ISSUE 4.2:November1998
MFM8126S-70/90/12
Sector Unprotect Algorithm
START
Set Vcc=5.0V
Protect All Sectors
PLSCNT = 1
Set Up Sector
Unprotect Mode
A12 = A7 = VIH , A6 = VIL
Set Vcc=5.0V
Set
OE = CS = A9 = VID
Activate WE Pulse
Time Out 10ms
Set OE = CS= VIL
Remove VID from A9
Increment
PLSCNT
Set Vcc=4.25V
Write Autoselect
Command Sequence
Set Up Sector Addr SA0
Set A1=1, A0=0
Read Data
from Device
No
Data
=00H
?
No
PLSCNT
=1000
?
Write Reset
Command
Increment
Sector Addr
Yes
Sector
Addr = SA7
?
Device
Failed
No
Yes
Set Vcc=5.0V
Write Reset
Command
Sector Unprotect
Completed
NOTES:
SA0 = Sector Addr for intial sector
SA7 = Sector Addr to last sector
22
MOSAIC [ MOSAIC ]
