EN29LV320A
Flowchart 7b. In-System Chip Unprotect Flowchart
START
PLSCNT = 1
Protect all sectors
(groups): The
indicated portion of
RESET# = VID
the sector protect
algorithm must be
Wait 1 μS
performed for all
unprotected sectors
prior to issuing the
No
first sector unprotect
Temporary Chip
Unprotect Mode
First Write
Cycle = 60h?
address (see
Diagram 7a.)
Yes
No
All sectors
protected?
Yes
Set up first sector
address
Chip Unprotect: Write 60H to sector
address with A6 = 1,
A1 = 1, A0 = 0
Wait 15 ms
Verify Chip Unprotect: Write
40h to sector address with
A6 = 1, A1 = 1, A0 =0
Increment
PLSCNT
Wait 0.4 μS
Read from sector address with
A6 = 1, A1 = 1, A0 = 0
No
No
PLSCCNT =
1000?
Set up next sector
(group) address
Data = 00h?
Yes
Yes
No
Last sector
verified?
Device failed
Yes
Remove VID from
RESET#
Write reset
command
Chip Unprotect
complete
Chip Unprotect Algorithm
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.essi.com.tw
30
Rev. B, Issue Date: 2007/07/17
EON [ EON SILICON SOLUTION INC. ]
