P r e l i m i n a r y
Sector protect/Sector Unprotect requires VID on the RESET# pin only, and can be
implemented either in-system or via programming equipment. Figure 2 shows
the algorithms and Figure 26 shows the timing diagram. For sector unprotect, all
unprotected sectors must first be protected prior to the first sector unprotect
write cycle. Note that the sector unprotect algorithm unprotects all sectors in par-
allel. All previously protected sectors must be individually re-protected. To
change data in protected sectors efficiently, the temporary sector unprotect func-
tion is available. See “Temporary Sector Unprotect” .
The device is shipped with all sectors unprotected. Optional Spansion program-
ming service enable programming and protecting sectors at the factory prior to
shipping the device. Contact your local sales office for details.
It is possible to determine whether a sector is protected or unprotected. See the
Autoselect Mode section for details.
Write Protect (WP#)
The Write Protect function provides a hardware method of protecting without
using VID. This function is one of two provided by the WP#/ACC pin.
If the system asserts VIL on the WP#/ACC pin, the device disables program and
erase functions in sectors 0, 1, 140, and 141, independently of whether those
sectors were protected or unprotected using the method described in “Sector/
Sector Block Protection and Unprotection”.
If the system asserts VIH on the WP#/ACC pin, the device reverts to whether sec-
tors 0, 1, 140, and 141 were last set to be protected or unprotected. That is,
sector protection or unprotection for these sectors depends on whether they were
last protected or unprotected using the method described in “Sector/Sector Block
Protection and Unprotection”.
Note that the WP#/ACC pin must not be left floating or unconnected; inconsistent
behavior of the device may result.
Table 7. WP#/ACC Modes
Device
WP# Input Voltage
Mode
VIL
Disables programming and erasing in SA0, SA1, SA140, and SA141
Enables programming and erasing in SA0, SA1, SA140, and SA141, dependent on
whether they were last protected or unprotected.
VIH
Enables accelerated progamming (ACC). See “Accelerated Program Operation” on
page 12..
VHH
Temporary Sector Unprotect
(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 Table 6).
This feature allows temporary unprotection of previously protected sectors to
change data in-system. The Temporary Sector Unprotect mode is activated 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.
shows the algorithm, and 25 shows the timing diagrams, for this feature. If the
WP#/ACC pin is at VIL, sectors 0, 1, 140, and 141 will remain protected during
the Temporary sector Unprotect mode.
March 26, 2004 S29JL064HA1
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SPANSION [ SPANSION ]
