Description
The U631H16 has two separate modes of operation: SRAM mode and nonvolatile mode. In SRAM mode, the memory operates as an ordinary static RAM. In nonvolatile operation, data is transferred in parallel from SRAM to EEPROM or from EEPROM to SRAM. In this mode SRAM functions are disabled.
The U631H16 is a fast static RAM (25, 35, 45 ns), with a nonvolatile electrically erasable PROM (EEPROM) element incorporated in each static memory cell. The SRAM can be read and written an unlimited number of times, while independent nonvolatile data resides in EEPROM.

FEATUREs
• High-performance CMOS nonvolatile static RAM 2048 x 8 bits
• 25, 35 and 45 ns Access Times
• 12, 20 and 25 ns Output Enable Access Times
• Software STORE Initiation (STORE Cycle Time < 10 ms)
• Automatic STORE Timing
• 106 STORE cycles to EEPROM
• 100 years data retention in EEPROM
• Automatic RECALL on Power Up
• Software RECALL Initiation (RECALL Cycle Time < 20 μs)
• Unlimited RECALL cycles from EEPROM
• Unlimited Read and Write to SRAM
• Single 5 V ± 10 % Operation 
• Operating temperature ranges: 0 to 70 °C -40 to 85 °C
• QS 9000 Quality Standard
• ESD protection > 2000 V (MIL STD 883C M3015.7-HBM)
• RoHS compliance and Pb- free
• Packages: PDIP28 (600 mil)
                SOP24 (300 mil)