TMS29LF040

The TMS29LF040 and TMS29VF040 are 524288 by 8-bit (4194304-bit), low-voltage, single-supply,programmable read-only memories that can be erased electrically and reprogrammed. These devices are organized as eight independent 64K-byte sectors and are offered with access times between 80 ns and 150 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.

Device operations are selected by writing JEDEC-standard commands into the command register using standard microprocessor-write timings. The command register acts as input to an internal state machine that interprets the commands, controls the erase and programming operations, and outputs the status of the device, the data stored in the device, and the device algorithm-selection code. On initial power-up operation, the device defaults to the read mode.

The TMS29xF040 is offered in a 32-pin 8 x 14 mm thin small-outline package (DBW suffix), a 32-pin 8 x 20 mm thin small-outline package (DD suffix), and a 32-pin plastic leaded chip carrier (FM suffix) using 1.27 mm (50-mil) lead pitch