This description applies specifically to the M29F 16Mb (2 Meg x 8 or 1 Meg x 16) nonvolatile memory device, but also applies to lower densities. The device enables READ, ERASE, and PROGRAM operations using a single, low-voltage (4.5–5.5V) supply. On power-up, the device defaults to read mode and can be read in the same way as a ROM or EPROM.
The device is divided into blocks that can be erased independently, preserving valid data while old data is erased. Each block can be protected independently to prevent accidental PROGRAM or ERASE operations from modifying the memory. PROGRAM and ERASE commands are written to the command interface. An on-chip program/erase controller simplifies the process of programming or erasing the device by managing the operations required to update the memory contents.
The end of a PROGRAM or ERASE operation can be detected and any error conditions identified. The command set required to control the memory is consistent with JEDEC standards. The blocks are asymmetrically arranged. The first or last 64KB have been divided into four additional blocks. The 16KB boot block can be used for small initialization code to start the microprocessor. The two 8KB parameter blocks can be used for parameter storage. The remaining 32KB is a small main block where the application may be stored. CE#, OE#, and WE# control the bus operation of the memory. They enable simple connection to most microprocessors, often without additional logic. Devices are offered in 48-pin TSOP (12mm x 20mm) and 44-pin small-outline packages. The device is supplied with all the bits erased (set to 1).