AM29SL400DB90 SPANSION [SPANSION], AM29SL400DB90 Datasheet - Page 13

• Manufacturer Part Number: AM29SL400DB90
• Description: 4 Megabit (512 K x 8-Bit/256 K x 16-Bit) CMOS 1.8 Volt-only Super Low Voltage Flash Memory
• Manufacturer: SPANSION [SPANSION]

Autoselect Mode
The autoselect mode provides manufacturer and
device identification, and sector protection verification,
through identifier codes output on DQ7–DQ0. This
mode is primarily intended for programming equipment
to automatically match a device to be programmed with
its corresponding programming algorithm. However,
the autoselect codes can also be accessed in-system
through the command register.
When using programming equipment, the autoselect
mode requires VID on address pin A9. Address pins
A6, A1, and A0 must be as shown in
tion, when verifying sector protection, the sector
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
program and erase operations in previously protected
sectors. Sector protection/unprotection can be imple-
mented via two methods.
Sector protection/unprotection requires V
RESET# pin only, and can be implemented either
in-system or via programming equipment.
page 12
page 34
standard microprocessor bus cycle timing. For sector
unprotect, all unprotected sectors must first be pro-
tected prior to the first sector unprotect write cycle.
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
April 13, 2005 Rev. A Amend. +1
Manufacturer ID: AMD
Device ID:
Am29SL400D
(Top Boot Block)
Device ID:
Am29SL400D
(Bottom Boot Block)
Sector Protection Verification
Description
shows the timing diagram. This method uses
shows the algorithms and
IL
, H = Logic High = V
Mode
Word
Word
Byte
Byte
Table 4. Am29SL400D Autoselect Codes (High Voltage Method)
CE#
L
L
L
L
L
L
A D V A N C E
OE#
IH
L
L
L
L
L
L
, SA = Sector Address, X = Don’t care.
Table
Figure 23, on
WE#
Figure 1, on
H
H
H
H
H
H
4. In addi-
ID
on the
A17
A12
SA
to
X
X
X
Am29SL400D
I N F O R M A T I O N
A11
A10
to
X
X
X
X
V
V
V
V
address must appear on the appropriate highest order
address bits (see Tables 2 and 3).
remaining address bits that are don’t care. When all
necessary bits have been set as required, the program-
ming equipment may then read the corresponding
identifier code on DQ7–DQ0.
To access the autoselect codes in-system, the host
system can issue the autoselect command via the
command register, as shown in
This method does not require VID. See “ Command
Definitions, on page 13 for details on using the autose-
lect mode.
A9
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, on page 11 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
RESET# pin to V
tected sectors can be programmed or erased by
selecting the sector addresses. Once V
from the RESET# pin, all the previously protected
sectors are protected again.
shows the algorithm, and
the timing diagrams, for this feature.
ID
ID
ID
ID
A8
A7
to
X
X
X
X
A6
L
L
L
L
A5
A2
to
X
X
X
X
ID
. During this mode, formerly pro-
A1
H
L
L
L
Figure 22, on page 33
A0
H
H
L
L
Figure 2, on page 13
Table 5 on page
DQ15
DQ8
22h
22h
Table 4
to
X
X
X
X
X
ID
(unprotected)
(protected)
is removed
shows the
DQ7
DQ0
F1h
F1h
01h
70h
70h
01h
00h
to
shows
17.
11