S29WSXXXN Datasheet, PDF (31/95 Pages) SPANSION – 256/128/64 Megabit (16/8/4 M x 16-Bit) CMOS 1.8 Volt-only Simultaneous Read/Write, Burst Mode Flash Memory

Preliminary
device. It is the software's responsibility to comprehend ramifications of loading a write-buffer
location more than once. The counter decrements for each data load operation, NOT for each
unique write-buffer-address location. 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/data write combinations will abort the Write Buffer Pro-
gramming operation. The device will then “go busy.” The Data Bar polling techniques should
be used while monitoring the last address location loaded into the write buffer. This eliminates
the need to store an address in memory because the system can load the last address loca-
tion, issue the program confirm command at the last loaded address location, and then data
bar poll at that same address. DQ7, DQ6, DQ5, DQ2, and DQ1 should be monitored to deter-
mine the device status during Write Buffer Programming.
The write-buffer “embedded” programming operation can be suspended using the standard
suspend/resume commands. Upon successful completion of the Write Buffer Programming
operation, the device will return to READ mode.
The Write Buffer Programming Sequence is ABORTED under any of the following conditions:
„ 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 selected 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, DQ5 = 0. This indicates that the Write Buffer Programming Oper-
ation was ABORTED. A “Write-to-Buffer-Abort reset” command sequence is required when
using the write buffer Programming features in Unlock Bypass mode. Note that the SecSI^TM
sector, autoselect, and CFI functions are unavailable when a program operation is in progress.
Write buffer programming is allowed in any sequence of memory (or address) locations.
These flash devices are capable of handling multiple write buffer programming operations on
the same write buffer address range without intervening erases. However, programming the
same word address multiple times without intervening erases requires a modified program-
ming method. Please contact your local Spansion^TM representative for details.
Use of the write buffer is strongly recommended for programming when multiple words are
to be programmed. Write buffer programming is approximately eight times faster than pro-
gramming one word at a time.
October 29, 2004 S29WSxxxN_00_F0
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