sequence is illustrated in Table 5 (see Autoselect Com-
mand Sequence).
Autoselect
The autoselect mode allows the reading of a binary
code from the device and will identify its manufacturer
and type. This mode is intended for use by program-
ming equipment for the purpose of automatically
matching the device to be programmed with its corre-
sponding programming algorithm. This mode is func-
tional over the entire temperature range of the device.
Byte 0 (A0 = VIL) represents the manufacturer’s code
(AMD = 01H) and byte 1 (A0 = VIH) the device identifier
code for Am29F016 = ADH. These two bytes are given
in the table below. All identifiers for manufacturer and
device will exhibit odd parity with DQ7 defined as the
parity bit. In order to read the proper device codes
when executing the Autoselect, A1 must be VIL (see
Table 2).
To activate this mode, the programming equipment
must force VID (11.5 V to 12.5 V) on address pin A9.
Two identifier bytes may then be sequenced from the
device outputs by toggling address A0 from VIL to VIH.
All addresses are don’t cares except A0, A1, and A6
(seeTable 2).
The autoselect mode also facilitates the determination
of sector group protection in the system. By performing
a read operation at the address location XX02H with
the higher order address bits A18, A19, and A20 set to
the desired sector group address, the device will return
01H for a protected sector group and 00H for a
non-protected sector group.
The manufacturer and device codes may also be read
via the command register, for instances when the
Am29F016 is erased or programmed in a system with-
out access to high voltage on the A9 pin. The command
Table 2. Am29F016 Sector Protection Verify Autoselect Codes
Code
(HEX)
Type
A18 to A20
A6
A1
A0
DQ7 DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0
Manufacturer Code–AMD
X
X
X
X
VIL
VIL
VIL
VIL
01H
0
1
0
0
0
1
0
0
0
1
0
1
0
0
1
1
Am29F016 Device
X
X
VIL VIH
ADH
Sector Group
Address
Sector Group Protection
VIL VIH VIL
01H*
0
0
0
0
0
0
0
1
* Outputs 01H at protected sector addresses
Am29F016
9
AMD [ AMD ]
