E S I
E S I
ADVANCED INFORMATION
Excel Semiconductor inc.
In-System Protection / Unprotection Method
START
START
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
COUNT = 1
RESET# = V
COUNT = 1
RESET# = V
ID
ID
Wait 1us
Wait 1us
No
No
Temporary Sector
Unprotect Mode
First Write
First Write
Temporary Sector
Unprotect Mode
Cycle = 60h?
Cycle = 60h?
Yes
Yes
Set up sector
address
No
All sectors
protected ?
Sector Protect:
Write 60h to sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
Yes
Set up first sector
address
Sector Unpro-
tect:
Write 60h to sec-
tor address with
A6 = 1, A1 = 1,
Wait 150us
Verify Sector
Protect:
Write 40h to sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
Wait 15ms
Increment
COUNT
Reset
COUNT = 1
Verify Sector
Unprotect:
Write 40h to sec-
tor address with
A6 = 1, A1 = 1,
A0 = 0
Set up next
sector address
Read from sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
Increment
COUNT
No
Read from sec-
tor address with
A6 = 1, A1 = 1,
A0 = 0
No
COUNT=25?
Data = 01h?
Yes
No
Yes
No
Yes
COUNT
=1000?
Data = 00h?
Yes
Protectanother
sector?
Device failed
Yes
No
No
Remove V
from RESET#
ID
Last sector
verified?
Device failed
Yes
Write reset
command
Remove V from
ID
RESET#
Sector Protect
complete
Write reset
command
Sector Unprotect
complete
Figure 4. In-System Sector
Unprotect Algorithm
Figure 3. In-System Sector
Protect Algorithm
17
Rev. 0E May 25, 2006
ES29DL320
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
