PC
Am29F040 datasheet and PDF free download: http://www.chinaicmart.com/series-AM2/AM29F040.html
GENERAL DESCRIPTION The Am29F040 is a 4 Mbit, 5.0 Volt-only Flash memory organized as 512 Kbytes of 8 bits each. The Am29F040 is offered in a 32-pin package. This device is designed to be programmed in-system with the standard system 5.0 V V CCsupply. A 12.0 V V PP is not required for write or erase operations. The device can also be reprogrammed in standard EPROM programmers. The standard Am29F040 offers access times between 55 ns and 150 ns, allowing operation of high-speed microprocessors without wait states. To eliminate bus contention the device has separate chip enable (CE), write enable (WE) and output enable (OE) controls. The Am29F040 is entirely command set compatible with the JEDEC single-power-supply Flash standard. Commands are written to the command register using standard microprocessor write timings. Register contents serve as input to an internal state machine which controls the erase and programming circuitry. Write cycles also internally latch addresses and data needed for the programming and erase operations.Reading data out of the device is similar to reading from 12.0 Volt Flash or EPROM devices. The Am29F040 is programmed by executing the program command sequence. This will invoke the Embedded Program Algorithm which is an internal algorithm that automatically times the program pulse widths and verifies proper cell margin. Typically, each sector can be programmed and verified in less than one second. Erase is accomplished by executing the erase command sequence. This will invoke the Embedded Erase Algorithm which is an internal algorithm that automatically preprograms the array if it is not already programmed before executing the erase operation. During erase, the device automatically times the erase pulse widths and verifies proper cell margin.