9

Commercial Temperature Range

IDT72V81/72V82/72V83/72V84/72V85

TABLE II—RESET AND FIRST LOAD TRUTH TABLE

Depth Expansion/Compound Expansion Mode

Inputs

Internal Status

Outputs

Mode

RS

RS

RS

RS

RS

FL

FL

FL

FL

FL

XI

XI

XI

XI

XI

Read Pointer

Write Pointer

EF

EF

EF

EF

EF

FF

FF

FF

FF

FF

Reset First Device

0

0

(1)

LocationZero

LocationZero

0

1

Reset All Other Devices

0

1

(1)

LocationZero

LocationZero

0

1

Read/Write

1

X

(1)

X

X

X

X

NOTE:

1.

XI is connected to XO of previous device. See Figure 14. RS = Reset Input, FL/RT = First Load/Retransmit, EF = Empty Flag Output, FF = Full Flag Output,

XI = Expan-

sion Input,

HF = Half-Full Flag Output

TABLE I—RESET AND RETRANSMIT

Single Device Configuration/Width Expansion Mode

Inputs

Internal Status

Outputs

Mode

RS

RS

RS

RS

RS

RT

RT

RT

RT

RT

XI

XI

XI

XI

XI

Read Pointer

Write Pointer

EF

EF

EF

EF

EF

FF

FF

FF

FF

FF

HF

HF

HF

HF

HF

Reset

0

X

0

LocationZero

LocationZero

0

1

1

Retransmit

1

0

0

LocationZero

Unchanged

X

X

X

Read/Write

1

1

0

Increment

(1)

Increment

(1)

XX

X

NOTE:

1. Pointer will increment if flag is High.

Figure 14. Block Diagram of 2,048 x 9, 4,096 x 9, 8,192 x 9, 16,384 x 9 and 32,768 x 9 FIFO Memory (Depth Expansion)

D

W

FFB

EFB

FLB

XOB

RSA

FULL

EMPTY

R

9

9

99

XIB

9

Q

FFA

EFA

FLA

XOA

XIA

FFB

EFB

FLB

XIB

3966 drw 16

XOA

FIFO A

FIFO B

FIFO A

FIFO B

XIA

XOB

EFA

FLA

FFA

72V81/72V82

72V83/72V84

72V85

72V81/72V82

72V83/72V84

72V85