ES29LV800D Datasheet, PDF (13/50 Pages) Excel Semiconductor Inc. – 8Mbit(1M x 8/512K x 16) CMOS 3.0 Volt-only, Boot Sector Flash Memory

EE SS II
Excel Semiconductor inc.
In-System Protection / Unprotection Method
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
Increment
COUNT
Verify Sector
Protect:
Write 40h to sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
No
COUNT=25?
Read from sec-
tor address with
A6 = 0, A1 = 1,
A0 = 0
No
Data = 01h?
Yes
Device failed
Yes
Protect another ^Yes
sector?
No
Remove V_ID
from RESET#
Write reset
command
Sector Protect
complete
Reset
COUNT = 1
Figure 2. In-System Sector
Protect Algorithm
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
Increment
COUNT
No
COUNT
=1000?
Yes
Device failed
START
COUNT = 1
RESET# = V_ID
Wait 1us
First Write
No
Cycle = 60h?
Yes
No
All sectors
protected ?
Yes
Set up first sector
address
Temporary Sector
Unprotect Mode
Sector Unpro-
tect:
Write 60h to sec-
tor address with
A6 = 1, A1 = 1,
Wait 15ms
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 = 1, A1 = 1,
A0 = 0
No
Data = 00h?
Yes
Last sector ^No
verified?
Yes
Remove V_ID from
RESET#
Write reset
command
Sector Unprotect
complete
Figure 3. In-System Sector
Unprotect Algorithm
ES29LV800D
13
Rev. 1D January 5, 2006