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A29DL322TV-80 Ver la hoja de datos (PDF) - AMIC Technology

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A29DL322TV-80 Datasheet PDF : 50 Pages
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A29DL32x Series
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. Sector
protection and unprotection can be implemented via two
methods.
The primary method 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 23 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 sector unprotect algorithm unprotects all sectors in
parallel. All previously protected sectors must be individually
re-protected. To change data in protected sectors efficiently,
the temporary sector unprotect function is available. See
“Temporary Sector/Sector Block Unprotect”.
The alternate method for protection and unprotection is by
software sector /sector block protect unprotect command.
See Figure 2 for Command Flow.
The device is shipped with all sectors unprotected.
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 certain boot sectors 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 the two “outermost”
8 Kbyte boot sectors independently of whether those sectors
were protected or unprotected using the method described in
“Sector/Sector Block Protection and Unprotection”. The two
outermost 8 Kbyte boot sectors are the two sectors
containing the lowest addresses in a bottom-boot-configured
device, or the two sectors containing the highest addresses
in a top-boot-configured device.
If the system asserts VIH on the WP /ACC pin, the device
reverts to whether the two outermost 8 Kbyte boot sectors
were last set to be protected or unprotected. That is, sector
protection or unprotection for these two 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.
Temporary Sector/Sector Block 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 Tables 6 and 7).
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 VID
(8.5V-12.5V). 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 algorithm, and Figure 22 shows the timing
diagrams, for this feature.
PRELIMINARY (May, 2005, Version 0.0)
14
AMIC Technology, Corp.

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