P R E L I M I N A R Y
Table 4. Am29LV800D Autoselect Codes (High Voltage Method)
A1 A1
8
1
to
to
A8
to
A5
to
DQ8
to
DQ7
to
WE A1 A1
Description
Mode CE# OE#
#
H
H
2
0
A9 A7 A6 A2 A1 A0 DQ15
DQ0
Manufacturer ID: AMD
L
L
L
L
X
X
V
X
L
X
L
L
X
01h
DAh
ID
Device ID:
Word
22h
Am29LV800B
(Top Boot Block)
X
X
X
X
V
X
L
X
L
H
ID
Byte
L
L
L
L
H
H
X
DAh
5Bh
Device ID:
Am29LV800B
(Bottom Boot
Block)
Word
22h
V
V
X
X
L
L
X
X
L
H
L
ID
Byte
L
L
H
X
X
5Bh
01h
(protected)
Sector Protection
Verification
L
L
H
SA
X
H
ID
00h
(unprotecte
d)
X
L = Logic Low = V , H = Logic High = V , SA = Sector Address, X = Don’t care.
IL
IH
standard microprocessor bus cycle timing. For
sector unprotect, all unprotected sectors must
first be protected prior to the first sector unpro-
tect write cycle.
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 alternate method intended only for pro-
gramming equipment requires VID on address
pin A9 and OE#. 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.
The device is shipped with all sectors unpro-
tected. AMD offers the option of programming
and protecting sectors at its factory prior to
shipping the device through AMD’s Express-
Flash™ Service. Contact an AMD representative
for details.
Temporary Sector Unprotect
It is possible to determine whether a sector is
protected or unprotected. See “Autoselect
Mode” for details.
This feature allows temporary unprotection of
previously protected sectors to change data
in-system. The Sector Unprotect mode is acti-
vated by setting the RESET# pin to VID. During
this mode, formerly protected sectors can be
programmed or erased by selecting the sector
addresses. Once VID is removed from the
RESET# pin, all the previously protected sectors
are protected again. Figure 1 shows the algo-
Sector Protection/unprotection can be imple-
mented via two methods.
The primary method requires VID on the
RESET# pin only, and can be implemented
either in-system or via programming equip-
ment. Figure 2 shows the algorithms and Figure
1 shows the timing diagram. This method uses
14
Am29LV800D
Am29LV800D_00_A4_E January 21, 2005
AMD [ AMD ]
