M50FW002

34/39

Figure 18. Block Erase Flowchart and Pseudo Code

Note: 1. If an error is found, the Status Register must be cleared before further Program/Erase Controller operations.

Write 20h

AI05433

Start

Write Block Address

& D0h

Read Status

Register

YES

NO

b7 = 1

YES

NO

b3 = 0

NO

b4, b5 = 0

VPP Invalid

Error (1)

Command

Sequence Error (1)

Erase command:

– write 20h

– write Block Address & D0h

(memory enters read Status Register after

the Erase command)

do:

– read Status Register

– if Program/Erase Suspend command

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

FWH

Interface

Only