Renesas Electronics SRAM Memory Chip, 71321SA55JG- 32kbit

The Renesas Electronics 71321 is a high-speed 2K x 8 Dual-Port Static RAM with internal interrupt logic for interprocessor communications. It is designed to be used as a stand-alone 8-bit Dual-Port RAM or as a "MASTER" Dual-Port RAM together with the 71421 "SLAVE" Dual-Port in 16-bit-or-more word width systems which would result in full-speed, error free operation without the need for additional discrete logic.

True Dual-Ported memory cells which allow simultaneous access of the same memory location
Two INT flags for port-to-port communications
Easily expands data bus width to 16-or more- bits using SLAVE 71421
On-chip port arbitration logic
BUSY output flag
Fully asynchronous operation from either port
Battery backup operation – 2V data retention (LA only)
TTL-compatible, single 5V ±10% power supply
Available in 52-Pin PLCC and TQFP, 64-Pin TQFP and STQFP packages
Industrial temperature range (-40C to +85C) is available