S29AL004D SPANSION, S29AL004D Datasheet - Page 19

• Manufacturer Part Number: S29AL004D
• Description: 4 Megabit (512 Kx 8-Bit/256 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
• Manufacturer: SPANSION

February 18, 2005 S29AL004D_00_A1
Sector Protect
Temporary Sector
Unprotect Mode
Device failed
Algorithm
Increment
PLSCNT
PLSCNT
= 25?
No
Yes
No
Figure 2. In-System Sector Protect/Sector Unprotect Algorithms
No
Write 60h to sector
Protect: Write 40h
to sector address
A6 = 0, A1 = 1,
Sector Protect:
A1 = 1, A0 = 0
A1 = 1, A0 = 0
Protect another
sector address
RESET# = V
Sector Protect
Verify Sector
Set up sector
with A6 = 0,
with A6 = 0,
from RESET#
Cycle = 60h?
address with
Remove V
Data = 01h?
PLSCNT = 1
Wait 150 µs
Write reset
Read from
First Write
command
A d v a n c e
Wait 1 µs
complete
address
A0 = 0
sector?
START
No
Yes
Yes
ID
ID
Yes
PLSCNT = 1
I n f o r m a t i o n
Reset
S29AL004D
The indicated portion
unprotected sectors
of the sector protect
prior to issuing the
Protect all sectors:
unprotect address
algorithm must be
performed for all
Sector Unprotect
first sector
Algorithm
Device failed
Increment
= 1000?
PLSCNT
PLSCNT
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,
A1 = 1, A0 = 0
sector address
RESET# = V
40h to sector
Verify Sector
address with
with A6 = 1,
from RESET#
Cycle = 60h?
address with
Remove V
Data = 00h?
PLSCNT = 1
Write reset
Wait 15 ms
Read from
First Write
Last sector
protected?
command
Wait 1 µs
All sectors
complete
verified?
address
A0 = 0
A0 = 0
START
Yes
Yes
Yes
Yes
ID
ID
No
No
Temporary Sector
Unprotect Mode
next sector
address
Set up
17