L200BB55RD AMD [Advanced Micro Devices], L200BB55RD Datasheet - Page 15

• Manufacturer Part Number: L200BB55RD
• Description: 2 Megabit (256 K x 8-Bit/128 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

October 10, 2006 21521D6
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#
Set up sector
Verify Sector
Cycle = 60h?
Remove V
PLSCNT = 1
address with
with A6 = 0,
with A6 = 0,
Wait 150 µs
Data = 01h?
Write reset
Read from
First Write
command
Wait 1 μs
complete
address
Figure 1. In-System Sector Protect/Unprotect Algorithms
START
sector?
A0 = 0
Yes
Yes
No
ID
ID
Yes
PLSCNT = 1
Reset
D A T A S H E E T
Am29LV200B
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?
No
Yes
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
40h to sector
from RESET#
Verify Sector
address with
Cycle = 60h?
Remove V
PLSCNT = 1
address with
with A6 = 1,
Data = 00h?
Write reset
Wait 15 ms
Read from
First Write
Last sector
command
Wait 1 μs
All sectors
protected?
complete
address
verified?
START
A0 = 0
A0 = 0
Yes
Yes
Yes
Yes
ID
ID
No
No
Temporary Sector
Unprotect Mode
next sector
address
Set up
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