AM29LV800T Datasheet, PDF (11/48 Pages) Advanced Micro Devices – 8 Megabit (1,048,576 x 8-Bit/524,288 x 16-Bit) CMOS 3.0 Volt-only, Sectored Flash Memory

PRELIMINARY
Autoselect
The Autoselect mode allows the reading out of a binary
code from the device and will identify its manufacturer
and type. The intent is to allow programming equipment
to automatically match the device to be programmed
with its corresponding programming algorithm. The
Autoselect command may also be used to check the
status of write-protected sectors (see Table 3). This
mode is functional over the entire temperature range of
the device.
To activate this mode, the programming equipment
must force V_ID (11.5–12.5 volts) on address pin A9.
Two identifier bytes may then be sequenced from the
device outputs by toggling address A0 from V_IL to V_IH.
All addresses are don’t cares except A0, A1, and A6
(see Table 3).
The manufacturer and device codes may also be read
via the command register, for instances when the
Am29LV800 is erased or programmed in a system
without access to high voltage on the A9 pin. The
command sequence is illustrated in Table 6.
Byte 0 (A0 = V_IL) represents the manufacturer’s code
and byte 1 (A0 = V_IH) the device identifier code. These
two bytes are given for the Am29LV800 in Table 3. All
identifiers for manufacturer and device exhibit odd
parity with DQ7 defined as the parity bit. In order to
read the proper device codes when executing Autose-
lect, A1 must be V_IL (see Table 3). For device identifica-
tion in word mode (BYTE = V_IH), DQ9 and DQ13 are
equal to ‘1’ and DQ8, DQ10–12, DQ14, and DQ15 are
equal to ‘0’.
If BYTE = V_IH (for word mode), the device code is 22DAh
(for top boot block) or 225Bh (for bottom boot block). If
BYTE = V_IL (for byte mode), the device code is DAh (for
top boot block) or 5Bh (for bottom boot block).
In order to determine which sectors are write protected,
A1 must be at V_IH while running through the sector
addresses. If the selected sector is protected, the
device outputs a ‘1’ on DQ0.
Table 3. Autoselect/Sector Protection Codes
Type
Code
DQ DQ DQ DQ DQ DQ DQ DQ
Mode A12–A18 A6 A1 A0 (HEX) DQ8–DQ15 7 6 5 4 3 2 1 0
Manufacturer Code:
AMD
X
L L L 01h
High-Z
00000001
DQ9 = 1,
29LV800 Device
(Top Boot Block)
Word
X
22DAh DQ13 = 1,
L LH
Others = 0 ^{1 1 0 1 1 0 1 0}
Byte
X
DAh
High-Z
DQ9 = 1,
29LV800 Device
Word
(Bottom Boot Block)
X
225Bh DQ13 = 1,
L LH
Others = 0 ^{0 1 0 1 1 0 1 1}
Byte
X
5Bh
High-Z
Sector Protection
Set Sector
Addresses
L
H
L
01h*
X
00000001
X = Don’t care.
* Outputs 01h at protected sector addresses.
Am29LV800T/Am29LV800B
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