Preliminary EN29GL064
A9.
Address pins must be as shown in Table 4.
•
To access Autoselect mode without using high voltage on A9, the host system must issue the
Autoselect command.
•
The Autoselect command sequence may be written to an address within a sector that is either in the
read or erase-suspend-read mode.
•
•
The Autoselect command may not be written while the device is actively programming or erasing.
The system must write the reset command to return to the read mode (or erase-suspend-read mode
if the sector was previously in Erase Suspend).
•
•
It is recommended that A9 apply VID after power-up sequence is completed. In addition, it is
recommended that A9 apply from VID to VIH/VIL before power-down the VCC / VIO.
When verifying sector protection, the sector address must appear on the appropriate highest order
address bits. The remaining address bits 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. The Autoselect codes can also be accessed in-system through the command register.
Program/Erase Operations
These devices are capable of several modes of programming and or erase operations which are
described in detail in the following sections.
During a write operation, the system must drive CE# and WE# to VIL and OE# to VIH when providing
address, command, and data. Addresses are latched on the last falling edge of WE# or CE#, while data
is latched on the 1st rising edge of WE# or CE#.
The Accelerated Program mode allows the host system to send program commands to the Flash device
without first writing unlock cycles within the command sequence.
Note the following:
•
•
When the Embedded Program algorithm is complete, the device returns to the read mode.
The system can determine the status of the program operation by reading the DQ status bits. Refer
to the Write Operation Status on page 20 for information on these status bits.
An “0” cannot be programmed back to a “1.” A succeeding read shows that the data is still “0.”
Only erase operations can convert a “0” to a “1.”
•
•
•
Any commands written to the device during the Embedded Program/Erase are ignored except the
Suspend commands.
•
•
Secured Silicon Sector, Autoselect, and CFI functions are unavailable when a program operation is
in progress.
A hardware reset and/or power removal immediately terminates the Program/Erase operation and
the Program/Erase command sequence should be reinitiated once the device has returned to the
read mode to ensure data integrity.
•
•
Programming is allowed in any sequence and across sector boundaries for single word programming
operation.
Programming to the same word address multiple times without intervening erases is permitted.
Single Word Programming
Single word programming mode is one method of programming the Flash. In this mode, four Flash
command write cycles are used to program an individual Flash address. The data for this programming
operation could be 8 or 16-bits wide.
While the single word programming method is supported by most devices, in general Single Word
Programming is not recommended for devices that support Write Buffer Programming.
When the Embedded Program algorithm is complete, the device then returns to the read mode and
addresses are no longer latched. The system can determine the status of the program operation by
reading the DQ status bits.
•
•
During programming, any command (except the Suspend Program command) is ignored.
The Secured Silicon Sector, Autoselect, and CFI functions are unavailable when a program
operation is in progress.
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.eonssi.com
19
Rev. A, Issue Date: 2009/3/20
EON [ EON SILICON SOLUTION INC. ]
