E S I
E S I
ADVANCED INFORMATION
Excel Semiconductor inc.
be protected prior to the first sector unprotection
write cycle to avoid any over-erase due to the intrin-
sic erase characteristics of the protection cell. After
the unprotection operation, all previously protected
sectors will need to be individually re-protected.
Standard microprocessor bus cycle timings are used
in the unprotection and unprotect verification opera-
tions. Three unprotect methods are provided in the
ES29DL320 device. All unprotection and unprotect
verification cycles are summarized in detail at the
Table 1.
If the system asserts V on the WP#/ACC pin, the
IL
device disables program and erase functions in the
two “outermost” 8Kbytes boot sectors indepen-
dently of whether those sectors were protected or
unprotected using the method described in “Sector
Group Protection and Unprotection”. The two outer-
most of 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 V on the WP#/ACC pin, the
IH
-
-
-
In-system unprotection
A9 High-voltage unprotection
Temporary sector unprotection
device reverts to whether the two outermost 8
Kbyte boot sectors were last set to be protected or
unprotected. That is, sector protection or unprotec-
tion for these two sectors depends on whether they
were last protected or unprotected using the
method described in “Sector Group Protection and
Unprotection”.
In-System Unprotection
“In-system unprotection”, the primary method,
requires V (8.5V~12.5V) on the RESET# with
ID
Note that the WP#/ACC pin must not be left floating
or unconnected; inconsistent behavior of the device
may result.
A6=1, A1=1, and A0=0. This method can be imple-
mented either in-system or via programming equip-
ment. This method uses standard microprocessor
bus cycle timing. Refer to Fig. 29 for timing diagram
and Fig. 4 for the unprotection algorithm.
A9 High-Voltage Unprotection
START
“High-voltage unprotection”, the alternate method
intended only for programming equipment, must
RESET# = VID
(Note 1)
force V (8.5V~12.5V) on address pin A9 and con-
ID
trol pin OE# with A6=1, A1=1 and A0=0. Refer to
Fig. 32 for timing diagram and Fig. 6 for the unpro-
tection algorithm.
Perform Erase or
Program Operations
Temporary Sector Unprotect
This feature allows temporary unprotection of previ-
ously protected sectors to change data in-system.
The Sector Unprotect mode is activated by setting
RESET# = VIH
the RESET# pin to V (8.5V~12.5V). During this
ID
Temporary Sector
Unprotect Completed
(Note 2)
mode, formerly protected sectors can be pro-
grammed or erased by selecting the sector
addresses. Once V is removed from the RESET#
ID
pin, all the previously protected sectors are pro-
tected again. Fig. 1 shows the algorithm, and Fig. 27
shows the timing diagrams for this feature.
Notes:
1. All protected sectors are unprotected (If WP#/ACC = V ,
IL
outermost boot sectors will remain protected).
2. All previously protected sectors are protected once again.
WRITE PROTECT ( WP# )
The write protect function provides a hardware
method of protecting certain boot sectors without
Figure 1. Temporary Sector Unprotect
Operation
using V . This function is one of two provided by the
ID
WP#/ACC pin.
9
Rev. 0E May 25, 2006
ES29DL320
EXCELSEMI [ EXCEL SEMICONDUCTOR INC. ]
