ESMT
F49L800UA/F49L800BA
Figure 16. In-System Sector Protect/Unprotect Algorithm (
= VID)
RESET
Start
Start
PLSCNT = 1
PLSCNT = 1
Protect all sector :
The indicated portion
of the sector protect
algorithm must be
performed for all
unprotected sectors
prior to issuing the
first sector
RESET = VID
RESET = VID
μ
Wait 1 s?
μ
Wait 1 s?
unprotect address
No
First W rite
No
Temporary Sector
Unprotect Mode
First W rite
Temporary Sector
Unprotect Mode
Cycle
=
60h?
Cycle
=
60h?
Yes
Yes
Set up sector
address
No
All sectors
protected?
Yes
Set up first
Sector Protect :
Write 60h to sector
address with
A6 = 0, A1 = 1,
A0 = 0
sector address
Sector Unprotect :
Write 60h to sector
address with
Wait 150 μ s?
A6 = 1, A1 = 1,
A0 = 0
Verify Sector
Protect : Write 40h
to sector address
with A6 = 0,
Reset
PLSCNT = 1
Wait 15 ms?
Increment
PLSCNT
A1 = 1, A0 = 0
Verify Sector
Unprotect : Write
40h to sector
address with
A6 = 1, A1 = 1,
A0 =0
Read from
sector address
with A6 = 0,
Increment
PLSCNT
A1 = 1, A0 = 0
No
No
PLSCNT = 25?
Data = 01h?
Yes
Read from
sector address
with A6 = 1,
Yes
A1 = 1, A0 =0
Device failed
Yes
Protect another
sector?
No
Set up
next sector
address
No
No
PLSCNT
= 1000?
Data = 00h?
Yes
Remove VID
from RESET
Yes
Device failed
No
Last sector
verified?
Write reset
command
Yes
Sector Protect
Algorithm
Sector Protect
complete
Sector Unprotect
Algorithm
Remove VID
from RESET
Write reset
command
Sector Protect
complete
Elite Semiconductor Memory Technology Inc.
Publication Date : Jan. 2008
Revision: 1.6 34/47
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
