SN54ABT7819

512

× 18 × 2

CLOCKED BIDIRECTIONAL FIRST-IN, FIRST-OUT MEMORY

SGBS305D – AUGUST 1994 – REVISED APRIL 1998

8

POST OFFICE BOX 655303

Terminal Functions (Continued)

TERMINAL

NAME

I/O

DESCRIPTION

WENA

I

Port-A write enable. A high level on WENA enables data on A0–A17 to be written into FIFOA–B on the low-to-high

transition of CLKA when W/RA is high, CSA is low, and IRA is high.

WENB

I

Port-B write enable. A high level on WENB enables data on B0–B17 to be written into FIFOB–A on the low-to-high

transition of CLKB when W/RB is high, CSB is low, and IRB is high.

W/RA

I

Port-A write/read select. A high on W/RA enables A0–A17 data to be written to FIFOA–B on a low-to-high transition

of CLKA when WENA is high, CSA is low, and IRA is high. A low on W/RA enables data to be read from FIFOB–A

on a low-to-high transition of CLKA when RENA is high, CSA is low, and ORA is high. The A0–A17 outputs are in the

high-impedance state when W/RA is high.

W/RB

I

Port-B write/read select. A high on W/RB enables B0–B17 data to be written to FIFOB–A on a low-to-high transition

of CLKB when WENB is high, CSB is low, and IRB is high. A low on W/RB enables data to be read from FIFOA–B

on a low-to-high transition of CLKB when RENB is high, CSB is low, and ORB is high. The B0–B17 outputs are in the

high-impedance state when W/RB is high.

AF/AEA

HFA

ORB

IRA

RSTA

CLKB

CLKA

4

3

2

1

2

1

4

3

2

1

† FIFOB–A is reset in the same manner.