am42bds6408h Meet Spansion Inc., am42bds6408h Datasheet - Page 23

• Manufacturer Part Number: am42bds6408h
• Description: Cmos 1.8 Volt-only Simultaneous Read/write, Burst Mode Flash Memory, And 8 Mbit 512 K X 16-bit Sram
• Manufacturer: Meet Spansion Inc.

October 23, 2003
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
Protect another
Sector Protect:
sector address
RESET# = V
Sector Protect
Verify Sector
with A7
with A7
from RESET#
Set up sector
Cycle = 60h?
Remove V
PLSCNT = 1
address with
Data = 01h?
Wait 150 µs
Write reset
Read from
First Write
00000010
00000010
00000010
command
Wait 1 µs
complete
A7
address
START
sector?
–
A0 =
–
–
Yes
Yes
No
A0 =
A0 =
ID
A D V A N C E
ID
Figure 2. In-System Sector Protection/
Yes
Sector Unprotection Algorithms
PLSCNT = 1
Reset
Am42BDS6408H
I N F O R M A T I O N
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
sector address
RESET# = V
40h to sector
from RESET#
Verify Sector
address with
with A7
Cycle = 60h?
PLSCNT = 1
address with
Remove V
Data = 00h?
Write reset
Wait 15 ms
Read from
Last sector
First Write
01000010
00000010
00000010
All sectors
protected?
command
Wait 1 µs
A7
A7
complete
verified?
address
START
–
–
A0 =
A0 =
–
Yes
Yes
A0 =
Yes
Yes
ID
ID
No
No
Temporary Sector
Unprotect Mode
next sector
address
Set up
21