s29as008j Meet Spansion Inc., s29as008j Datasheet - Page 19

• Manufacturer Part Number: s29as008j
• Description: 8 Megabit 1 M X 8-bit/512 K X 16-bit Cmos 1.8 Volt-only Boot Sector Flash Memory
• Manufacturer: Meet Spansion Inc.

7.11
June 6, 2008 S29AS008J_00_03
Sector Protection/Unprotection
(Note: For the following discussion, the term “sector” applies to both sectors and sector blocks. A sector block
consists of two or more adjacent sectors that are protected or unprotected at the same time (see
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. Spansion offers the option of programming and protecting
sectors at its factory prior to shipping the device through Spansion’s ExpressFlash™ Service. Contact a
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
RESET# pin only, and can be implemented either in-system or via programming equipment.
on page 20
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
is compatible with programmer routines written for earlier 3.0 volt-only Spansion flash devices. Contact a
Spansion representative for more information.
D a t a
Autoselect Mode on page 16
Sector / Sector Block
SA12–SA13
SA8–SA11
SA0–SA3
SA4–SA7
shows the algorithms and
SA14
SA15
SA16
SA17
SA18
SA19
SA20
SA21
SA22
S h e e t
Table 7.5 Sector Block Addresses for Protection/Unprotection
Top Boot
( A d v a n c e
Sector / Sector Block Size
256 (4 x 64) Kbytes
256 (4 x 64) Kbytes
256 (4 x 64) Kbytes
128 (2 x 64) Kbytes
for details.
64 Kbytes
Figure 18.11 on page 49
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
S29AS008J
I n f o r m a t i o n )
Sector / Sector Block
shows the timing diagram. This method uses
SA11–SA14
SA15–SA18
SA19–SA22
SA9–SA10
SA0
SA1
SA2
SA3
SA4
SA5
SA6
SA7
SA8
ID
Bottom Boot
on address pin A9. This method
Sector / Sector Block Size
128 (2 x 64) Kbytes
256 (4 x 64) Kbytes
256 (4 x 64) Kbytes
256 (4 x 64) Kbytes
64 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
8 Kbytes
Figure 7.1
Table
ID
on the
7.5).
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