am49pdl129bh85it Meet Spansion Inc., am49pdl129bh85it Datasheet - Page 43

• Manufacturer Part Number: am49pdl129bh85it
• Description: Stacked Multi-chip Package Mcp Flash Memory And Psram, 128 Megabit 8m ? 16-bit Cmos 3.0 Volt-only, Simultaneous Operation Flash Memory And 32 Mbit 2m ? 16-bit Cmos Pseudo Static Ram With Page Mode
• Manufacturer: Meet Spansion Inc.

Once the SecSi Sector is locked and verified, the sys-
tem must write the Exit SecSi Sector Region com-
mand sequence to return to reading and writing the
remainder of the array.
The SecSi Sector lock must be used with caution
since, once locked, there is no procedure available for
December 16, 2003
To verify the protect/unprotect status of the SecSi
Sector, follow the algorithm shown in Figure 4.
Increment PLSCNT
PLSCNT = 25?
Device Failed
No
Yes
Figure 3. PDL127H/129H SecSi Sector Protection Algorithm
A D V A N C E
Am49PDL127BH/Am49PDL129BH
write 48h to sector address
write 68h to sector address
Write AAh to address 555h
Write 55h to address 2AAh
Write AAh to address 555h
Write 55h to address 2AAh
Write 60h to address 555h
Write 88h to address 555h
No
Read from sector address
with A7–A0 = 00011010
with A7–A0 = 00011010
with A7–A0 = 00011010
Protect SecSi Sector:
Protection Completed
SecSi
Verify SecSi Sector:
Write SA0+555h/90h
SecSi Sector Exit
Protection Entry
Time out 256 µs
Write 555h/AAh
Write 2AAh/55h
Write XXXh/00h
SecSi Sector
SecSi Sector
PLSCNT = 1
Data = 01h?
TM
START
I N F O R M A T I O N
Sector Entry
Yes
unlocking the SecSi Sector area and none of the bits
in the SecSi Sector memory space can be modified in
any way.
SecSi Sector Protection Bits
The SecSi Sector Protection Bits prevent program-
ming of the SecSi Sector memory area. Once set, the
SecSi Sector Entry
SecSi Sector Protection
SecSi Sector Exit
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