A d v a n c e I n f o r m a t i o n
To access the autoselect codes in-system, the host system can issue the autose-
lect command via the command register, as shown in Table on page 24. This
method does not require V . See Command Definitions‚ on page 18 for details
ID
on using the autoselect mode.
Table 4. S29AL004D Autoselect Codes (High Voltage Method)
A17 A11
to to
A12 A10
A8
to
A4
to
A3
to
DQ8
to
DQ7
to
Description
Mode CE#
OE#
WE#
A9
A6
L
A1
L
A0
L
A7
A5
A2
DQ15
DQ0
Manufacturer ID:
Spansion
L
L
H
X
X
X
X
V
V
X
X
X
X
L
L
X
01h
ID
ID
Device ID:
S29AL004D
(Top Boot Block) Byte
Word
L
L
L
L
L
L
H
H
H
22h
X
B9h
B9h
BAh
L
L
H
Device ID:
S29AL004D
(Bottom Boot
Block)
Word
Byte
22h
X
X
X
V
V
X
X
L
L
X
X
L
L
L
H
L
ID
ID
L
L
H
X
X
X
BAh
01h
(protected)
Sector Protection
Verification
L
L
H
SA
H
00h
(unprotected)
L = Logic Low = VIL, H = Logic High = VIH, SA = Sector Address, X = Don’t care.
Sector Protection/Unprotection
The hardware sector protection feature disables both program and erase opera-
tions 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. Spansion offers the option of
programming and protecting sectors at its factory prior to shipping the device
through Spansion’s ExpressFlash™ Service. Contact an Spansion representative
for details.
It is possible to determine whether a sector is protected or unprotected. See
Autoselect Mode‚ on page 14 for details.
Sector Protection/unprotection can be implemented via two methods.
The primary method requires V on the RESET# pin only, and can be imple-
ID
mented either in-system or via programming equipment. Figure 2, on page 17
shows the algorithms and Figure 23, on page 46 shows the timing diagram. This
method uses standard microprocessor bus cycle timing. For sector unprotect, all
unprotected sectors must first be protected prior to the first sector unprotect
write cycle.
The alternate method intended only for programming equipment requires V on
ID
address pin A9 and OE#. This method is compatible with programmer routines
written for earlier 3.0 volt-only Spansion flash devices.
Temporary Sector Unprotect
This feature allows temporary unprotection of previously protected sectors to
change data in-system. The Sector Unprotect mode is activated by setting the
RESET# pin to V . During this mode, formerly protected sectors can be pro-
ID
grammed or erased by selecting the sector addresses. Once V is removed from
ID
the RESET# pin, all the previously protected sectors are protected again.
February 18, 2005 S29AL004D_00_A1
S29AL004D
15
SPANSION [ SPANSION ]
