M29W400DT Datasheet, PDF (45/48 Pages) STMicroelectronics – 4 Mbit (512Kb x8 or 256Kb x16, Boot Block) 3V Supply Flash Memory

M29W400DT, M29W400DB
Figure 21. In-system equipment block protect flowchart
START
n=0
RP = VID
WRITE 60h
ADDRESS = BLOCK ADDRESS
A0 = VIL, A1 = VIH, A6 = VIL
WRITE 60h
ADDRESS = BLOCK ADDRESS
A0 = VIL, A1 = VIH, A6 = VIL
Wait 100 µs
WRITE 40h
ADDRESS = BLOCK ADDRESS
A0 = VIL, A1 = VIH, A6 = VIL
Wait 4 µs
READ DATA
ADDRESS = BLOCK ADDRESS
A0 = VIL, A1 = VIH, A6 = VIL
DATA NO
=
01h
YES
RP = VIH
ISSUE READ/RESET
COMMAND
PASS
++n NO
= 25
YES
RP = VIH
ISSUE READ/RESET
COMMAND
FAIL
Block protection
AI03471
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