EN29LV320A
sector protection, the sector address must appear on the appropriate highest order address bits. Refer to
the corresponding Sector Address Tables. The “Command Definitions” table shows the remaining
address bits that are don’t-care. When all necessary bits have been set as required, the programming
equipment may then read the corresponding identifier code on DQ15–DQ0.
To access the autoselect codes in-system; the host system can issue the autoselect command via the
command register, as shown in the Command Definitions table. This method does not require VID. See
“Command Definitions” for details on using the autoselect mode.
Writing Command Sequences
To write a command or command sequence to program data to the device or erase data, the system has
to drive WE# and CE# to VIL, and OE# to VIH.
For program operations, the BYTE# pin determines whether the device accepts program data in bytes or
words. An erase operation can erase one sector or the whole chip.
The system can also read the autoselect codes by entering the autoselect mode, which need the
autoselect command sequence to be written. Please refer to the “Command Definitions” for all the
available commands.
RESET#: Hardware Reset
When RESET# is driven low for tRP, all output pins are tristates. All commands written in the internal state
machine are reset to reading array data.
Please refer to timing diagram for RESET# pin in “AC Characteristics”.
Sector/Sector Group Protection & Chip Unprotection
The hardware sector group protection feature disables both program and erase operations in any sector. The
hardware chip unprotection feature re-enables both program and erase operations in previously protected
sectors. A sector group implies three or four adjacent sectors that would be protected at the same time. Please
see the following tables which show the organization of sector groups.
There are two methods to enable this hardware protection circuitry. The first one requires only that the
RESET# pin be at VID and then standard microprocessor timings can be used to enable or disable this
feature. See Flowchart 7a and 7b for the algorithm and Figure. 12 for the timings.
When doing Chip Unprotect, all the unprotected sector groups must be protected prior to any unprotect
write cycle.
The second method is for programming equipment. This method requires VID to be applied to both OE#
and A9 pins and non-standard microprocessor timings are used. This method is described in a separate
document named EN29LV320A Supplement, which can be obtained by contacting a representative of Eon
Silicon Solution, Inc.
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.essi.com.tw
13
Rev. B, Issue Date: 2007/07/17
EON [ EON SILICON SOLUTION INC. ]
