Break Locked MCU W77E51 Eeprom Memory and extract its heximal out from it is a commonly requirement especially for those repairing companies with some obselete devices which use microcontroller W77E51, hereby we would like to introduce the composition of W77E51 on chip ROM:

The W77E51 has several modes to program the on-chip Flash EPROM. All these operations are configured by the pins RST, ALE, PSEN , A9CTRL(P3.0), A13CTRL(P3.1), A14CTRL(P3.2), OECTRL(P3.3), CE (P3.6), OE (P3.7), A0(P1.0) and VPP( EA ). Moreover, the A15A0(P2.7P2.0, P1.7P1.0) and the D7D0(P0.7P0.0) serve as the address and data bus respectively for these operations.

Read Operation
This operation is supported for customer to read their code and the Security bits. The data will not be valid if the Lock bit is programmed to low when Break Locked MCU W77E51 Eeprom Memory.

Output Disable Condition
When the OE is set to high, no data output appears on the D7..D0.

Program Operation
This operation is used to program the data to ROM and the security bits. Program operation is done when the VPP is reach to VCP (12.5V) level, CE set to low, and OE set to high.

Program Verify Operation
All the programming data must be checked after program operations. This operation should be performed after each byte is programmed; it will ensure a substantial program margin.

Erase Operation
An erase operation is the only way to change data from 0 to 1. This operation will erase all the ROM cells and the security bits from 0 to 1. This erase operation is done when the VPP is reach to VEP level, CE set to low, and OE set to high after Break Locked MCU W77E51 Eeprom Memory.

Erase Verify Operation
After an erase operation, all of the bytes in the chip must be verified to check whether they have been successfully erased to 1 or not. The erase verify operation automatically ensures a substantial erase margin. This operation will be done after the erase operation if VPP = VEP (14.5V), CE is high and  OE is low if BREAK IC.

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