D A T A S H E E T
START
START
Protect all sectors:
The indicated portion
of the sector protect
algorithm must be
performed for all
unprotected sectors
prior to issuing the
first sector
PLSCNT = 1
PLSCNT = 1
RESET# = VID
RESET# = VID
Wait 1 ms
Wait 1 ms
unprotect address
No
First Write
Cycle = 60h?
No
First Write
Cycle = 60h?
Temporary Sector
Unprotect Mode
Temporary Sector
Unprotect Mode
Yes
Yes
Set up sector
address
No
All sectors
protected?
Sector Protect:
Write 60h to sector
address with
Yes
Set up first sector
address
A7–A0 =
00000010
Sector Unprotect:
Write 60h to sector
address with
A7:A0 =
Wait 150 µs
Verify Sector
Protect: Write 40h
to sector address
01000010
Reset
PLSCNT = 1
Increment
PLSCNT
with A7–A0 =
00000010
Wait 1.5 ms
Verify Sector
Unprotect: Write
40h to sector
address with
Read from
sector address
with A7–A0 =
00000010
Increment
PLSCNT
A7–A0 =
00000010
No
No
PLSCNT
= 25?
Read from
sector address
Data = 01h?
Yes
with A7–A0 =
00000010
No
Yes
Set up
next sector
address
Yes
No
PLSCNT
= 1000?
Protect another
sector?
Data = 00h?
Yes
Device failed
No
Yes
Remove VID
from RESET#
No
Last sector
verified?
Device failed
Write reset
command
Yes
Remove VID
from RESET#
Sector Unprotect
Algorithm
Sector Protect
Algorithm
Sector Protect
complete
Write reset
command
Sector Unprotect
complete
Figure 2. In-System Sector Protection/
Sector Unprotection Algorithms
22
Am29BDS128H/Am29BDS640H
27024B3 May 10, 2006