Numonyx™ StrataFlash® Embedded Memory (P33)
stored to sequential buffer locations starting at address 0x00. Programming of the
buffer contents to the flash memory array starts as soon as the buffer is full. If the
number of words is less than 32, the remaining buffer locations must be filled with 0xFFFF.
Caution:
The buffer must be completely filled for programming to occur. Supplying an
address outside of the current block's range during a buffer-fill sequence
causes the algorithm to exit immediately. Any data previously loaded into the
buffer during the fill cycle is not programmed into the array.
The starting address for data entry must be buffer size aligned, if not the BEFP
algorithm will be aborted and the program fails and (SR[4]) flag will be set.
Data words from the write buffer are directed to sequential memory locations in the
flash memory array; programming continues from where the previous buffer sequence
ended. The host programming system must poll SR[0] to determine when the buffer
program sequence completes. SR[0] cleared indicates that all buffer data has been
transferred to the flash array; SR[0] set indicates that the buffer is not available yet for
the next fill cycle. The host system may check full status for errors at any time, but it is
only necessary on a block basis after BEFP exit. After the buffer fill cycle, no write
cycles should be issued to the device until SR[0] = 0 and the device is ready for the
next buffer fill.
Note:
Any spurious writes are ignored after a buffer fill operation and when internal program
is proceeding.
The host programming system continues the BEFP algorithm by providing the next
group of data words to be written to the buffer. Alternatively, it can terminate this
phase by changing the block address to one outside of the current block’s range.
The Program/Verify phase concludes when the programmer writes to a different block
address; data supplied must be 0xFFFF. Upon Program/Verify phase completion, the
device enters the BEFP Exit phase.
11.3.3.4
11.3.4
BEFP Exit Phase
When SR[7] is set, the device has returned to normal operating conditions. A full status
check should be performed at this time to ensure the entire block programmed
successfully. When exiting the BEFP algorithm with a block address change, the read
mode will not change. After BEFP exit, any valid command can be issued to the device.
Program Suspend
Issuing the Program Suspend command while programming suspends the
programming operation. This allows data to be accessed from the device other than the
one being programmed. The Program Suspend command can be issued to any device
address. A program operation can be suspended to perform reads only. Additionally, a
program operation that is running during an erase suspend can be suspended to
perform a read operation (see Figure 34, “Program Suspend/Resume Flowchart” on
page 70).
When a programming operation is executing, issuing the Program Suspend command
requests the WSM to suspend the programming algorithm at predetermined points. The
device continues to output Status Register data after the Program Suspend command is
issued. Programming is suspended when Status Register bits SR[7,2] are set. Suspend
latency is specified in Section 7.5, “Program and Erase Characteristics” on page 39.
To read data from the device, the Read Array command must be issued. Read Array,
Read Status Register, Read Device Identifier, CFI Query, and Program Resume are valid
commands during a program suspend.
November 2007
Order Number: 314749-05
Datasheet
61
NUMONYX [ NUMONYX B.V ]
