A400CB10RC AMD [Advanced Micro Devices], A400CB10RC Datasheet - Page 14

• Manufacturer Part Number: A400CB10RC
• Description: 4 Megabit (512 K x 8-Bit/256 K x 16-Bit) CMOS 1.8 Volt-only Super Low Voltage Flash Memory
• Manufacturer: AMD [Advanced Micro Devices]

L = Logic Low = V
Sector Protection/Unprotection
The hardware sector protection feature disables both pro-
gram and erase operations in any sector. The hardware sec-
tor unprotection feature re-enables both program and erase
operations in previously protected sectors. Sector protec-
tion/unprotection can be implemented via two methods.
Sector protection/unprotection requires V
pin only, and can be implemented either in-system or via
programming equipment.
gorithms and
gram. This method uses standard microprocessor bus cycle
timing. For sector unprotect, all unprotected sectors must
first be protected prior to the first sector unprotect write cy-
cle.
The device is shipped with all sectors unprotected. AMD of-
fers the option of programming and protecting sectors at its
12
Manufacturer ID: AMD
Device ID:
Am29SL400C
(Top Boot Block)
Device ID:
Am29SL400C
(Bottom Boot Block)
Sector Protection Verification
Description
Figure 24‚ on page 37
IL
, H = Logic High = V
Mode
Word
Word
Byte
Byte
Table 4. Am29SL400C Autoselect Codes (High Voltage Method)
Figure 2‚ on page 14
CE#
L
L
L
L
L
L
IH
, SA = Sector Address, X = Don’t care.
shows the timing dia-
OE#
L
L
L
L
L
L
ID
on the RESET#
WE#
shows the al-
H
H
H
H
H
H
D A T A
A17t
A12
SA
X
X
X
o
Am29SL400C
A11
A10
to
X
X
X
X
S H E E T
V
V
V
V
factory prior to shipping the device through AMD’s Express-
Flash™ Service. Contact an AMD representative for details.
It is possible to determine whether a sector is protected or
unprotected. See
Temporary Sector Unprotect
This feature allows temporary unprotection of previously pro-
tected sectors to change data in-system. The Sector Unpro-
tect mode is activated by setting the RESET# pin to V
During this mode, formerly protected sectors can be pro-
grammed or erased by selecting the sector addresses. Once
V
tected sectors are protected again.
shows the algorithm, and Figure 22 shows the timing dia-
grams, for this feature.
A9
ID
ID
ID
ID
ID
is removed from the RESET# pin, all the previously pro-
A8
A7
to
X
X
X
X
A6
L
L
L
L
Autoselect Mode‚ on page 11
A5
A2
to
X
X
X
X
A1
H
L
L
L
Am29SL400C_00_A6 January 23, 2007
A0
H
H
L
L
DQ15
Figure 3‚ on page 16
DQ8
22h
22h
to
X
X
X
X
X
01h (protected)
(unprotected)
for details.
DQ7
DQ0
F1h
F1h
01h
70h
70h
00h
to
ID
.