May 13, 2004 27631A4 S29GLxxxN MirrorBitTM Flash Family 61
Advance Information
Note that if a Write Buffer address location is loaded multiple times, the address/
data pair counter will be decremented for every data load operation. The host
system must therefore account for loading a write-buffer location more than
once. The counter decrements for each data load operation, not for each unique
write-buffer-address location. Note also that if an address location is loaded more
than once into the buffer, the final data loaded for that address will be
programmed.
Once the specified number of write buffer locations have been loaded, the system
must then write the Program Buffer to Flash command at the sector address. Any
other address and data combination aborts the Write Buffer Programming oper-
ation. The device then begins programming. Data polling should be used while
monitoring the last address location loaded into the write buffer. DQ7, DQ6, DQ5,
and DQ1 should be monitored to determine the device status during Write Buffer
Programming.
The write-buffer programming operation can be suspended using the standard
program suspend/resume commands. Upon successful completion of the Write
Buffer Programming operation, the device is ready to execute the next command.
The Write Buffer Programming Sequence can be aborted in the following ways:
Load a value that is greater than the page buffer size during the Number of
Locations to Program step.
Write to an address in a sector different than the one specified during the
Write-Buffer-Load command.
Write an Address/Data pair to a different write-buffer-page than the one se-
lected by the Starting Address during the write buffer data loading stage of
the operation.
Write data other than the Confirm Command after the specified number of
data load cycles.
The abort condition is indicated by DQ1 = 1, DQ7 = DATA# (for the last address
location loaded), DQ6 = toggle, and DQ5=0. A Write-to-Buffer-Abort Reset com-
mand sequence must be written to reset the device for the next operation. Note
that the full 3-cycle Write-to-Buffer-Abort Reset command sequence is required
when using Write-Buffer-Programming features in Unlock Bypass mode.
Write buffer programming is allowed in any sequence. Note that the SecSi sector,
autoselect, and CFI functions are unavailable when a program operation is in
progress. This flash device is capable of handling multiple write buffer program-
ming operations on the same write buffer address range without intervening
erases. For applications requiring incremental bit programming, a modified pro-
gramming method is required, please contact your local Spansion representative.
Any bit in a write buffer address range cannot be programmed from “0”
back to a “1.” Attempting to do so may cause the device to set DQ5 = 1, or
cause the DQ7 and DQ6 status bits to indicate the operation was successful. How-
ever, a succeeding read will show that the data is still “0.” Only erase operations
can convert a “0” to a “1.”
Accelerated Program
The device offers accelerated program operations through the WP#/ACC pin.
When the system asserts V
HH
on the WP#/ACC pin, the device automatically en-
ters the Unlock Bypass mode. The system may then write the two-cycle Unlock
Bypass program command sequence. The device uses the higher voltage on the
WP#/ACC pin to accelerate the operation. Note that the WP#/ACC pin must not
