S29AL004D SPANSION, S29AL004D Datasheet - Page 17

• Manufacturer Part Number: S29AL004D
• Description: 4 Megabit (512 Kx 8-Bit/256 K x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory
• Manufacturer: SPANSION

L = Logic Low = V
February 18, 2005 S29AL004D_00_A1
Manufacturer ID:
Spansion
Device ID:
S29AL004D
(Top Boot Block)
Device ID:
S29AL004D
(Bottom Boot
Block)
Sector Protection
Verification
Description
Sector Protection/Unprotection
Temporary Sector Unprotect
Mode
Word
Word
To access the autoselect codes in-system, the host system can issue the autose-
lect command via the command register, as shown in
method does not require V
on using the autoselect mode.
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
Sector Protection/unprotection can be implemented via two methods.
The primary method requires V
mented either in-system or via programming equipment.
shows the algorithms and
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
address pin A9 and OE#. This method is compatible with programmer routines
written for earlier 3.0 volt-only Spansion flash devices.
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
grammed or erased by selecting the sector addresses. Once V
the RESET# pin, all the previously protected sectors are protected again.
Byte
Byte
Autoselect Mode‚ on page 14
IL
, H = Logic High = V
CE#
Table 4. S29AL004D Autoselect Codes (High Voltage Method)
L
L
L
L
L
L
A d v a n c e
OE#
L
L
L
L
L
L
ID
WE#
. During this mode, formerly protected sectors can be pro-
H
H
H
H
H
H
IH
, SA = Sector Address, X = Don’t care.
A17
A12
SA
to
Figure 23, on page 46
X
X
X
ID
I n f o r m a t i o n
. See
for details.
A11
A10
to
X
X
X
X
ID
S29AL004D
on the RESET# pin only, and can be imple-
Command Definitions‚ on page 18
V
V
V
V
A9
ID
ID
ID
ID
A8
A7
to
X
X
X
X
A6
L
L
L
L
shows the timing diagram. This
A4
A5
to
X
X
X
X
Table on page
Figure 2, on page 17
A3
A2
to
L
L
L
L
ID
is removed from
A1
H
L
L
L
for details
A0
H
H
L
L
24. This
ID
DQ15
DQ8
22h
22h
to
on
X
X
X
X
X
(unprotected)
(protected)
DQ7
DQ0
01h
B9h
B9h
BAh
BAh
01h
00h
to
15