16 Am29DL320G
Autoselect Mode
The autoselect mode provides manufacturer and de-
vice identification, and sector protection verification,
through identifier codes output on DQ7–DQ0. This
mode is primar ily intended for programming equip-
ment to automatically match a device to be pro-
grammed with its corresponding programming
algorithm. H owever, the autoselect codes can also be
accessed in-system through the command register.
When using programming equipment, the autoselect
mode requires V
ID
(8.5 V to 12.5 V) on address pin A9.
Address pins A6, A1, and A0 must be as shown in
Table 6. In addition, when verifying secto r protection,
the sector address must appear on the appropriate
highest order address bits (see Table 2). Ta ble 6
shows the remaining address bits that are don’t care.
When all necessar y bits have been set as required,
the programming equipment may then read the corre-
sponding 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 13. This method
does not require V
ID
. Refer to the Autoselect Com-
mand Sequence section for more information.
Table 6. Autoselect Codes, (High Voltage Method)
Legend: T = Top Boot Block, B = Bottom Boot Block, L = Logic Low = V
IL
, H = Logic High = V
IH
, BA = Bank Address, SA = Sector Address , X =
Don’t care.
Notes:
1. The bank address bits are A20–A18.
2. The device ID must be read across three cycles.
Description CE# OE# WE#
A20
to
A12
A11
to
A10 A9
A8
to
A7 A6
A5
to
A4
A3 A2
A1 A0
DQ15 to DQ8
DQ7
to
DQ0
BYTE#
= V
IH
BYTE#
= V
IL
Manufacturer ID:
AMD
LLHBAX
V
ID
X L X X X L L X X 01h
Device ID
Read Cycle 1 L L H BA X
V
ID
XLXLLLH22h X 7Eh
Read Cycle 2 L L H BA X
V
ID
X L XHHHL 22h X 0Ah
Read Cycle 3 L L H BA X
V
ID
X L X H H H H 22h X 01h (T), 00h (B)
Sector Protection
Verification
LLHSAX
V
ID
XLXXXHL X X
01h (protected),
00h (unprotected)
SecSi™ Indicator
Bit (DQ7)
LLHBAX
V
ID
XLXXXHH X X
82h (factory locked),
02h (not factory
locked)