10

COMMERCIALTEMPERATURERANGE

IDT72420/72200/72210/72220/72230/72240 CMOS SYNCFIFO™

64 x 8, 256 x 8, 512 x 8, 1,024 x 8, 2,048 x 8, 4,096 x 8

Figure 10. Block Diagram of Single 64 x 8, 256 x 8, 512 x 8, 1,024 x 8, 2,048 x 8, 4,096 x 8 Synchronous FIFO

WIDTH EXPANSION CONFIGURATION - Word width may be increased

simply by connecting the corresponding input control signals of multiple

devices. A composite flag should be created for each of the endpoint status

flags (EF and FF) The partial status flags (AE and AF) can be detected from

any one device. Figure 11 demonstrates a 16-bit word width by using two

IDT72420/72200/72210/72220/72230/72240s. Any word width can be

attainedbyaddingadditional IDT72420/72200/72210/72220/72230/72240s.

Figure 11. Block Diagram of 64 x 16, 256 x 16, 512 x 16, 1,024 x 16, 2,048 x 16, 4,096 x 16

Synchronous FIFO Used in a Width Expansion Configuration

WRITE CLOCK (WCLK)

READ CLOCK (RCLK)

READ ENABLE (

REN)

OUTPUT ENABLE (

OE)

FULL FLAG (

FF)

ALMOST-FULL (

AF)

EMPTY FLAG (

EF)

ALMOST-EMPTY(

AE)

IDT

72420

72200

72210

72220

72230

72240

RESET (

RS)

WRITE ENABLE (

WEN)

2680 drw 12

DATA IN (D)

WRITE CLOCK (WCLK)

16

8

8

RESET (

RS)

READ CLOCK (RCLK)

DATA OUT (Q)

8

16

WRITE ENABLE (

WEN)

FULL FLAG (

FF) #1

ALMOST-EMPTY (

AE)

EMPTY FLAG (

EF) #2

OUTPUT ENABLE (

OE)

READ ENABLE (

REN)

8

IDT

72420

72200

72210

72220

72230

72240

FULL FLAG (

FF) #2

EMPTY FLAG (

EF) #1

RESET (

RS)

IDT

72420

72200

72210

72220

72230

72240

2680 drw13

ALMOST-FULL (

AF)

OPERATING CONFIGURATIONS

SINGLE DEVICE CONFIGURATION - A single IDT72420/72200/72210/

72220/72230/72240 may be used when the application requirements are

for 64/256/512/1,024/2,048/4,096 words or less. See Figure 10.