AM29LV200 AMD [Advanced Micro Devices], AM29LV200 Datasheet - Page 10

• Manufacturer Part Number: AM29LV200
• Description: 2 Megabit (256 K x 8-Bit/128 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

L = Logic Low = V
Sector Protection/Unprotection
The hardware sector protection feature disables both
program and erase operations in any sector. The hard-
ware sector unprotection feature re-enables both pro-
gram and erase operations in previously protected
sectors.
Sector protection/unprotection must be implemented
using programming equipment.The procedure requires
a high voltage (V
tails on this method are provided in a supplement, pub-
lication number 21226. Contact an AMD representative
to request a copy.
The device is shipped with all sectors unprotected.
AMD offers the option of programming and protecting
sectors at its factory prior to shipping the device
through AMD’s ExpressFlash™ Service. Contact an
AMD representative for details.
It is possible to determine whether a sector is protected
or unprotected. See “Autoselect Mode” for details.
Temporary Sector Unprotect
This feature allows temporary unprotection of previ-
ously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the RE-
SET# pin to V
sectors can be programmed or erased by selecting the
sector addresses. Once V
SET# pin, all the previously protected sectors are
protected again. Figure 1 shows the algorithm, and
Figure 21 shows the timing diagrams, for this feature.
Manufacturer ID: AMD
Device ID:
Am29LV200
(Top Boot Block)
Device ID:
Am29LV200
(Bottom Boot
Block)
Sector Protection Verification
Description
ID
. During this mode, formerly protected
IL
ID
, H = Logic High = V
) on address pin A9 and OE#. De-
Mode
Word
Word
Byte
Byte
Table 4. Am29LV200 Autoselect Codes (High Voltage Method)
ID
CE#
is removed from the RE-
L
L
L
L
L
L
OE#
IH
L
L
L
L
L
L
, SA = Sector Address, X = Don’t care.
WE#
H
H
H
H
H
H
P R E L I M I N A R Y
A16
A12
SA
to
X
X
X
Am29LV200
A11
A10
to
X
X
X
X
V
V
V
V
A9
Notes:
1. All protected sectors unprotected.
2. All previously protected sectors are protected once
Figure 1. Temporary Sector Unprotect Operation
ID
ID
ID
ID
again.
A8
A7
to
X
X
X
X
A6
L
L
L
L
A5
A2
to
X
X
X
X
Unprotect Completed
Program Operations
Temporary Sector
Perform Erase or
A1
H
L
L
L
RESET# = V
RESET# = V
(Note 1)
(Note 2)
START
A0
H
H
L
L
DQ15
DQ8
22h
22h
ID
IH
to
X
X
X
X
X
(unprotected)
(protected)
DQ7
DQ0
BFh
BFh
01h
3Bh
3Bh
01h
00h
20513D-5
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