COTS PEM
BOOT SECTOR FLASH
Austin Semiconductor, Inc.
Figure 2. In-System Sector Protect/Unprotect Algorithms
AS29LV016J
START
Protect all sectors:
PLSCNT = 1
START
The indicated portion
of the sector group protect
algorithm must be
performed for all
unprotected sector groups
prior to issuing the
RESET# = VID
Wait 1 μs
PLSCNT = 1
RESET# = VID
first sector group
unprotect address
Wait 1 μs
No
First Write
Temporary Sector
Group Unprotect Mode
Cycle = 60h?
No
First Write
Cycle = 60h?
Temporary Sector
Group Unprotect Mode
Yes
No
All sectors
protected?
Yes
Set up sector
group address
Yes
Set up first sector
group address
Sector Group Protect:
Write 60h to sector group
address with
A6 = 0,
A3 = A2 = 0,
A1 = 1, A0 = 0
Sector Group Unprotect:
Write 60h to sector
address with
A6 = 1,
A3 = A2 = 0,
A1 = 1, A0 = 0
Wait 150 μs
Verify Sector Group
Protect: Write 40h
Wait 1.5 ms
to sector group address
with A6 = 0,
Verify Sector Group
Unprotect: Write
40h to sector group
address with
A3 = A2 = 0,
A1 = 1, A0 = 0
Increment
PLSCNT
Reset
PLSCNT = 1
A6 = 1,
A3 = A2 = 0,
A1 = 1, A0 = 0
Read from
sector group address
with A6 = 0,
Increment
PLSCNT
A3 = A2 = 0,
A1 = 1, A0 = 0
Read from
No
sector group address
with A6 = 1,
A3 = A2 = 0,
A1 = 1, A0 = 0
No
PLSCNT
= 25?
Data = 01h?
No
Set up
next sector group
address
Yes
No
Yes
PLSCNT
= 1000?
Data = 00h?
Yes
Protect another
sector group?
Device failed
Yes
Yes
No
Last sector
No
Device failed
group verified?
Remove VID
from RESET#
Yes
Write reset
command
Remove VID
from RESET#
Sector Group
Unprotect Algorithm
Sector Group
Protect Algorithm
Sector Group
Protect complete
Write reset
command
Sector Group
Unprotect complete
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
AS29LV016J
Rev. 0.0 02/09
13
AUSTIN [ AUSTIN SEMICONDUCTOR ]
