AM29SL800D Datasheet, PDF (14/46 Pages) Advanced Micro Devices – 8 Megabit (1 M x 8-Bit/512 K x 16-Bit) CMOS 1.8 Volt-only Super Low Voltage Flash Memory

ADVANCE INFORMATION
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 Table 4. In addi-
tion, when verifying sector protection, the sector
address must appear on the appropriate highest order
address bits (see Tables 2 and 3). Table 4 shows the
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 Table 5. This method
does not require VID. See “Command Definitions” for
details on using the autoselect mode.
Table 4. Am29SL800D Autoselect Codes (High Voltage Method)
Description
A18 A11
A8
A5
DQ8
to to
to
to
to
Mode CE# OE# WE# A12 A10 A9 A7 A6 A2 A1 A0 DQ15
DQ7
to
DQ0
Manufacturer ID: AMD
L
L
H X X V_ID X L X L L
X
01h
Device ID:
Word L
L
H
22h
EAh
Am29SL800D
X X V_ID X L X L H
(Top Boot Block)
Byte L
LH
X
EAh
Device ID:
Word L
L
H
22h
6Bh
Am29SL800D
X X V_ID X L X L H
(Bottom Boot Block) ^{Byte L}
L
H
X
6Bh
Sector Protection Verification L
L
H SA X V_ID X L X H L
X
01h
(protected)
X
00h
(unprotected)
L = Logic Low = V_IL, H = Logic High = V_IH, SA = Sector Address, X = Don’t care.
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_ID on the
RESET# pin only, and can be implemented either in-
system or via programming equipment. Figure 1 shows
the algorithms and Figure 23 shows the timing dia-
gram. For sector unprotect, all unprotected sectors
must first be protected 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
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
RESET# pin to V_ID. During this mode, formerly pro-
tected sectors can be programmed or erased by
selecting the sector addresses. Once V_ID is removed
from the RESET# pin, all the previously protected
sectors are protected again. Figure 2 shows the algo-
rithm, and Figure 22 shows the timing diagrams, for
this feature.
March 17, 2003
Am29SL800D
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