Block protection
Figure 18. In-System Equipment Group Protect flowchart
M29W640FT, M29W640FB
START
n = 0
RP = V
ID
WRITE 60h
ADDRESS = GROUP ADDRESS
A0, A2, A3, A6 = V , A1 = V
IL
IH
WRITE 60h
ADDRESS = GROUP ADDRESS
A0, A2, A3, A6 = V , A1 = V
IL
Wait 100µs
WRITE 40h
IH
ADDRESS = GROUP ADDRESS
A0, A2, A3, A6 = V , A1 = V
IL
IH
Wait 4µs
READ DATA
ADDRESS = GROUP ADDRESS
A0, A2, A3, A6 = V , A1 = V
IL
IH
DATA
NO
=
01h
YES
RP = V
++n
= 25
NO
IH
YES
RP = V
ISSUE READ/RESET
COMMAND
IH
PASS
ISSUE READ/RESET
COMMAND
FAIL
AI11563
1. Block Protection Groups are shown in Appendix A, Tables 21 and 22.
2. RP can be either at VIH or at VID when using the In-System Technique to protect the Extended Block.
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NUMONYX [ NUMONYX B.V ]
