKA↑ and CLKB↑ for AEA, AEB, AFA,12—12—ns

and AFB

NOTES:

1 . For 10ns speed grade:

Vcc = 3.3V ± 0.15V; TA = 0° to +70°.

2. Requirement to count the clock edge as one of at least four needed to reset a FIFO.

3. Skew time is not a timing constraint for proper device operation and is only included to illustrate the timing relationship between CLKA cycle and CLKB cycle.

4. Design simulated, not tested.

(For 10ns speed grade only: Vcc = 3.3V ± 0.15V; TA = 0° C to +70° C; JEDEC JESD8-A compliant)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

SWITCHING CHARACTERISTICS OVER RECOMMENDED RANGES OF SUPPLY

VOLTAGE AND OPERATING FREE-AIR TEMPERATURE, CL = 30pF

IDT72V3654L10(1) IDT72V3654L15

IDT72V3664L10(1) IDT72V3664L15

IDT72V3674L10(1) IDT72V3674L15

Symbol Parameter Min. Max. Min. Max. Unit

tAAccess Time, CLKA↑ to A0-A35 and CLKB↑ to B0-B35 2 6.5 2 10 ns

tWFF Propagation Delay Time, CLKA↑ to FFA/IRA and CLKB↑2 6.5 2 8 ns

to FFB/IRB

tREF Propagation Delay Time, CLKA↑ to EFA/ORA and CLKB↑1 6.5 1 8 ns

to EFB/ORB

tPAE Propagation Delay Time, CLKA↑ to AEA and CLKB↑ to 1 6.5 1 8 ns

AEB

tPAF Propagation Delay Time, CLKA↑ to AFA and CLKB↑ to 1 6.5 1 8 ns

AFB

tPMF Propagation Delay Time, CLKA↑ to MBF1 LOW or MBF2 0 6.5 0 8 ns

HIGH and CLKB↑ to MBF2 LOW or MBF1 HIGH

tPMR Propagation Delay Time, CLKA↑ to B0-B35(2) and CLKB↑38210ns

to A0-A35(3)

tMDV Propagation Delay Time, MBA to A0-A35 valid and MBB to 3 6.5 2 10 n s

B0-B35 valid

tRSF Propagation Delay Time, MRS1 or PRS1 LOW to AEB 110115ns

LOW, AFA HIGH, and MBF1 HIGH and MRS2 or PRS2

LOW to AEA LOW, AFB HIGH, and MBF2 HIGH

tEN Enable Time, CSA or W/RA LOW to A0-A35 Active and 2 6 2 10 ns

CSB LOW and W/RB HIGH to B0-B35 Active

tDIS Disable Time, CSA or W/RA HIGH to A0-A35 at high 1 6 1 8 n s

impedance and CSB HIGH or W/RB LOW to B0-B35 at

high impedance

NOTES:

1 . For 10ns speed grade:

Vcc = 3.3V ± 0.15V; TA = 0° to +70°.

2. Writing data to the mail1 register when the B0-B35 outputs are active and MBB is HIGH.

3. Writing data to the mail2 register when the A0-A35 outputs are active and MBA is HIGH.

(For 10ns speed grade only: Vcc = 3.3V ± 0.15V; TA = 0ο C to +70ο C; JEDEC JESD8-A compliant)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

SIGNAL DESCRIPTION

MASTER RESET (MRS1, MRS2)

After power up, a Master Reset operation must be performed by providing

a LOW pulse to MRS1 and MRS2 simultaneously. Afterwards, each of the

two FIFO memories of the IDT72V3654/72V3664/72V3674 undergoes a

complete reset by taking its associated Master Reset (MRS1, MRS2) input

LOW for at least four Port A Clock (CLKA) and four Port B Clock (CLKB) LOW-

to-HIGH transitions. The Master Reset inputs can switch asynchronously to

the clocks. A Master Reset initializes the associated write and read pointers to

the first location of the memory and forces the Full/Input Ready flag (FFA/IRA,

FFB/IRB) LOW, the Empty/Output Ready flag (EFA/ORA, EFB/ORB) LOW,

the Almost-Empty flag (AEA, AEB) LOW and forces the Almost-Full flag

(AFA, AFB) HIGH. A Master Reset also forces the associated Mailbox Flag

(MBF1, MFB2) of the parallel mailbox register HIGH. After a Master Reset,

the FIFO's Full/Input Ready flag is set HIGH after two write clock cycles. Then

the FIFO is ready to be written to.

A LOW-to-HIGH transition on the FIFO1 Master Reset (MRS1) input

latches the values of the Big-Endian (BE) input for determining the order by

which bytes are transferred through Port B. It also latches the values of the

Flag Select (FS0, FS1 and FS2) inputs for choosing the Almost-Full and Almost-

Empty offset programming method.

A LOW-to-HIGH transition on the FIFO2 Master Reset (MRS2) clears

the Flag Offset Registers of FIFO2 (X2, Y2). A LOW-to-HIGH transition on the

FIFO2 Master Reset (MRS2) together with the FIFO1 Master Reset (MRS1)

input latches the value of the Big-Endian (BE) input for Port B and also latches

the values of the Flag Select (FS0, FS1 and FS2) inputs for choosing the Almost-

Full and Almost-Empty offset programming method. (For details see Table 1,

Flag Programming, and the Programming the Almost-Empty and Almost-Full

Flags section). The relevant FIFO Master Reset timing diagram can be found

in Figure 3.

PARTIAL RESET (PRS1, PRS2)

Each of the two FIFO memories of these devices undergoes a limited reset

by taking its associated Partial Reset (PRS1, PRS2) input LOW for at least

four Port A Clock (CLKA) and four Port B Clock (CLKB) LOW-to-HIGH

transitions. The Partial Reset inputs can switch asynchronously to the clocks.

A Partial Reset initializes the internal read and write pointers and forces the

Full/Input Ready flag (FFA/IRA, FFB/IRB) LOW, the Empty/Output Ready

flag (EFA/ORA, EFB/ORB) LOW, the Almost-Empty flag (AEA, AEB)

LOW, and the Almost-Full flag (AFA, AFB) HIGH. A Partial Reset also forces

the Mailbox Flag (MBF1, MBF2) of the parallel mailbox register HIGH. After

a Partial Reset, the FIFO’s Full/Input Ready flag is set HIGH after two write

clock cycles. Then the FIFO is ready to be written to.

Whatever flag offsets, programming method (parallel or serial), and timing

mode (FWFT or IDT Standard mode) are currently selected at the time a Partial

Reset is initiated, those settings will be remain unchanged upon completion of

the reset operation. A Partial Reset may be useful in the case where

reprogramming a FIFO following a Master Reset would be inconvenient. See

Figure 4 for the Partial Reset timing diagram.

RETRANSMIT (RT1, RT2)

The FIFO1 memory of these devices undergoes a Retransmit by taking its

associated Retransmit (RT1) input LOW for at least four Port A Clock (CLKA)

and four Port B Clock (CLKB) LOW-to-HIGH transitions. The Retransmit

initializes the read pointer of FIFO1 to the first memory location.

The FIFO2 memory undergoes a Retransmit by taking its associated

Retransmit (RT2) input LOW for at least four Port A Clock (CLKA) and four Port

C Clock (CLKC) LOW-to-HIGH transitions. The Retransmit initializes the read

pointer of FIFO2 to the first memory location.

The RTM pin must be HIGH during the time of Retranmit. Note that the

RT1input is muxed with the PRS1 input, the state of the RTM pin determining

whether this pin performs a Retransmit or Partial Reset. Also, the RT2input is

muxed with the PRS2 input, the state of the RTM pin determining whether this

pin performs a Retransmit or Partial Reset.

BIG-ENDIAN/FIRST WORD FALL THROUGH (BE/FWFT)

— ENDIAN SELECTION

This is a dual purpose pin. At the time of Master Reset, the BE select function

is active, permitting a choice of Big or Little-Endian byte arrangement for data

written to or read from Port B. This selection determines the order by which

bytes (or words) of data are transferred through this port. For the following

illustrations, assume that a byte (or word) bus size has been selected for Port

B. (Note that when Port B is configured for a long word size, the Big-Endian

function has no application and the BE input is a “don’t care”1.)

A HIGH on the BE/FWFT input when the Master Reset (MRS1, MRS2)

inputs go from LOW to HIGH will select a Big-Endian arrangement. When data

is moving in the direction from Port A to Port B, the most significant byte (word)

of the long word written to Port A will be read from Port B first; the least significant

byte (word) of the long word written to Port A will be read from Port B last. When

data is moving in the direction from Port B to Port A, the byte (word) written

to Port B first will be read from Port A as the most significant byte (word) of the

long word; the byte (word) written to Port B last will be read from Port A as

the least significant byte (word) of the long word.

A LOW on the BE/FWFT input when the Master Reset (MRS1, MRS2)

inputs go from LOW to HIGH will select a Little-Endian arrangement. When data

is moving in the direction from Port A to Port B, the least significant byte (word)

of the long word written to Port A will be read from Port B first; the most significant

byte (word) of the long word written to Port A will be read from Port B last. When

data is moving in the direction from Port B to Port A, the byte (word) written

to Port B first will be read from Port A as the least significant byte (word) of the

long word; the byte (word) written to Port B last will be read from Port A as

the most significant byte (word) of the long word. Refer to Figure 2 for an

illustration of the BE function. See Figure 3 (Master Reset) for the Endian select

timing diagram.

— TIMING MODE SELECTION

After Master Reset, the FWFT select function is active, permitting a choice

between two possible timing modes: IDT Standard mode or First Word Fall

Through (FWFT) mode. Once the Master Reset (MRS1, MRS2) input is

HIGH, a HIGH on the BE/FWFT input during the next LOW-to-HIGH

transition of CLKA (for FIFO1) and CLKB (for FIFO2) will select IDT Standard

mode. This mode uses the Empty Flag function (EFA, EFB) to indicate

whether or not there are any words present in the FIFO memory. It uses the

Full Flag function (FFA, FFB) to indicate whether or not the FIFO memory

has any free space for writing. In IDT Standard mode, every word read from

the FIFO, including the first, must be requested using a formal read operation.

NOTE:

1 . Either a HIGH or LOW can be applied to a "don't care" input with no change to the logical operation of the FIFO. Nevertheless, inputs that are temporarily "don't care" (along with

unused inputs) must not be left open, rather they must be either HIGH or LOW.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Once the Master Reset (MRS1, MRS2) input is HIGH, a LOW on the BE/

FWFT input during the next LOW-to-HIGH transition of CLKA (for FIFO1) and

CLKB (for FIFO2) will select FWFT mode. This mode uses the Output Ready

function (ORA, ORB) to indicate whether or not there is valid data at the data

outputs (A0-A35 or B0-B35). It also uses the Input Ready function (IRA, IRB)

to indicate whether or not the FIFO memory has any free space for writing.

In the FWFT mode, the first word written to an empty FIFO goes directly to data

outputs, no read request necessary. Subsequent words must be accessed

by performing a formal read operation.

Following Master Reset, the level applied to the BE/FWFT input to choose

the desired timing mode must remain static throughout FIFO operation. Refer

to Figure 3 (Master Reset) for a First Word Fall Through select timing diagram.

PROGRAMMING THE ALMOST-EMPTY AND ALMOST-FULL FLAGS

Four registers in the IDT72V3654/72V3664/72V3674 are used to hold the

offset values for the Almost-Empty and Almost-Full flags. The Port B Almost-

Empty flag (AEB) Offset register is labeled X1 and the Port A Almost-Empty

flag (AEA) Offset register is labeled X2. The Port A Almost-Full flag (AFA)

Offset register is labeled Y1 and the Port B Almost-Full flag (AFB) Offset register

is labeled Y2. The index of each register name corresponds to its FIFO number.

The offset registers can be loaded with preset values during the reset of a FIFO,

programmed in parallel using the FIFO’s Port A data inputs, or programmed

in serial using the Serial Data (SD) input (see Table 1).

FS0/SD, FS1/SEN and FS2 function the same way in both IDT Standard

and FWFT modes.

— PRESET VALUES

To load a FIFO’s Almost-Empty flag and Almost-Full flag Offset registers with

one of the five preset values listed in Table 1, the flag select inputs must be HIGH

or LOW during a master reset. For example, to load the preset value of 64 into

X1 and Y1, FS0, FS1 and FS2 must be HIGH when FlFO1 reset (MRS1) returns

HIGH. Flag-offset registers associated with FIFO2 are loaded with one of the

preset values in the same way with FIFO2 Master Reset (MRS2), toggled

simultaneously with FIFO1 Master Reset (MRS1). For relevant preset value

loading timing diagram, see Figure 3.

PARALLEL LOAD FROM PORT A

To program the X1, X2, Y1, and Y2 registers from Port A, perform a Master

Reset on both FlFOs simultaneously with FS2 HIGH or LOW, FS0 and FS1

LOW during the LOW-to-HIGH transition of MRS1 and MRS2. The state of FS2

at this point of reset will determine whether the parallel programming method

has Interspersed Parity or Non-Interspersed Parity. Refer to Table 1 for Flag

Programming Flag Offset setup . It is important to note that once parallel

programming has been selected during a Master Reset by holding both FS0

& FS1 LOW, these inputs must remain LOW during all subsequent FIFO

operation. They can only be toggled HIGH when future Master Resets are

performed and other programming methods are desired.

After this reset is complete, the first four writes to FIFO1 do not store data

in RAM but load the Offset registers in the order Y1, X1, Y2, X2. For Non-

Interspersed Parity mode the Port A data inputs used by the Offset registers are

(A10-A0), (A11-A0), or (A12-A0) for the IDT72V3654, IDT72V3664, or

IDT72V3674, respectively. For Interspersed Parity mode the Port A data inputs

used by the Offset registers are (A11-A9, A7-A0), (A12-A9, A7-A0), or (A13-

A9, A7-A0) for the IDT72V3654, IDT72V3664, or IDT72V3674, respectively.

The highest numbered input is used as the most significant bit of the binary

number in each case. Valid programming values for the registers range from

1 to 2,044 for the IDT72V3654; 1 to 4,092 for the IDT72V3664; and 1 to 8,188

for the IDT72V3674. After all the offset registers are programmed from Port A,

NOTES:

1. X1 register holds the offset for AEB; Y1 register holds the offset for AFA.

2. X2 register holds the offset for AEA; Y2 register holds the offset for AFB.

3. When this method of parallel programming is selected, Port A will assume Non-Interspersed Parity.

4. When IP Mode is selected, only parallel programming of the offset values via Port A, can be performed and Port A will assume Interspersed Parity.

5. IF parallel programming is selected during a Master Reset, then FS0 & FS1 must remain LOW during FIFO operation.

FS2 FS1/SEN FS0/SD MRS1 MRS2 X1 AND Y1 REGlSTERS(1) X2 AND Y2 REGlSTERS(2)

HHH↑X64 X

HHHX↑X64

HHL↑X16 X

HHLX↑X16

HLH↑X8 X

HLHX↑X8

LHH↑X 256 X

LHHX↑X 256

LLH↑X 1,024 X

LLHX↑X 1,024

LHL↑↑ Serial programming via SD Serial programming via SD

HLL↑↑ Parallel programming via Port A(3, 5) Parallel programming via Port A(3, 5)

LLL↑↑ IP Mode(4, 5) IP Mode(4, 5)

TABLE 1 — FLAG PROGRAMMING

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

offset values, the device will ignore data line A8. If Non-Interspersed Parity is

selected then data line A8 will become a valid bit. If Interspersed Parity is selected

serial programming of the offset values is not permitted, only parallel program-

ming can be done.

— SERIAL LOAD

To program the X1, X2, Y1, and Y2 registers serially, initiate a Master Reset

with FS2 LOW, FS0/SD LOW and FS1/SEN HIGH during the LOW-to-HIGH

transition of MRS1 and MRS2. After this reset is complete, the X and Y register

values are loaded bit-wise through the FS0/SD input on each LOW-to-HIGH

transition of CLKA that the FS1/SEN input is LOW. There are 44-, 48-, or 52-

bit writes needed to complete the programming for the IDT72V3654, IDT72V3664,

or IDT72V3674, respectively. The four registers are written in the order Y1,

TABLE 3 — PORT B ENABLE FUNCTION TABLE

the Port B Full/Input Ready flag (FFB/IRB) is set HIGH, and both FIFOs begin

normal operation. Refer to Figure 5 for a timing diagram illustration of parallel

programming of the flag offset values.

INTERSPERSED PARITY

Interspersed Parity is selected during a Master Reset of the FIFO. Refer to

Table 1 for the set-up configuration of Interspersed Parity. The Interspersed

Parity function allows the user to select the location of the parity bits in the word

loaded into the parallel port (A0-An) during programming of the flag offset values.

If Interspersed Parity is selected then during parallel programming of the flag

CSA W/RA ENA MB A CLKA Data A (A0-A35) I/O Port Function

H X X X X High-Impedance None

L H L X X Input None

LHH L ↑Input FIFO1 write

LHH H ↑Input Mail1 write

L L L L X Output None

LLH L ↑Output FIFO2 read

L L L H X Output None

LLHH ↑Output Mail2 read (set MBF2 HIGH)

TABLE 2 — PORT A ENABLE FUNCTION TABLE

CSB W/RB ENB MBB CLKB Data B (B0-B35) I/O Port Function

H X X X X High-Impedance None

L L L X X Input None

LLH L ↑Input FIFO2 write

LLHH ↑Input Mail2 write

L H L L X Output None

LHH L ↑Output FIFO1 read

L H L H X Output None

LHH H ↑Output Mail1 read (set MBF1 HIGH)

X1, Y2, and finally, X2. The first-bit write stores the most significant bit of the Y1

(IDT72V3664), or 1 to 8,188 (IDT72V3674).

When the option to program the offset registers serially is chosen, the Port

A Full/Input Ready (FFA/IRA) flag remains LOW until all register bits are written.

FFA/IRA is set HIGH by the LOW-to-HIGH transition of CLKA after the last bit

is loaded to allow normal FIFO1 operation. The Port B Full/Input Ready (FFB/

IRB) flag also remains LOW throughout the serial programming process, until

all register bits are written. FFB/IRB is set HIGH by the LOW-to-HIGH transition

of CLKB after the last bit is loaded to allow normal FIFO2 operation. See Figure 6

for Serial Programming of the Almost-Full Flag and Almost-Empty Flag Offset

Values (IDT Standard and FWFT Modes) timing diagram.

FIFO WRITE/READ OPERATION

The state of the Port A data (A0-A35) lines is controlled by Port A Chip Select

(CSA) and Port A Write/Read select (W/RA). The A0-A35 lines are in the High-

impedance state when either CSA or W/RA is HIGH. The A0-A35 lines are

active outputs when both CSA and W/RA are LOW.

Data is loaded into FIFO1 from the A0-A35 inputs on a LOW-to-HIGH

transition of CLKA when CSA is LOW, W/RA is HIGH, ENA is HIGH, MBA is

LOW, and FFA/IRA is HIGH. Data is read from FIFO2 to the A0-A35 outputs

by a LOW-to-HIGH transition of CLKA when CSA is LOW, W/RA is LOW,

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Synchronized Synchronized

Number of Words in FIFO Memory(1,2) to CLKA to CLKB

IDT72V3654(3) IDT72V3664(3) IDT72V3674(3) EFA/ORA AEA AFB FFB/IRB

000LLHH

1 to X2 1 to X2 1 to X2 H L H H

(X2+1) to [2,048-(Y2+1)] (X2+1) to [4,096-(Y2+1)] (X2+1) to [8,192-(Y2+1)] H H H H

(2,048-Y2) to 2,047 (4,096-Y2) to 4,095 (8,192-Y2) to 8,191 H H L H

2,048 4,096 8,192 H H L L

TABLE 4 — FIFO1 FLAG OPERATION (IDT Standard and FWFT modes)

TABLE 5 — FIFO2 FLAG OPERATION (IDT Standard and FWFT modes)

Synchronized Synchronized

Number of Words in FIFO Memory(1,2) to CLKB to CLKA

IDT72V3654(3) IDT72V3664(3) IDT72V3674(3) EFB/ORB AEB AFA FFA/IRA

000LLHH

1 to X1 1 to X1 1 to X1 H L H H

(X1+1) to [2,048-(Y1+1)] (X1+1) to [4,096-(Y1+1)] (X1+1) to [8,192-(Y1+1)] H H H H

(2,048-Y1) to 2,047 (4,096-Y1) to 4,095 (8,192-Y1) to 8,191 H H L H

2,048 4,096 8,192 H H L L

ENA is HIGH, MBA is LOW, and EFA/ORA is HIGH (see Table 2). FIFO

reads and writes on Port A are independent of any concurrent Port B

operation.

The Port B control signals are identical to those of Port A with the

exception that the Port B Write/Read select (W/RB) is the inverse of the Port

A Write/Read select (W/RA). The state of the Port B data (B0-B35) lines is

controlled by the Port B Chip Select (CSB) and Port B Write/Read select

(W/RB). The B0-B35 lines are in the high-impedance state when either CSB

is HIGH or W/RB is LOW. The B0-B35 lines are active outputs when CSB is

LOW and W/RB is HIGH.

Data is loaded into FIFO2 from the B0-B35 inputs on a LOW-to-HIGH

transition of CLKB when CSB is LOW, W/RB is LOW, ENB is HIGH, MBB is

LOW, and FFB/IRB is HIGH. Data is read from FIFO1 to the B0-B35 outputs

by a LOW-to-HIGH transition of CLKB when CSB is LOW, W/RB is HIGH, ENB

is HIGH, MBB is LOW, and EFB/ORB is HIGH (see Table 3). FIFO reads and

writes on Port B are independent of any concurrent Port A operation.

The setup and hold time constraints to the port clocks for the port Chip

Selects and Write/Read selects are only for enabling write and read operations

NOTES:

1. When a word loaded to an empty FIFO is shifted to the output register, its previous FIFO memory location is free.

2. Data in the output register does not count as a "word in FIFO memory". Since in FWFT mode, the first word written to an empty FIFO goes unrequested to the output register (no read

operation necessary), it is not included in the FIFO memory count.

3. X1 is the Almost-Empty offset for FIFO1 used by AEB. Y1 is the Almost-Full offset for FIFO1 used by AFA. Both X1 and Y1 are selected during a FIFO1 reset or port A programming.

4. The ORB and IRA functions are active during FWFT mode; the EFB and FFA functions are active in IDT Standard mode.

NOTES:

1. When a word loaded to an empty FIFO is shifted to the output register, its previous FIFO memory location is free.

2. Data in the output register does not count as a "word in FIFO memory". Since in FWFT mode, the first word written to an empty FIFO goes unrequested to the output register (no read

operation necessary), it is not included in the FIFO memory count.

3. X2 is the Almost-Empty offset for FIFO2 used by AEA. Y2 is the Almost-Full offset for FIFO2 used by AFB. Both X2 and Y2 are selected during a FIFO2 reset or port A programming.

4. The ORA and IRB functions are active during FWFT mode; the EFA and FFB functions are active in IDT Standard mode.

and are not related to high-impedance control of the data outputs. If a port enable

is LOW during a clock cycle, the port’s Chip Select and Write/Read select may

change states during the setup and hold time window of the cycle.

When operating the FIFO in FWFT mode and the Output Ready flag is LOW,

the next word written is automatically sent to the FIFO’s output register by the

LOW-to-HIGH transition of the port clock that sets the Output Ready flag HIGH.

When the Output Ready flag is HIGH, subsequent data is clocked to the output

registers only when a read is selected using the port’s Chip Select, Write/Read

select, Enable, and Mailbox select.

When operating the FIFO in IDT Standard mode, the first word will cause

the Empty Flag to change state on the second LOW-to-HIGH transition of the

Read Clock. The data word will not be automatically sent to the output register.

Instead, data residing in the FIFO's memory array is clocked to the output

select, Enable, and Mailbox select. Write and read timing diagrams for Port A

can be found in Figure 7 and 14. Relevant Port B write and read cycle timing

diagrams together with Bus-Matching and Endian select operations can be

found in Figures 8 through 13.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

SYNCHRONIZED FIFO FLAGS

Each FIFO is synchronized to its port clock through at least two flip-flop

stages. This is done to improve flag-signal reliability by reducing the probability

of metastable events when CLKA and CLKB operate asynchronously to one

another. EFA/ORA, AEA, FFA/IRA, and AFA are synchronized to CLKA.

EFB/ORB, AEB, FFB/IRB, and AFB are synchronized to CLKB. Tables 4 and

5 show the relationship of each port flag to FIFO1 and FIFO2.

EMPTY/OUTPUT READY FLAGS (EFA/ORA, EFB/ORB)

These are dual purpose flags. In the FWFT mode, the Output Ready (ORA,

ORB) function is selected. When the Output-Ready flag is HIGH, new data is

present in the FIFO output register. When the Output Ready flag is LOW, the

previous data word is present in the FIFO output register and attempted FIFO

reads are ignored.

In the IDT Standard mode, the Empty Flag (EFA, EFB) function is selected.

When the Empty Flag is HIGH, data is available in the FIFO’s RAM memory

for reading to the output register. When the Empty Flag is LOW, the previous

data word is present in the FIFO output register and attempted FIFO reads are

ignored.

The Empty/Output Ready flag of a FIFO is synchronized to the port clock

that reads data from its array. For both the FWFT and IDT Standard modes,

the FIFO read pointer is incremented each time a new word is clocked to its

output register. The state machine that controls an Output Ready flag monitors

a write pointer and read pointer comparator that indicates when the FIFO

memory status is empty, empty+1, or empty+2.

In FWFT mode, from the time a word is written to a FIFO, it can be shifted

to the FIFO output register in a minimum of three cycles of the Output Ready

flag synchronizing clock. Therefore, an Output Ready flag is LOW if a word

in memory is the next data to be sent to the FlFO output register and three cycles

of the port Clock that reads data from the FIFO have not elapsed since the time

the word was written. The Output Ready flag of the FIFO remains LOW until

the third LOW-to-HIGH transition of the synchronizing clock occurs, simulta-

neously forcing the Output Ready flag HIGH and shifting the word to the FIFO

output register.

In IDT Standard mode, from the time a word is written to a FIFO, the Empty

Flag will indicate the presence of data available for reading in a minimum of

two cycles of the Empty Flag synchronizing clock. Therefore, an Empty Flag

is LOW if a word in memory is the next data to be sent to the FlFO output register

and two cycles of the port Clock that reads data from the FIFO have not elapsed

since the time the word was written. The Empty Flag of the FIFO remains LOW

until the second LOW-to-HIGH transition of the synchronizing clock occurs,

forcing the Empty Flag HIGH; only then can data be read.

A LOW-to-HIGH transition on an Empty/Output Ready flag synchronizing

clock begins the first synchronization cycle of a write if the clock transition occurs

at time tSKEW1 or greater after the write. Otherwise, the subsequent clock cycle

can be the first synchronization cycle (see Figures 15, 16, 17, and 18).

FULL/INPUT READY FLAGS (FFA/IRA, FFB/IRB)

This is a dual purpose flag. In FWFT mode, the Input Ready (IRA and IRB)

function is selected. In IDT Standard mode, the Full Flag (FFA and FFB)

function is selected. For both timing modes, when the Full/Input Ready flag is

HIGH, a memory location is free in the FIFO to receive new data. No memory

locations are free when the Full/Input Ready flag is LOW and attempted writes

to the FIFO are ignored.

The Full/Input Ready flag of a FlFO is synchronized to the port clock that

writes data to its array. For both FWFT and IDT Standard modes, each time

a word is written to a FIFO, its write pointer is incremented. The state machine

that controls a Full/Input Ready flag monitors a write pointer and read pointer

comparator that indicates when the FlFO memory status is full, full-1, or full-

2. From the time a word is read from a FIFO, its previous memory location is

ready to be written to in a minimum of two cycles of the Full/Input Ready flag

synchronizing clock. Therefore, an Full/Input Ready flag is LOW if less than

two cycles of the Full/Input Ready flag synchronizing clock have elapsed since

the next memory write location has been read. The second LOW-to-HIGH

transition on the Full/Input Ready flag synchronizing clock after the read sets

the Full/Input Ready flag HIGH.

A LOW-to-HIGH transition on a Full/Input Ready flag synchronizing clock

begins the first synchronization cycle of a read if the clock transition occurs at

time tSKEW1 or greater after the read. Otherwise, the subsequent clock cycle

can be the first synchronization cycle (see Figures 19, 20, 21, and 22).

ALMOST-EMPTY FLAGS (AEA, AEB)

The Almost-Empty flag of a FIFO is synchronized to the port clock that reads

data from its array. The state machine that controls an Almost-Empty flag

monitors a write pointer and read pointer comparator that indicates when the

FIFO memory status is almost-empty, almost-empty+1, or almost-empty+2.

The almost-empty state is defined by the contents of register X1 for AEB and

FIFO reset, programmed from Port A, or programmed serially (see Almost-

Empty flag and Almost-Full flag offset programming section). An Almost-

Empty flag is LOW when its FIFO contains X or less words and is HIGH when

its FIFO contains (X+1) or more words. A data word present in the FIFO output

Two LOW-to-HIGH transitions of the Almost-Empty flag synchronizing

clock are required after a FIFO write for its Almost-Empty flag to reflect the new

level of fill. Therefore, the Almost-Full flag of a FIFO containing (X+1) or more

words remains LOW if two cycles of its synchronizing clock have not elapsed

since the write that filled the memory to the (X+1) level. An Almost-Empty flag

is set HIGH by the second LOW-to-HIGH transition of its synchronizing clock

after the FIFO write that fills memory to the (X+1) level. A LOW-to-HIGH

transition of an Almost-Empty flag synchronizing clock begins the first synchro-

nization cycle if it occurs at time tSKEW2 or greater after the write that fills the

FIFO to (X+1) words. Otherwise, the subsequent synchronizing clock cycle

may be the first synchronization cycle. (See Figure 23 and 24).

ALMOST-FULL FLAGS (AFA, AFB)

The Almost-Full flag of a FIFO is synchronized to the port clock that writes

data to its array. The state machine that controls an Almost-Full flag monitors

a write pointer and read pointer comparator that indicates when the FIFO

memory status is almost-full, almost-full-1, or almost-full-2. The almost-full state

is defined by the contents of register Y1 for AFA and register Y2 for AFB. These

registers are loaded with preset values during a FlFO reset, programmed from

Port A, or programmed serially (see Almost-Empty flag and Almost-Full flag

offset programming section). An Almost-Full flag is LOW when the number of

words in its FIFO is greater than or equal to (2,048-Y), (4,096-Y), or (8,192-Y)

for the IDT72V3654, IDT72V3664, or IDT72V3674 respectively. An Almost-

Full flag is HIGH when the number of words in its FIFO is less than or equal

to [2,048-(Y+1)], [4,096-(Y+1)], or [8,192-(Y+1)] for the IDT72V3654,

IDT72V3664, or IDT72V3674 respectively. Note that a data word present in

the FIFO output register has been read from memory.

Two LOW-to-HIGH transitions of the Almost-Full flag synchronizing clock

are required after a FIFO read for its Almost-Full flag to reflect the new level

of fill. Therefore, the Almost-Full flag of a FIFO containing [2,048/4,096/8,192-

(Y+1)] or less words remains LOW if two cycles of its synchronizing clock have

not elapsed since the read that reduced the number of words in memory to

[2,048/4,096/8,192-(Y+1)]. An Almost-Full flag is set HIGH by the second

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

LOW-to-HIGH transition of its synchronizing clock after the FIFO read that

reduces the number of words in memory to [2,048/4,096/8,192-(Y+1)]. A

LOW-to-HIGH transition of an Almost-Full flag synchronizing clock begins the

first synchronization cycle if it occurs at time tSKEW2 or greater after the read

that reduces the number of words in memory to [2,048/4,096/8,192-(Y+1)].

Otherwise, the subsequent synchronizing clock cycle may be the first synchro-

nization cycle (see Figure 25 and 26).

MAILBOX REGISTERS

Each FIFO has a 36-bit bypass register to pass command and control

information between Port A and Port B without putting it in queue. The Mailbox

select (MBA, MBB) inputs choose between a mail register and a FIFO for a

port data transfer operation. The usable width of both the Mail1 and Mail2

registers matches the selected bus size for Port B.

A LOW-to-HIGH transition on CLKA writes data to the Mail 1 Register when

a Port A write is selected by CSA, W/RA, and ENA with MBA HIGH. If the

selected Port B bus size is also 36 bits, then the usable width of the Mail1 register

employs data lines A0-A35. If the selected Port B bus size is 18 bits, then the

usable width of the Mail1 Register employs data lines A0-A17. (In this case,

A18-A35 are don’t care inputs.) If the selected Port B bus size is 9 bits, then

the usable width of the Mail1 Register employs data lines A0-A8. (In this case,

A9-A35 are don’t care inputs.)

A LOW-to-HIGH transition on CLKB writes B0-B35 data to the Mail2

HIGH. If the selected Port B bus size is also 36 bits, then the usable width of

the Mail2 employs data lines B0-B35. If the selected Port B bus size is 18 bits,

then the usable width of the Mail2 Register employs data lines B0-B17. (In this

case, B18-B35 are don’t care inputs.) If the selected Port B bus size is 9 bits,

then the usable width of the Mail2 Register employs data lines B0-B8. (In this

case, B9-B35 are don’t care inputs.)

Writing data to a mail register sets its corresponding flag (MBF1 or MBF2)

LOW. Attempted writes to a mail register are ignored while the mail flag is LOW.

When data outputs of a port are active, the data on the bus comes from the

FIFO output register when the port Mailbox select input is LOW and from the

mail register when the port Mailbox select input is HIGH.

The Mail1 Register Flag (MBF1) is set HIGH by a LOW-to-HIGH transition

on CLKB when a Port B read is selected by CSB, W/RB, and ENB with MBB

HIGH. For a 36-bit bus size, 36 bits of mailbox data are placed on B0-B35.

For an 18-bit bus size, 18 bits of mailbox data are placed on B0-B17. (In this

case, B18-B35 are indeterminate.) For a 9-bit bus size, 9 bits of mailbox data

are placed on B0-B8. (In this case, B9-B35 are indeterminate.)

The Mail2 Register Flag (MBF2) is set HIGH by a LOW-to-HIGH transition

on CLKA when a Port A read is selected by CSA, W/RA, and ENA with MBA

HIGH.

For a 36-bit bus size, 36 bits of mailbox data are placed on A0-A35. For

an 18-bit bus size, 18 bits of mailbox data are placed on A0-A17. (In this case,

A18-A35 are indeterminate.) For a 9-bit bus size, 9 bits of mailbox data are

placed on A0-A8. (In this case, A9-A35 are indeterminate.)

The data in a mail register remains intact after it is read and changes only

when new data is written to the register. The Endian select feature has no effect

on mailbox data. For mail register and Mail Register Flag timing diagrams, see

Figure 27 and 28.

BUS SIZING

The Port B bus can be configured in a 36-bit long word, 18-bit word, or

9-bit byte format for data read from FIFO1 or written to FIFO2. The levels

applied to the Port B Bus Size select (SIZE) and the Bus-Match select (BM)

determine the Port B bus size. These levels should be static throughout FIFO

operation. Both bus size selections are implemented at the completion of

Master Reset, by the time the Full/Input Ready flag is set HIGH, as shown in

Figure 2.

Two different methods for sequencing data transfer are available for Port

B when the bus size selection is either byte- or word-size. They are referred

to as Big-Endian (most significant byte first) and Little-Endian (least significant

byte first). The level applied to the Big-Endian select (BE) input during the LOW-

to-HIGH transition of MRS1 and MRS2 selects the endian method that will be

active during FIFO operation. BE is a don’t care input when the bus size

selected for Port B is long word. The endian method is implemented at the

completion of Master Reset, by the time the Full/Input Ready flag is set HIGH,

as shown in Figure 2.

Only 36-bit long word data is written to or read from the two FIFO memories

on the IDT72V3654/72V3664/72V3674. Bus-matching operations are done

after data is read from the FIFO1 RAM and before data is written to the FIFO2

RAM. These bus-matching operations are not available when transferring

data via mailbox registers. Furthermore, both the word- and byte-size bus

selections limit the width of the data bus that can be used for mail register

operations. In this case, only those byte lanes belonging to the selected word-

or byte-size bus can carry mailbox data. The remaining data outputs will be

indeterminate. The remaining data inputs will be don’t care inputs. For

example, when a word-size bus is selected, then mailbox data can be

transmitted only between A0-A17 and B0-B17. When a byte-size bus is

selected, then mailbox data can be transmitted only between A0-A8 and B0-

B8. (See Figures 27 and 28).

BUS-MATCHING FIFO1 READS

Data is read from the FIFO1 RAM in 36-bit long word increments. If a long

word bus size is implemented, the entire long word immediately shifts to the

FIFO1 output register. If byte or word size is implemented on Port B, only the

first one or two bytes appear on the selected portion of the FIFO1 output register,

with the rest of the long word stored in auxiliary registers. In this case,

subsequent FIFO1 reads output the rest of the long word to the FIFO1 output

When reading data from FIFO1 in byte or word format, the unused B0-B35

outputs are indeterminate.

BUS-MATCHING FIFO2 WRITES

Data is written to the FIFO2 RAM in 36-bit long word increments. Data written

to FIFO2 with a byte or word bus size stores the initial bytes or words in auxiliary

registers. The CLKB rising edge that writes the fourth byte or the second word

of long word to FIFO2 also stores the entire long word in the FIFO2 memory.

The bytes are arranged in the manner shown in Figure 2.

When writing data to FIFO2 in byte or word format, the unused B0-B35 inputs

are don't care inputs.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 2. Bus Sizing

A35  A27 A26  A18 A17  A9 A8  A0

B35  B27 B26  B18 B17  9 B8  B0

B35  B27 B26  B18 B17  B9 B8  B0

(a) LONG WORD SIZE

(b) WORD SIZE  BIG ENDIAN

(d) BYTE SIZE  BIG-ENDIAN

Write to FIFO1/

Read from FIFO2

Read from FIFO1/

Write to FIFO2

1st: Read from FIFO1/

Write to FIFO2

BE BM SIZE

H H L

L H L

H H H

X L X

BYTE ORDER ON PORT A:

B35  B27 B26  B18 B17  B9 B8  B0

BE BM SIZE

2nd: Read from FIFO1/

Write to FIFO2

3rd: Read from FIFO1/

Write to FIFO2

4th: Read from FIFO1/

Write to FIFO2

B35  B27 B26  B18 B17  B9 B8  B0

1st: Read from FIFO1/

Write to FIFO2

1st: Read from FIFO1/

Write to FIFO2

2nd: Read from FIFO1/

Write to FIFO2

2nd: Read from FIFO1/

Write to FIFO2

(e) BYTE SIZE  LITTLE-ENDIAN

1st: Read from FIFO1/

Write to FIFO2

BE BM SIZE

L H H

2nd: Read from FIFO1/

Write to FIFO2

3rd: Read from FIFO1/

Write to FIFO2

4th: Read from FIFO1/

Write to FIFO2

B35  B27 B26  B18 B17  B9 B8  B0

4664 drw 04

BYTE ORDER ON PORT B:

B35  B27 B26  B18 B17  B9 B8  B0

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTES:

1. Partial Reset is performed in the same manner for FIFO2.

2. MRS1 must be HIGH during Partial Reset.

3. If BE/FWFT is HIGH, then EFB/ORB will go LOW one CLKB cycle earlier than in this case where BE/FWFT is LOW.

Figure 3. FIFO1 Master Reset and Loading X1 and Y1 with a Preset Value of Eight(1) (IDT Standard and FWFT Modes)

Figure 4. FIFO1 Partial Reset(1) (IDT Standard and FWFT Modes)

NOTES:

1. FIFO2 Master Reset (MRS2) is performed in the same manner to load X2 and Y2 with a preset value. For FIFO2 Master Reset, MRS1 must toggle simultaneously with MRS2.

2. PRS1 must be HIGH during Master Reset.

3. If BE/FWFT is HIGH, then EFB/ORB will go LOW one CLKB cycle earlier than in this case where BE/FWFT is LOW.

CLKA

MRS1

FFA/IRA

AEB

AFA

MBF1

CLKB

EFB/ORB

FS2,

FS1,FS0

4664 drw 05

tRSTS tRSTH

tFSHtFSS

tWFF tWFF

tREF

tRSF

0,1

tRSF

BE/FWFT FWFT

tBES tBEH tFWS

(3)

RTM LOW

CLKA

PRS1

FFA/IRA

AEB

AFA

MBF1

CLKB

EFB/ORB

4664 drw 06

RSTS

RSTH

WFF

REF(3)

RSF

RTM LOW

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 6. Serial Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values (IDT Standard and FWFT Modes)

Figure 5. Parallel Programming of the Almost-Full Flag and Almost-Empty Flag Offset Values after Reset (IDT Standard and FWFT Modes)

NOTES:

1. tSKEW1 is the minimum time between the rising CLKA edge and a rising CLKB edge for FFB/IRB to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising

edge of CLKB is less than tSKEW1, then FFB/IRB may transition HIGH one CLKB cycle later than shown.

2. It is not necessary to program offset register bits on consecutive clock cycles. FIFO write attempts are ignored until FFA/IRA and FFB/IRB is set HIGH.

3. Programmable offsets are written serially to the SD input in the order AFA offset (Y1), AEB offset (X1), AFB offset (Y2), and AEA offset (X2).

NOTES:

1. tSKEW1 is the minimum time between the rising CLKA edge and a rising CLKB edge for FFB/IRB to transition HIGH in the next cycle. If the time between the rising edge of CLKA and rising

edge of CLKB is less than tSKEW1, then FFB/IRB may transition HIGH one CLKB cycle later than shown.

2. CSA=LOW, W/RA=HIGH,MBA=LOW. It is not necessary to program offset register on consecutive clock cycles.

4664 drw 07

CLKA

MRS1,

MRS2

FFA/IRA

CLKB

FFB/IRB

A0-A35

FS1,FS0

ENA

tFSH

tWFF

tENHtENS2 tSKEW1

tDS tDH

tWFF

0,0

AFA Offset

(Y1)

AEB Offset

(X1)

AFB Offset

(Y 2)

AEA Offset

(X 2)

First Word to FIFO1

(1)

tFSH

tFSS

FS2

CLKA

FFA/IRA

SENS

SENH

FS0/SD

(3)

SPH

SENS

SENH

FSS

WFF

FS1/SEN

AEA Offset (X2) LSB

SDS

SDH

SDS

SDH

AFA Offset (Y1) MSB

MRS1,

MRS2

4664 drw 08

FSS

FSH

CLKB 4

FS2

FFB/IRB

WFF

SKEW(1)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTE:

1. Written to FIFO1. Figure 7. Port A Write Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

DATA SIZE TABLE FOR LONG-WORD WRITES TO FIFO2

Figure 8. Port B Long-Word Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

SIZE MODE(1) DATA WRITTEN TO FIFO2 DATA READ FROM FIFO2

BM SIZE BE B35-B27 B26-B18 B17-B9 B8-B0 A35-A27 A26-A18 A17-A9 A8-A0

LXXA B C D ABCD

NOTE:

1. BE is selected at Master Reset: BM and SIZE must be static throughout device operation.

NOTE:

1. Written to FIFO2.

4664 drw09

CLKA

FFA/IRA

ENA

A0 - A35

MBA

CSA

W/RA

CLKH

CLKL

CLK

ENS1

ENS2

ENH

(1)

ENS2

ENH

ENS2

No Operation

HIGH

4664 drw 10

CLKB

FFB/IRB

ENB

B0-B35

MBB

CSB

W/RB

tCLK

tCLKH tCLKL

tENH

tDH

(1)

tENS2

tDS

tENS2

tENS1

tENH

tENS2

No Operation

HIGH

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

SIZE MODE(1) WRITE DATA WRITTEN DATA READ FROM FIFO2

NO. TO FIFO2

BM SIZE BE B17-B9 B8-B0 A35-A27 A26-A18 A17-A9 A8-A0

HL H A B C D

HL L A B C D

DATA SIZE TABLE FOR WORD WRITES TO FIFO2

1A B

2C D

1C D

2A B

Figure 9. Port B Word Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation.

SIZE MODE(1) WRITE DATA WRITTEN DATA READ FROM FIFO2

NO. TO FIFO2

BM SIZE BE B8-B0 A35-A27 A26-A18 A17-A9 A8-A0

HHH A B C D

HH L A B C D

1 A

2 B

3 C

4 D

1 D

2 C

3 B

4 A

DATA SIZE TABLE FOR BYTE WRITES TO FIFO2

Figure 10. Port B Byte Write Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation.

CLKB

ENB

tENH tENH

FFB/IRB

W/RB

CSB

tENH

HIGH

4664 drw 11

B0-B17

tENH

MBB

tDH

tDS

tENS2

tENS1

tENS2

FFB/IRB

CSB

W/RB

CLKB

tENHtENS2

ENB

4664 drw 12

HIGH

B0-B8

tENS2 tENH

tENS2

tENH

tDS tDH

tENS1

tENH

MBB

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

SIZE MODE(1) DATA WRITTEN TO FIFO1 READ DATA READ FROM FIFO1

NO.

BM SIZE BE A35-A27 A26-A18 A17-A9 A8-A0 B17-B9 B8-B0

HLH A B C D1 A B

2C D

HLL A B C D1 C D

2A B

DATA SIZE TABLE FOR WORD READS FROM FIFO1

Figure 12. Port-B Word Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation .

SIZE MODE(1) DATA WRITTEN TO FIFO1 DATA READ FROM FIFO1

BM SIZE BE A35-A27 A26-A18 A17-A9 A8-A0 B35-B27 B26-B18 B17-B9 B8-B0

LX X A B C D A B C D

NOTE:

1. Read From FIFO1.

DATA SIZE TABLE FOR FIFO LONG-WORD READS FROM FIFO1

Figure 11. Port B Long-Word Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

NOTE:

1. Unused word B18-B35 are indeterminate for word-size reads.

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation .

4664 drw 13

CLKB

EFB/ORB

ENB

MBB

CSB

W/RB

CLK

CLKH

CLKL

ENS2

MDV

ENS2

ENH

ENS2

ENH

W1 W2 W3

(1) (1)

ENH

DIS

No Operation

B0-B35

(FWFT Mode)

DIS

Previous Data

B0-B35

(Standard Mode)

MDV

OR t

HIGH

(1)(1)

(1)

CLKB

ENB

EFB/ORB

W/RB

CSB

HIGH

4664 drw 14

B0-B17

(Standard Mode)

B0-B17

(FWFT Mode)

Previous Data

tDIS

tENS2 tENH

No Operation

tDIS

MBB

tEN

tMDV

tEN tMDV

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

DATA SIZE TABLE FOR BYTE READS FROM FIFO1

SIZE MODE(1) DATA WRITTEN TO FIFO1 READ DATA READ FROM FIFO1

NO.

BM SIZE BE A35-A27 A26-A18 A17-A9 A8-A0 B8-B0

HH H A B C D

HH L A B C D

1 A

2 B

3 C

4 D

1 D

2 C

3 B

4 A

NOTE:

1. BE is selected at Master Reset; BM and SIZE must be static throughout device operation.

Figure 13. Port-B Byte Read Cycle Timing for FIFO1 (IDT Standard and FWFT Modes)

Figure 14. Port-A Read Cycle Timing for FIFO2 (IDT Standard and FWFT Modes)

NOTE:

1. Unused bytes B9-B17, B18-B26, and B27-B35 are indeterminate for byte-size reads.

NOTE:

1. Read From FIFO2.

EFB/ORB

MBB

CSB

W/RB

ENB

CLKB

HIGH

B0-B8

B0-B8 Read 5Read 2 Read 3

Read 4Read 3

Previous Data Read 2

No Operation

DIS

ENS2

ENH

(Standard Mode)

(FWFT Mode)

MDV

4664 drw 15

4664 drw16

CLKA

EFA/ORA

ENA

MBA

CSA

W/RA

CLK

CLKH

CLKL

ENS2

MDV

ENS2

ENH

ENS2

ENH

W1 W2 W3

(1) (1)

ENH

DIS

No Operation

A0-A35

(FWFT Mode)

(1) (1)

DIS

W1Previous Data

A0-A35

(Standard Mode)

MDV

OR t

HIGH

(1)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTES:

1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKB edge for ORB to transition HIGH and to clock the next word to the FIFO1 output register in three CLKB cycles.

If the time between the rising CLKA edge and rising CLKB edge is less than tSKEW1, then the transition of ORB HIGH and load of the first word to the output register may occur one CLKB

cycle later than shown.

2. If Port B size is word or byte, ORB is set LOW by the last word or byte read from FIFO1, respectively.

Figure 15. ORB Flag Timing and First Data Word Fall Through when FIFO1 is Empty (FWFT Mode)

CSA

WRA

MBA

IRA

A0-A35

CLKB

ORB

CSB

W/RB

MBB

ENA

ENB

B0-B35

CLKA

4664 drw17

123

tCLKH tCLKL

tCLK

tENS2

tENH

tDS tDH

tSKEW1

tCLKtCLKL

tREF tREF

tENS2 tENH

Old Data in FIFO1 Output Register W1

FIFO1 Empty

LOW

HIGH

LOW

HIGH

LOW

tCLKH

HIGH

(1)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTES:

1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKB edge for EFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than tSKEW1, then the transition of EFB HIGH may occur one CLKB cycle later than shown.

2. If Port B size is word or byte, EFB is set LOW by the last word or byte read from FIFO1, respectively.

Figure 16.

EFB

Flag Timing and First Data Read Fall Through when FIFO1 is Empty (IDT Standard Mode)

CSA

WRA

MBA

FFA

A0-A35

CLKB

EFB

CSB

W/RB

MBB

ENA

ENB

B0-B35

CLKA

4664 drw18

CLKH

CLKL

CLK

ENS2

ENH

SKEW1

CLK

CLKL

ENS2

ENH

FIFO1 Empty

LOW

HIGH

LOW

HIGH

LOW

CLKH

HIGH

(1)

REF

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTES:

1. tSKEW1 is the minimum time between a rising CLKB edge and a rising CLKA edge for ORA to transition HIGH and to clock the next word to the FIFO2 output register in three CLKA cycles.

If the time between the CLKB edge and the rising CLKA edge is less than tSKEW1, then the transition of ORA HIGH and load of the first word to the output register may occur one CLKA

cycle later than shown.

2. If Port B size is word or byte, tSKEW1 is referenced to the rising CLKB edge that writes the last word or byte of the long word, respectively.

Figure 17. ORA Flag Timing and First Data Word Fall through when FIFO2 is Empty (FWFT Mode)

CSB

W/RB

MBB

IRB

B0-B35

CLKA

ORA

CSA

W/RA

MBA

ENB

ENA

A0-A35

CLKB

4664 drw19

123

tCLKH tCLKL

tCLK

tENS2

tENH

tDS tDH

tSKEW1

(1)

tCLK

tCLKH

tREF tREF

tENS2 tENH

Old Data in FIFO2 Output Register W1

FIFO2 Empty

tCLKL

LOW

HIGH

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTES:

1. tSKEW1 is the minimum time between a rising CLKB edge and a rising CLKA edge for EFA to transition HIGH in the next CLKA cycle. If the time between the rising CLKB edge and rising

CLKA edge is less than tSKEW1, then the transition of EFA HIGH may occur one CLKA cycle later than shown.

2. If Port B size is word or byte, tSKEW1 is referenced to the rising CLKB edge that writes the last word or byte of the long word, respectively.

Figure 18.

EFA

Flag Timing and First Data Read when FIFO2 is Empty (IDT Standard Mode)

CSB

W/RB

MBB

FFB

B0-B35

CLKA

EFA

CSA

W/RA

MBA

ENB

ENA

A0-A35

CLKB

4664 drw20

CLKH

CLKL

CLK

ENS2

ENH

SKEW1

(1) t

CLK

CLKL

ENS2

ENH

FIFO2 Empty

LOW

CLKH

HIGH

REF

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 20.

FFA

Flag Timing and First Available Write when FIFO1 is Full (IDT Standard Mode)

Figure 19. IRA Flag Timing and First Available Write when FIFO1 is Full (FWFT Mode)

NOTES:

1. tSKEW1 is the minimum time between a rising CLKB edge and a rising CLKA edge for FFA to transition HIGH in the next CLKA cycle. If the time between the

rising CLKB edge and rising CLKA edge is less than tSKEW1, then FFA may transition HIGH one CLKA cycle later than shown.

2. If Port B size is word or byte, tSKEW1 is referenced from the rising CLKB edge that reads the last word or byte of the long word, respectively.

NOTES:

1. tSKEW1 is the minimum time between a rising CLKB edge and a rising CLKA edge for IRA to transition HIGH in the next CLKA cycle. If the time between the rising

CLKB edge and rising CLKA edge is less than tSKEW1, then IRA may transition HIGH one CLKA cycle later than shown.

2. If Port B size is word or byte, tSKEW1 is referenced to the rising CLKB edge that reads the last word or byte write of the long word, respectively.

CSB

ORB

W/RB

MBB

ENB

B0-B35

CLKB

IRA

CLKA

CSA

4664 drw21

W/RA

A0-A35

MBA

ENA

tCLK

tCLKH tCLKL

tENS2 tENH

tSKEW1 tCLK

tCLKH tCLKL

tWFF

tENS2

tDS

tENH

tDH

To FIFO1

Previous Word in FIFO1 Output Register Next Word From FIFO1

LOW

HIGH

LOW

HIGH

LOW

HIGH

(1)

FIFO1 Full

tWFF

Write

CSB

EFB

MBB

ENB

B0-B35

CLKB

FFA

CLKA

CSA

4664 drw22

W/RA

A0-A35

MBA

ENA

CLK

CLKH

CLKL

ENS2

ENH

SKEW1

CLK

CLKH

CLKL

ENS2

ENH

To FIFO1

Previous Word in FIFO1 Output Register Next Word From FIFO1

LOW

W/RB HIGH

LOW

HIGH

LOW

HIGH

(1)

FIFO1 Full

WFF

Write

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

NOTES:

1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKB edge for IRB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than tSKEW1, then IRB may transition HIGH one CLKB cycle later than shown.

2. If Port B size is word or byte, IRB is set LOW by the last word or byte write of the long word, respectively.

Figure 21. IRB Flag Timing and First Available Write when FIFO2 is Full (FWFT Mode)

CSA

ORA

W/RA

MBA

ENA

A0-A35

CLKA

IRB

CLKB

CSB

4664 drw23

W/RB

B0-B35

MBB

ENB

CLK

CLKH

CLKL

ENS2

ENH

SKEW1

CLK

CLKH

CLKL

WFF

ENS2

ENH

To FIFO2

Previous Word in FIFO2 Output Register Next Word From FIFO2

FIFO2 FULL

LOW

HIGH

LOW

(1)

Write

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 22.

FFB

Flag Timing and First Available Write when FIFO2 is Full (IDT Standard Mode)

NOTES:

1. tSKEW1 is the minimum time between a rising CLKA edge and a rising CLKB edge for FFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than tSKEW1, then FFB may transition HIGH one CLKB cycle later than shown.

2. If Port B size is word or byte, FFB is set LOW by the last word or byte write of the long word, respectively.

CSA

EFA

MBA

ENA

A0-A35

CLKA

FFB

CLKB

CSB

4664 drw24

W/RB

B0-B35

MBB

ENB

tCLK

tCLKH tCLKL

tENS2 tENH

tSKEW1 tCLK

tCLKH tCLKL

tENS2

tDS

tENH

tDH

To FIFO2

Previous Word in FIFO2 Output Register Next Word From FIFO2

LOW

W/RALOW

LOW

HIGH

LOW

(1)

FIFO2 Full

tWFF tWFF

Write

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 25. Timing for

AFA

when FIFO1 is Almost-Full (IDT Standard and FWFT Modes)

Figure 23. Timing for

AEB

when FIFO1 is Almost-Empty (IDT Standard and FWFT Modes)

Figure 24. Timing for

AEA

when FIFO2 is Almost-Empty (IDT Standard and FWFT Modes)

NOTES:

1. tSKEW2 is the minimum time between a rising CLKA edge and a rising CLKB edge for AEB to transition HIGH in the next CLKB cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than tSKEW2, then AEB may transition HIGH one CLKB cycle later than shown.

2 . FIFO1 Write (CSA = LOW, W/RA = LOW, MBA = LOW), FIFO1 read (CSB = LOW, W/RB = HIGH, MBB = LOW). Data in the FIFO1 output register has been read from the FIFO.

3. If Port B size is word or byte, AEB is set LOW by the last word or byte read from FIFO1, respectively.

NOTES:

1. tSKEW2 is the minimum time between a rising CLKA edge and a rising CLKB edge for AFA to transition HIGH in the next CLKA cycle. If the time between the rising CLKA edge and rising

CLKB edge is less than tSKEW2, then AFA may transition HIGH one CLKA cycle later than shown.

2 . FIFO1 Write (CSA = LOW, W/RA = HIGH, MBA = LOW), FIFO1 read (CSB = LOW, W/RB = HIGH, MBB = LOW). Data in the FIFO1 output register has been read from the FIFO.

3. D = Maximum FIFO Depth = 2,048 for the IDT72V3654, 4,096 for the IDT72V3664, 8,192 for the IDT72V3674.

4. If Port B size is word or byte, tSKEW2 is referenced to the rising CLKB edge that reads the last word or byte of the long word, respectively.

AEB

CLKA

ENB

4664 drw 25

ENA

CLKB 2

ENS2

ENH

SKEW2

PAE

ENS2

ENH

X1 Words in FIFO1 (X1+1) Words in FIFO1

(1)

AEA

CLKB

ENA

4664 drw 26

ENB

CLKA 2

ENS2

ENH

SKEW2

PAE

ENS2

ENH

(X2+1) Words in FIFO2

X2 Words in FIFO2

(1)

AFA

CLKA

ENB

4664 drw 27

ENA

CLKB

SKEW2

ENS2

ENH

PAF

ENS2

ENH

PAF

[D-(Y1+1)] Words in FIFO1 (D-Y1) Words in FIFO1

(1)

NOTES:

1. tSKEW2 is the minimum time between a rising CLKB edge and a rising CLKA edge for AEA to transition HIGH in the next CLKA cycle. If the time between the rising CLKB edge and rising

CLKA edge is less than tSKEW2, then AEA may transition HIGH one CLKA cycle later than shown.

2 . FIFO2 Write (CSB = LOW, W/RB = LOW, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW). Data in the FIFO2 output register has been read from the FIFO.

3. If Port B size is word or byte, tSKEW2 is referenced to the rising CLKB edge that writes the last word or byte of the long word, respectively.

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 26. Timing for

AFB

when FIFO2 is Almost-Full (IDT Standard and FWFT Modes)

Figure 27. Timing for Mail1 Register and

MBF1

Flag (IDT Standard and FWFT Modes)

NOTE:

1 . If Port B is configured for word size, data can be written to the Mail1 register using A0-A17 (A18-A35 are don't care inputs). In this first case B0-B17 will have valid data (B18-B35

will be indeterminate). If Port B is configured for byte size, data can be written to the Mail1 Register using A0-A8 (A9-A35 are don't care inputs). In this second case, B0-B8 will

have valid data (B9-B35 will be indeterminate).

NOTES:

1. tSKEW2 is the minimum time between a rising CLKB edge and a rising CLKA edge for AFB to transition HIGH in the next CLKB cycle. If the time between the rising CLKB edge and rising

CLKA edge is less than tSKEW2, then AFB may transition HIGH one CLKB cycle later than shown.

2 . FIFO2 write (CSB = LOW, W/RB = LOW, MBB = LOW), FIFO2 read (CSA = LOW, W/RA = LOW, MBA = LOW). Data in the FIFO2 output register has been read from the FIFO.

3. D = Maximum FIFO Depth = 2,048 for the IDT72V3654, 4,096 for the IDT72V3664, 8,192 for the IDT72V3674.

4. If Port B size is word or byte, AFB is set LOW by the last word or byte write of the long word, respectively.

AFB

CLKB

ENA

4664 drw 28

ENB

CLKA

tSKEW2

tENS2 tENH

tPAF

tENS2 tENH

tPAF

[D-(Y2+1)] Words in FIFO2 (D-Y2) Words in FIFO2

(1)

4664 drw29

CLKA

ENA

A0-A35

MBA

CSA

W/RA

CLKB

MBF1

CSB

MBB

ENB

B0-B35

W/RB

tENS1 tENH

tDS tDH

tPMF tPMF

tENS2 tENH

tDIS

tEN tMDV

tPMR

FIFO1 Output Register W1 (Remains valid in Mail1 Register after read)

tENS1 tENH

tENS2 tENH

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 28. Timing for Mail2 Register and

MBF2

Flag (IDT Standard and FWFT Modes)

NOTE:

1. If Port B is configured for word size, data can be written to the Mail2 Register using B0-B17 (B18-B35 are don’t care inputs). In this first case A0-A17 will have valid data

(A18-A35 will be indeterminate). If Port B is configured for byte size, data can be written to the Mail2 Register using B0-B8 (B9-B35 are don’t care inputs). In this second

case, A0-A8 will have valid data (A9-A35 will be indeterminate).

4664 drw30

CLKB

ENB

B0-B35

MBB

CSB

W/RB

CLKA

MBF2

CSA

MBA

ENA

A0-A35

W/RA

tENS1 tENH

tDH

tPMF tPMF

tENS2 tENH

tDIS

tEN tMDV

tPMR

FIFO2 Output Register W1 (Remains valid in Mail 2 Register after read)

tENS1 tENH

tENH

tENS2

tDS

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

CLKA

ENB

CLKB

RT1

4664 drw31

RSTS

RSTH

REF

(2)

B0-Bn

RTM

EFB

REF

(2)

1342

RTMS

RTMH

ENS2

ENH

NOTES:

1. CSB = LOW

2. Retransmit setup is complete after EFB returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO1 after Master Reset on FIFO1.

4 . No more than D-2 may be written to the FIFO1 between Reset of FIFO1 (Master or Partial) and Retransmit setup. Therefore, FFA will be LOW throughout the Retransmit

setup procedure. D = 2,048, 4,096 and 8,192 for the IDT72V3654, IDT72V3664 and IDT72V3674 respectively.

Figure 29. Retransmit Timing for FIFO1 (IDT Standard Mode)

CLKB

ENA

CLKA

RT2

4664 drw32

tRSTS tRSTH

tREF

(2)

A0-An

RTM

EFA tREF

(2)

1342

tRTMS tRTMH

tENS2 tENH

NOTES:

1. CSA = LOW

2. Retransmit setup is complete after EFA returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO1 after Master Reset on FIFO2.

4 . No more than D-2 may be written to the FIFO1 between Reset of FIFO2 (Master or Partial) and Retransmit setup. Therefore, FFB will be LOW throughout the Retransmit

setup procedure. D = 2,048, 4,096 and 8,192 for the IDT72V3654, IDT72V3664 and IDT72V3674 respectively.

Figure 30. Retransmit Timing for FIFO2 (IDT Standard Mode)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

CLKA

ENB

CLKB

RT1

4664 drw33

RSTS

RSTH

REF

(2)

B0-Bn

RTM

ORB

REF

(2)

1342

RTMS

RTMH

LOW

NOTES:

1. CSB = LOW

2. Retransmit setup is complete after ORB returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO1 after Master Reset on FIFO1.

4 . No more than D-2 may be written to the FIFO1 between Reset of FIFO1 (Master or Partial) and Retransmit setup. Therefore, IRA will be LOW throughout the Retransmit

setup procedure. D = 2,049, 4,097 and 8,193 for the IDT72V3654, IDT72V3664 and IDT72V3674 respectively.

Figure 31. Retransmit Timing for FIFO1 (FWFT Mode)

CLKB

ENA

CLKA

RT2

4664 drw34

RSTS

RSTH

REF

(2)

A0-An

RTM

ORA

REF

(2)

1342

RTMS

RTMH

LOW

NOTES:

1. CSA = LOW

2. Retransmit setup is complete after ORA returns HIGH, only then can a read operation begin.

3. W1 = first word written to the FIFO2 after Master Reset on FIFO2.

4 . No more than D-2 may be written to the FIFO2 between Reset of FIFO2 (Master or Partial) and Retransmit setup. Therefore, IRB will be LOW throughout the Retransmit

setup procedure. D = 2,049, 4,097 and 8,193 for the IDT72V3654, IDT72V3664 and IDT72V3674 respectively.

Figure 32. Retransmit Timing for FIFO2 (FWFT Mode)

COMMERCIAL TEMPERATURE RANGE

IDT72V3654/72V3664/72V3674 3.3V CMOS SyncBiFIFOTM WITH BUS-MATCHING

2,048 x 36 x 2, 4,096 x 36 x 2 and 8,192 x 36 x 2

Figure 33. Output Load and AC Test Conditions

NOTE:

1. Includes probe and jig capacitance.

4664 drw 35

PARAMETER MEASUREMENT INFORMATION

From Output

Under Test

30 pF

330 Ω

3.3V

510 Ω

PROPAGATION DELAY

LOAD CIRCUIT

3 V

GND

Timing

Input

Data,

Enable

Input

GND

3 V

1.5 V

VOLTAGE WAVEFORMS

SETUP AND HOLD TIMES VOLTAGE WAVEFORMS

PULSE DURATIONS

VOLTAGE WAVEFORMS

ENABLE AND DISABLE TIMES VOLTAGE WAVEFORMS

PROPAGATION DELAY TIMES

3 V

GND

3 V

1.5 V

Output

Enable

Low-Level

Output

High-Level

Output

3 V

GND

≈3 V

1.5 V 1.5 V

1.5 V

≈O V

GND

1.5 V 1.5 V

Input

In-Phase

Output

High-Level

Input

Low-Level

Input

1.5 V

3 V

PLZ

PHZ

PZL

PZH

(1)

CORPORATE HEADQUARTERS for SALES: for Tech Support:

6024 Silver Creek Valley Road 800-345-7015 or 408-284-8200 408-360-1753

San Jose, CA 95138 fax: 408-284-2775 em ail: FI FOhe lp@idt .co m

www.idt.com

ORDERING INFORMATION

BLANK

72V3654

72V3664

72V3674

4664 drw36

Commercial (0°C to +70°C)

Thin Quad Flat Pack (TQFP, PK128-1)

Low Power

2,048 x 36 x 2  3.3V SyncBiFIFO with Bus-Matching

4,096 x 36 x 2  3.3V SyncBiFIFO with Bus-Matching

8,192 x 36 x 2  3.3V SyncBiFIFO with Bus-Matching

XXXXXX

IDT

Device Type

XXX X X

Power Speed Package Process/

Temperature

Range

Clock Cycle Time (t

CLK

)

Speed in Nanoseconds

Commercial Only

NOTE:

1. Industrial temperature range is available by special order.

DATASHEET DOCUMENT HISTORY

06/13/2000 pgs. 1-3, 5, 6, 8-10, 12-14, 16, 19, 20, 23-33, and 37.

09/25/2000 pgs. 7, 9, 10 and 37.

12/22/2000 pgs. 4, 5 and 13.

02/08/2001 pgs. 5 and 12.

03/21/2001 pgs. 7 and 8.

11/03/2003 pg. 1.