AM29F004B AMD [Advanced Micro Devices], AM29F004B Datasheet - Page 13

• Manufacturer Part Number: AM29F004B
• Description: 4 Megabit (512 K x 8-Bit) CMOS 5.0 Volt-only Boot Sector Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

8/5/05
Device failed
Sector Protect
Increment
PLSCNT
PLSCNT
Algorithm
= 25?
No
Yes
No
with command 24h
Write 60h to sector
Protect: Write 40h
Wait 150 ± 15 μs
Relock sequence.
to sector address
Unlock sequence
Set OE# = V ID .
Set OE# = V ID .
Write 60h to any
A6 = 0, A5 = 1,
Set OE# = V IH .
A6 = 0, A5 = 1,
Set OE# = V IH
Sector Protect:
A1 = 1, A0 = 0
A1 = 1, A0 = 0
Set OE# = V IL
A1 = 1, A0 = 0
Protect another
A1 = 1, A0 = 0
sector address
(requires 1 μs
Sector Protect
Verify Sector
Set up sector
with A6 = 0,
with A6 = 0,
Write Sector
Write Sector
address with
address with
access time)
Data = 01h?
PLSCNT = 1
Read from
Wait 1 ms
complete
address
sector?
Figure 1. In-System Sector Protect/Sector Unprotect Algorithms
START
Yes
No
A D V A N C E
Yes
PLSCNT = 1
Reset
Am29F004B
I N F O R M A T I O N
The indicated portion
unprotected sectors
of the sector protect
prior to issuing the
Protect all sectors:
unprotect address
algorithm must be
performed for all
first sector
Sector Unprotect
Device failed
Increment
Algorithm
= 1000?
PLSCNT
PLSCNT
Yes
No
No
No
with command 24h
Write 60h to sector
Set up first sector
Sector Unprotect:
Unlock sequence
Wait 15 ± 1.5 ms
Unprotect: Write
Relock sequence.
Sector Unprotect
Set OE# = V ID .
any address with
A6 = 1, A1 = 1,
A6 = 1, A5 = 1,
Set OE# = V ID .
A6 = 1, A5 = 1,
Set OE# = V IH
A1 = 1, A0 = 0
A1 = 1, A0 = 0
Set OE# = V IH .
A1 = 1, A0 = 0
Set OE# = V IL
sector address
40h to sector
(requires 1 μs
Verify Sector
Write Sector
address with
with A6 = 1,
address with
access time)
Write Sector
Write 60h to
Data = 00h?
PLSCNT = 1
Read from
Last sector
Wait 1 ms
protected?
All sectors
complete
verified?
address
A0 = 0
START
Yes
Yes
Yes
No
next sector
address
Set up
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