P R E L I M I N A R Y
The device enters the CMOS standby mode when the
CE# pin is held at V
CC
±
0.5 V. (Note that this is a more
restricted voltage range than V
IH
.) The device enters
the TTL standby mode when CE# is held at V
IH
. The
device requires the standard access time (t
CE
) before it
is ready to read data.
If the device is deselected during erasure or program-
ming, the device draws active current until the
operation is completed.
I
CC3
in the DC Characteristics tables represents the
standby current specification.
Output Disable Mode
When the OE# input is at V
IH
, output from the device is
disabled. The output pins are placed in the high imped-
ance state.
Table 2.
Sector
SA0
SA1
SA2
SA3
SA4
SA5
SA6
SA7
A18
0
0
0
0
1
1
1
1
Sector Addresses Table
A16
0
1
0
1
0
1
0
1
Address Range
00000h–0FFFFh
10000h–1FFFFh
20000h–2FFFFh
30000h–3FFFFh
40000h–4FFFFh
50000h–5FFFFh
60000h–6FFFFh
70000h–7FFFFh
A17
0
0
1
1
0
0
1
1
Note:
All sectors are 64 Kbytes in size.
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 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 V
ID
(11.5 V to 12.5 V) on address pin
A9. Address pins A6, A1, and A0 must be as shown in
Autoselect Codes (High Voltage Method) table. In addi-
tion, when verifying sector protection, the sector ad-
dress must appear on the appropriate highest order
address bits. Refer to the corresponding Sector Ad-
dress Tables. The Command Definitions table 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 the Command Defini-
tions table. This method does not require V
ID
. See
“Command Definitions” for details on using the autose-
lect mode.
Am29F040B
7
AMD [ ADVANCED MICRO DEVICES ]
