AM29DL640G65 AMD [Advanced Micro Devices], AM29DL640G65 Datasheet - Page 18

• Manufacturer Part Number: AM29DL640G65
• Description: 64 Megabit (8 M x 8-Bit/4 M x 16-Bit) CMOS 3.0 Volt-only, Simultaneous Read/Write Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

18
Sector Protect
Temporary Sector
Unprotect Mode
Algorithm
Device failed
Increment
PLSCNT
PLSCNT
= 25?
No
Yes
No
No
Write 60h to sector
Protect: Write 40h
to sector address
A6 = 0, A1 = 1,
Protect another
Sector Protect:
sector address
RESET# = V
A1 = 1, A0 = 0
A1 = 1, A0 = 0
Sector Protect
from RESET#
Verify Sector
Set up sector
Cycle = 60h?
Remove V
PLSCNT = 1
address with
with A6 = 0,
with A6 = 0,
Data = 01h?
Wait 150 µs
Write reset
Read from
First Write
command
Wait 1 s
complete
address
START
Figure 2. In-System Sector Protect/Unprotect Algorithms
sector?
A0 = 0
Yes
Yes
No
ID
ID
Yes
PLSCNT = 1
P R E L I M I N A R Y
Reset
Am29DL640G
The indicated portion
unprotected sectors
Protect all sectors:
of the sector protect
prior to issuing the
unprotect address
algorithm must be
performed for all
Sector Unprotect
first sector
Algorithm
Device failed
Increment
PLSCNT
PLSCNT
= 1000?
Yes
No
No
No
Write 60h to sector
Set up first sector
Sector Unprotect:
Unprotect: Write
Sector Unprotect
A6 = 1, A1 = 1,
A6 = 1, A1 = 1,
sector address
RESET# = V
A1 = 1, A0 = 0
from RESET#
Verify Sector
40h to sector
address with
Cycle = 60h?
Remove V
PLSCNT = 1
address with
with A6 = 1,
Data = 00h?
Wait 15 ms
Write reset
Read from
First Write
Last sector
protected?
command
Wait 1 s
All sectors
complete
address
verified?
START
A0 = 0
A0 = 0
Yes
Yes
Yes
Yes
ID
ID
No
No
Temporary Sector
Unprotect Mode
June 7, 2002
next sector
address
Set up