EN29LV640 Datasheet, PDF (30/45 Pages) Eon Silicon Solution Inc. – 64 Megabit (4M x 16-bit ) CMOS 3.0 Volt-only, Uniform Sector Flash Memory

Flowchart 6b. In-System Sector Group Unprotect Flowchart
START
EN29LV640
Protect all sector
groups: The
indicated portion of
the sector group
protect algorithm
must be performed
for all unprotected
sectors prior to
issuing the first
sector unprotect
address (see
Diagram 6a.)
PLSCNT = 1
RESET# = VID
Wait 1 μS
No
First Write
Cycle = 60h?
Temporary Sector
Group Unprotect Mode
Yes
No
All sectors
protected?
Yes
Set up first sector
group address
Unprotect: Write 60H to sector
address with A6 = 1,
A1 = 1, A0 = 0
Increment
PLSCNT
Wait 15 ms
Verify Unprotect: Write 40h
to sector address with A6 =
1, A1 = 1, A0 =0
Wait 0.4 μS
Read from sector group address
with A6 = 1, A1 = 1, A0 = 0
No
PLSCCNT =
1000?
Yes
Device failed
No
Data = 00h?
Yes
Set up next sector
group address
Last sector
No
group
verified?
Yes
Remove V_ID from
RESET#
Write reset
command
Sector Group
Unprotect complete
Sector Group Unprotect Algorithm
This Data Sheet may be revised by subsequent versions ₃₀ ©2005 Eon Silicon Solution, Inc., www.essi.com.tw
or modifications due to changes in technical specifications.
Rev. C, Issue Date: 2007/01/23