AM29LV800BT-70EI AMD (ADVANCED MICRO DEVICES), AM29LV800BT-70EI Datasheet - Page 16

• Manufacturer Part Number: AM29LV800BT-70EI
• Description: IC 8M FLSH (512KX16) TOP SECTO
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Autoselect Mode
The autoselect mode provides manufacturer and
device identification, and sector protection verifica-
tion, through identifier codes output on DQ7–DQ0.
This mode is primarily intended for programming
equipment to automatically match a device to be pro-
grammed with its corresponding programming algo-
rithm. However, the autoselect codes can also be
accessed in-system through the command register.
When using programming equipment, the autoselect
mode requires V
A9. Address pins A6, A1, and A0 must be as shown in
L = Logic Low = V
Address, X = Don’t care.
Sector Protection/Unprotection
The hardware sector protection feature disables both
program and erase operations in any sector. The
hardware sector unprotection feature re-enables both
program and erase operations in previously protected
sectors.
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 pro-
tected or unprotected. See “Autoselect Mode” for
details.
Sector Protection/unprotection can be implemented
via two methods.
The primary method requires V
only, and can be implemented either in-system or via
programming equipment. Figure 2 shows the algo-
rithms and Figure 23 shows the timing diagram. This
method uses standard microprocessor bus cycle
14
Manufacturer ID: AMD
Device ID:
Am29LV800B
(Top Boot Block)
Device ID:
Am29LV800B
(Bottom Boot
Block)
Sector Protection
Verification
Description
IL
ID
, H = Logic High = V
(11.5 V to 12.5 V) on address pin
Table 4. Am29LV800B Autoselect Codes (High Voltage Method)
Mode
Word
Word
Byte
Byte
CE#
L
L
L
L
L
L
ID
OE#
on the RESET# pin
L
L
L
L
L
L
IH
, SA = Sector
WE#
H
H
H
H
H
H
A18
A12
SA
to
X
X
X
Am29LV800B
A11
A10
to
X
X
X
X
V
V
V
V
A9
Table 4. In addition, 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 programming 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 1. This method
does not require V
details on using the autoselect mode.
timing. For sector unprotect, all unprotected sectors
must first be protected prior to the first sector unpro-
tect write cycle.
The alternate method intended only for programming
equipment requires V
This method is compatible with programmer routines
written for earlier 3.0 volt-only AMD flash devices.
Publication number 20536 contains further details;
contact an AMD representative to request a copy.
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
tected sectors can be programmed or erased by
selecting the sector addresses. Once V
from the RESET# pin, all the previously protected
sectors are protected again. Figure 1 shows the algo-
rithm, and Figure 22 shows the timing diagrams, for
this feature.
ID
ID
ID
ID
A8
A7
to
X
X
X
X
A6
L
L
L
L
A5
A2
to
ID
X
X
X
X
ID
. During this mode, formerly pro-
. See “Command Definitions” for
ID
A1
H
L
L
L
on address pin A9 and OE#.
A0
H
H
L
L
DQ15
DQ8
22h
22h
to
X
X
X
X
X
ID
(unprotected
(protected)
is removed
DQ7
DQ0
DAh
DAh
5Bh
5Bh
01h
01h
00h
to
)