Functional Description

The Cypress CY14B256L is a fast static RAM with a nonvolatile element in each memory cell. The embedded nonvolatile elements incorporate QuantumTrap technology producing the world’s most reliable nonvolatile memory. The SRAM provides unlimited read and write cycles, while independent, nonvolatile data resides in the highly reliable QuantumTrap cell. Data transfers from the SRAM to the nonvolatile elements (the STORE operation) takes place automatically at power down. On power up, data is restored to the SRAM (the RECALL operation) from the nonvolatile memory. Both the STORE and RECALL operations are also available under software control. A hardware STORE is initiated with the HSB pin.

Features

■ 25 ns, 35 ns, and 45 ns access times

■ Pin compatible with STK14D88

■ Hands off automatic STORE on power down with only a small capacitor

■ STORE to QuantumTrap™ nonvolatile elements is initiated by software, hardware, or AutoStore™ on power down

■ RECALL to SRAM initiated by software or power up

■ Unlimited READ, WRITE, and RECALL cycles

■ 200,000 STORE cycles to QuantumTrap

■ 20 year data retention at 55°C

■ Single 3V +20, –10 operation

■ Commercial and industrial temperature

■ 32-pin (300 mil) SOIC and 48-pin (300 mil) SSOP packages

■ RoHS compliance