A D V A N C E I N F O R M A T I O N
START
START
Protect all sectors:
PLSCNT = 1
PLSCNT = 1
The indicated portion
of the sector protect
algorithm must be
performed for all
unprotected sectors
prior to issuing the
first sector
RESET# = VID
RESET# = VID
Wait 1 µs
Wait 1 µs
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
A6 = 0, A1 = 1,
A0 = 0
Yes
Set up first sector
address
Sector Unprotect:
Wait 150 µs
Write 60h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
Verify Sector
Protect: Write 40h
to sector address
with A6 = 0,
Reset
PLSCNT = 1
Increment
PLSCNT
Wait 15 ms
A1 = 1, A0 = 0
Verify Sector
Unprotect: Write
40h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
Read from
sector address
with A6 = 0,
A1 = 1, A0 = 0
Increment
PLSCNT
No
No
PLSCNT
= 25?
Read from
sector address
with A6 = 1,
Data = 01h?
Yes
A1 = 1, A0 = 0
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
Sector Unprotect
Algorithm
from RESET#
Sector Protect
Algorithm
Sector Protect
complete
Write reset
command
Sector Unprotect
complete
Figure 1. In-system Sector Protection/Unprotection Algorithms
12
Am29SL400D
Rev. A Amend. +1 April 13, 2005
AMD [ AMD ]
