E S I
I
ES
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In-System Protection / Unprotection Method
START
COUNT = 1
RESET# = V
ID
Wait 1us
Protect all sectors:
The indicated por-
tion of the sector
protect algorithm
must be performed
for all unprotected
sectors prior to
issuing the first
sector unprotect
address
START
COUNT = 1
RESET# = V
ID
Wait 1us
Temporary Sector
Unprotect Mode
No
First Write
Cycle = 60h?
Yes
Set up sector
address
Sector Protect:
Write 60h to sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
Wait 150us
Verify Sector
Protect:
Write 40h to sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
Read from sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
First Write
Cycle = 60h?
Yes
No
All sectors
protected ?
Yes
Set up first sector
address
Sector Unpro-
tect:
Write 60h to sec-
tor address with
A6 = 1, A1 = 1,
No
Temporary Sector
Unprotect Mode
Increment
COUNT
Reset
COUNT = 1
Wait 15ms
Verify Sector
Unprotect:
Write 40h to sec-
tor address with
A6 = 1, A1 = 1,
A0 = 0
Read from sec-
tor address with
A6 = 1, A1 = 1,
A0 = 0
No
No
Increment
COUNT
Set up next
sector address
No
No
COUNT=25?
Yes
Device failed
Data = 01h?
Yes
Protect another
sector?
No
Remove V
ID
from RESET#
Write reset
command
Sector Protect
complete
Yes
COUNT
=1000?
Yes
Device failed
Data = 00h?
Yes
Last sector
verified?
Yes
Remove V
ID
from
RESET#
Write reset
command
Sector Unprotect
complete
No
Figure 2. In-System Sector
Protect Algorithm
Figure 3. In-System Sector
Unprotect Algorithm
ES29LV800D
13
Rev. 1D January 5, 2006
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
