7

IDT72V201/72V211/72V221/72V231/72V241/72V251 3.3V CMOS SyncFIFO™

256 x 9, 512 x 9, 1,024 x 9, 2,048 x 9, 4,096 x 9 and 8,192 x 9

COMMERCIALANDINDUSTRIAL

TEMPERATURERANGES

OUTPUTS:

FULL FLAG (FF)

TheFullFlag(FF)willgoLOW,inhibitingfurtherwriteoperation,whenthe

device is full. If no reads are performed after Reset (RS), the Full Flag (FF)

willgoLOWafter256writesfortheIDT72V201,512writesfortheIDT72V211,

1,024writesfortheIDT72V221,2,048writesfortheIDT72V231,4,096writes

for the IDT72V241 and 8,192 writes for the IDT72V251.

The Full Flag (FF) is synchronized with respect to the LOW-to-HIGH

transitionoftheWriteClock(WCLK).

EMPTY FLAG (EF)

TheEmptyFlag(EF)willgoLOW,inhibitingfurtherreadoperations,when

the read pointer is equal to the write pointer, indicating the device is empty.

The Empty Flag (EF) is synchronized with respect to the LOW-to-HIGH

transition of the Read Clock (RCLK).

PROGRAMMABLE ALMOST-FULL FLAG (PAF)

The Programmable Almost-Full flag (PAF) will go LOW when the FIFO

reachesthealmost-fullcondition.IfnoreadsareperformedafterReset(RS),

theProgrammableAlmost-Fullflag(PAF)willgoLOWafter (256-m)writesfor

the IDT72V201, (512-m) writes for the IDT72V211, (1,024-m) writes for the

IDT72V221, (2,048-m) writes for the IDT72V231, (4,096-m) writes for the

IDT72V241and(8,192-m)writesfortheIDT72V251. Theoffset“m”isdefined

intheFullOffsetregisters.

Ifthereisnofulloffsetspecified,theProgrammableAlmost-Fullflag(PAF)

will go LOW at Full-7 words.

TheProgrammableAlmost-Fullflag(PAF)issynchronizedwithrespectto

theLOW-to-HIGHtransitionoftheWriteClock(WCLK).

PROGRAMMABLEALMOST-EMPTYFLAG(PAE)

TheProgrammableAlmost-Emptyflag(PAE)willgoLOWwhentheread

pointer is "n+1" locations less than the write pointer. The offset "n" is defined

in the Empty Offset registers. If no reads are performed after Reset the

Programmable Almost-Empty flag (PAE) will go HIGH after "n+1" for the

IDT72V201/72V211/72V221/72V231/72V241/72V251.

Ifthereisnoemptyoffsetspecified,theProgrammableAlmost-Emptyflag

(PAE) will go LOW at Empty+7 words.

TheProgrammableAlmost-Emptyflag(PAE)issynchronizedwithrespect

to the LOW-to-HIGH transition of the Read Clock (RCLK).

Data outputs for a 9-bit wide data.

NUMBER OF WORDS IN FIFO

IDT72V201

IDT72V211

IDT72V221

FF

PAF

PAE

EF

00

0

H

H

L

L

HH

L

H

(n+1)to(256-(m+1))

(n+1)to(512-(m+1))

(n+1)to(1,024-(m+1))

HHHH

H

L

H

H

256

512

1,024

L

L

H

H

NUMBER OF WORDS IN FIFO

IDT72V231

IDT72V241

IDT72V251

FF

PAF

PAE

EF

000

H

H

L

L

HH

L

H

(n+1)to(2,048-(m+1))

(n+1)to(4,096-(m+1))

(n+1)to(8,192-(m+1))

HHHH

H

L

H

H

2,048

4,096

8,192

L

L

H

H

NOTES:

1. n = Empty Offset (n = 7 default value)

2. m = Full Offset (m = 7 default value)

TABLE 1 — STATUS FLAGS