AM42DL6404G Datasheet, PDF (21/61 Pages) Advanced Micro Devices – 64 Megabit (8 M x 8-Bit/4 M x 16-Bit) CMOS 3.0 Volt-only, Simultaneous Operation Flash Memory and 4 Mbit (256 K x 16-Bit) Static RAM

PRELIMINARY
START
PLSCNT = 1
RESET# = V_ID
Wait 1 µs
Temporary Sector
Unprotect Mode
No _{First Write}
Cycle = 60h?
Yes
Set up sector
address
Sector Protect:
Write 60h to sector
address with
A6 = 0, A1 = 1,
A0 = 0
Wait 150 µs
Increment
PLSCNT
No
PLSCNT
= 25?
Yes
Device failed
Verify Sector
Protect: Write 40h
to sector address
with A6 = 0,
A1 = 1, A0 = 0
Read from
sector address
with A6 = 0,
A1 = 1, A0 = 0
Reset
PLSCNT = 1
No
Data = 01h?
Yes
Yes
Protect another
sector?
No
Remove V_ID
from RESET#
Sector Protect
Algorithm
Write reset
command
Sector Protect
complete
Protect all sectors:
The indicated portion
of the sector protect
algorithm must be
performed for all
unprotected sectors
prior to issuing the
first sector
unprotect address
Increment
PLSCNT
START
PLSCNT = 1
RESET# = V_ID
Wait 1 µs
First Write ^No _{Temporary Sector}
Cycle = 60h?
Unprotect Mode
Yes
No _{All sectors}
protected?
Yes
Set up first sector
address
Sector Unprotect:
Write 60h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
Wait 15 ms
Verify Sector
Unprotect: Write
40h to sector
address with
A6 = 1, A1 = 1,
A0 = 0
No
PLSCNT
= 1000?
Yes
Read from
sector address
with A6 = 1,
A1 = 1, A0 = 0
No
Data = 00h?
Yes
Set up
next sector
address
Device failed
Sector Unprotect
Algorithm
Last sector ^No
verified?
Yes
Remove V_ID
from RESET#
Write reset
command
Sector Unprotect
complete
Figure 2. In-System Sector Protect/Unprotect Algorithms
20
Am42DL6404G
March 20, 2002