R
MX29LV160BT/BB
Figure 15. IN-SYSTEM CHIP UNPROTECTION ALGORITHM WITH RESET=VID
START
PLSCNT=1
RESET=VID
Wait 1us
No
No
Temporary Sector
Unprotect Mode
First Write
Cycle=60H ?
Yes
All sector
Protect all sectors
protected?
Yes
Set up first sector address
Sector unprotect :
write 60H with
A6=1, A1=1, A0=0
Wait 50ms
Verify sector unprotect
write 40H to sector address
with A6=1, A1=1, A0=0
Increment PLSCNT
Read from sector address
with A6=1, A1=1, A0=0
No
No
Set up next sector address
PLSCNT=1000?
Data=00H ?
Yes
Yes
Device failed
Yes
Last sector
verified?
No
Remove VID from RESET
Write reset command
Sector unprotect complete
P/N:PM1041
REV. 1.2, JUL. 01, 2004
41