DESCRIPTION
The Simtek STK12C68 is a fast static RAMwith a nonvolatile element incorporated in each static
memory cell. The SRAMcan be read and written an unlimited number of times, while independent, nonvolatile data resides in Nonvolatile Elements. Data transfers from the SRAMto the Nonvolatile Elements (the STOREoperation) can take place automatically on power down. A 68µF or larger capacitor tied from VCAPto ground guarantees the  STOREoperation, regardless of power-down slew rate or loss of power from “hot swapping”. Transfers from the Nonvolatile Elements to the SRAM(the RECALLoperation) take place automatically on restoration of power. Initiation of STORE and RECALLcycles can also be soft ware controlled by entering specific read sequences. A hardware STOREmay be initiated with the HSB pin.

FEATURES
• 25ns, 35ns, 45ns and 55ns Access Times
• “Hands-off” Automatic STOREwith External 68µF Capacitor on Power Down
• STOREto Nonvolatile Elements Initiated by Hardware, Software or AutoStore™ on Power Down
• RECALLto SRAM Initiated by Software or Power Restore
• 10mA Typical ICC at 200ns Cycle Time
• Unlimited READ, WRITE and RECALLCycles
• 1,000,000 STORECycles to Nonvolatile Elements (Commercial/Industrial)
• 100-Year Data Retention in Nonvolatile Elements (Commercial/Industrial)
• Commercial, Industrial and Military Temperatures
• 28-Pin SOIC, DIP and LCC Packages