M93S66, M93S56 M93S46 4Kbit, 2Kbit and 1Kbit (16-bit wide) MICROWIRE Serial Access EEPROM with Block Protection features industry standard MICROWIRE Bus, single supply voltage, single organization, programming instructions, self-timed programming cycle with auto-erase, user defined write protected area, page write mode, ready/busy signal during programming, speed, sequential read operation, enhanced ESD/Latch-Up Behavior, more than 1 million erase/write cycles, more than 40 year data retention.