P R E L I M I N A R Y
START
PLSCNT = 1
RESET# = V
ID
Wait 1
µs
Protect all sectors:
The indicated portion
of the sector protect
algorithm must be
performed for all
unprotected sectors
prior to issuing the
first sector
unprotect address
START
PLSCNT = 1
RESET# = V
ID
Wait 1
µs
Temporary Sector
Unprotect Mode
No
First Write
Cycle = 60h?
Yes
Set up sector
address
Sector Protect:
Write 60h to sector
address with
A6 = 0, A1 = 1,
A0 = 0
Wait 150 µs
Verify Sector
Protect: Write 40h
to sector address
with A6 = 0,
A1 = 1, A0 = 0
Read from
sector address
with A6 = 0,
A1 = 1, A0 = 0
No
No
First Write
Cycle = 60h?
Yes
All sectors
protected?
Yes
Set up first sector
address
Sector Unprotect:
Write 60h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
Temporary Sector
Unprotect Mode
Increment
PLSCNT
Reset
PLSCNT = 1
Wait 15 ms
Verify Sector
Unprotect: Write
40h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
No
No
PLSCNT
= 25?
Yes
Data = 01h?
Increment
PLSCNT
Yes
No
Yes
No
Read from
sector address
with A6 = 1,
A1 = 1, A0 = 0
Set up
next sector
address
Device failed
Protect another
sector?
No
Remove V
ID
from RESET#
PLSCNT
= 1000?
Yes
Data = 00h?
Yes
Device failed
Write reset
command
Last sector
verified?
Yes
No
Sector Protect
Algorithm
Sector Protect
complete
Sector Unprotect
Algorithm
Remove V
ID
from RESET#
Write reset
command
Sector Unprotect
complete
Note:
The term “sector” in the figure applies to both sectors and sector blocks.
Figure 2.
In-System Sector/Sector Block Protect and Unprotect Algorithms
September 5, 2002
Am41DL32x8G
23
AMD [ ADVANCED MICRO DEVICES ]
