M28W320CT, M28W320CB

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Figure 14. Erase Flowchart and Pseudo Code

Note: 1. If an error is found, the Status Register must be cleared (CLRS instruction) before further P/E.C. operations.

Write 20h

Command

AI03541

Start

Write Block Address

& D0h Command

Read Status

Register

YES

NO

b7 = 1

YES

NO

b3 = 0

NO

b4, b5 = 0

VPP Invalid

Error (1)

Command

Sequence Error (1)

EE instruction:

– write 20h command

– write Block Address (A12-A20) &

command D0h

(memory enters read status state after

the EE instruction)

do:

– read status register (E or G must be

toggled) if PES instruction given execute

suspend erase loop

while b7 = 1

If b3 = 1, VPP invalid error:

– error handler

If b4, b5 = 1, Command sequence error:

– error handler

YES

NO

b5 = 0

Erase Error (1)

YES

NO

Suspend

Suspend

Loop

If b5 = 1, Erase error:

– error handler

End

YES

NO

b1 = 0

Erase to Protected

Block Error (1)

If b1 = 1, Erase to protected block error:

– error handler

YES