The TMS29F040 is a 524288 by 8-bit (4194304-bit), 5-V single-supply, programmable read-only memory that can be electrically erased and reprogrammed. This device is organized as eight independent 64K-byte sectors and is offered with access times between 60 ns and 120 ns. An on-chip state machine controls the program and erase operations. The embedded byte-program and sector / chip-erase functions are fully automatic. The command set is compatible with that of JEDEC 4M-bit EEPROMs. A suspend / resume feature allows access to unaltered memory sectors during a sector-erase operation. Data-protection of any sector combination is accomplished using a hardware sector-protection feature.