The CAT28C257 is a fast, low power, 5V-only CMOS Parallel E2PROM organized as 32K x 8-bits. It requires a simple interface for in-system programming. On-chip address and data latches, self-timed write cycle with autoclear and VCC power up/down write protection eliminate additional timing and protection hardware. DATA Polling and Toggle status bits signal the start and end of the selftimed write cycle. Additionally, the CAT28C257 features hardware and software write protection.