The SST31LF021/021E devices are a 256K x8 CMOS flash memory bank combined with a 128K x8 or 32K x8 CMOS SRAM memory bank manufactured with SST's proprietary, high performance SuperFlash technology. Two pinout standards are available for these devices. The SST31LF021 conform to JEDEC standard flash pinouts and the SST31LF021E conforms to standard EPROM pinouts. The SST31LF021/021E devices write (SRAM or flash) with a 3.0-3.6V power supply. The monolithic SST31LF021/021E devices conform to Software Data Protect (SDP) commands for x8 EEPROMs.