MX29F200T/B
SECTOR UNPROTECTION ALGORITHM FOR SYSTEM WITHOUT 12V
START
Protect All Sectors
PLSCNT=1
Write "unlock for sector protect/unprotect"
Command (Table 1)
Set OE=A9=VIH
CE=VIL,A6=1
Activate WE Pulse to start
Data don't care
No
Toggle bit checking
DQ6 not Toggled
Increment
PLSCNT
Yes
Set OE=CE=VIL
A9=VIH,A1=1
Set Up First Sector Addr
Read Data from Device
No
No
Data=00H?
Yes
Increment
PLSCNT=1000?
Sector Addr
Yes
Device Failed
No
All sectors have
been verified?
Yes
Write Reset Command
Chip Unprotect
Complete
* It is recommended before unprotect the whole chip, all sectors should be protected in advance.
P/N:PM0549
REV. 1.3 , DEC. 24, 2001
39