Block protection
M29W800DT, M29W800DB
Figure 21. In-system equipment chip unprotect flowchart
START
PROTECT ALL BLOCKS
n = 0
CURRENT BLOCK = 0
RP = V
ID
WRITE 60h
ANY ADDRESS WITH
A0 = V , A1 = V , A6 = V
IL
IH
IH
IH
WRITE 60h
ANY ADDRESS WITH
A0 = V , A1 = V , A6 = V
IL
IH
Wait 10ms
WRITE 40h
ADDRESS = CURRENT BLOCK ADDRESS
A0 = V , A1 = V , A6 = V
IL
IH
IH
Wait 4µs
INCREMENT
CURRENT BLOCK
READ DATA
ADDRESS = CURRENT BLOCK ADDRESS
A0 = V , A1 = V , A6 = V
IL
IH
IH
DATA
NO
YES
=
00h
++n
= 1000
NO
NO
LAST
BLOCK
YES
RP = V
YES
RP = V
IH
IH
ISSUE READ/RESET
COMMAND
ISSUE READ/RESET
COMMAND
PASS
FAIL
AI03472
50/52