Preliminary W27C4096

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FUNCTIONAL DESCRIPTION

Read Mode

Like conventional UVEPROMs, the W27C4096 has two control functions, both of which produce data

at the outputs. CE is for power control and chip select. OE controls the output buffer to gate data to

Erase Mode

The erase operation is the only way to change data from "0" to "1." Unlike conventional UVEPROMs,

which use ultraviolet light to erase the contents of the entire chip (a procedure that requires up to half

an hour), the W27C4096 uses electrical erasure. Generally, the chip can be erased within 100 mS by

using an EPROM writer with a special erase algorithm.

Erase Verify Mode

After an erase operation, all of the words in the chip must be verified to check whether they have

been successfully erased to "1" or not. The erase verify mode automatically ensures a substantial

OE low.

Program Mode

Programming is performed exactly as it is in conventional UVEPROMs, and programming is the only

pins equal the desired inputs.

Program Verify Mode

All of the words in the chip must be verified to check whether they have been successfully

programmed with the desired data or not. Hence, after each word is programmed, a program verify

operation should be performed. The program verify mode automatically ensures a substantial

Erase/Program Inhibit

Erase or program inhibit mode allows parallel erasing or programming of multiple chips with different

common inputs.