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Numonyx <strong>Wireless</strong> <strong>Flash</strong> <strong>Memory</strong> (<strong>W30</strong>)<br />
11.0 Program Operations<br />
11.1 Word Program<br />
When the Word Program command is issued, the WSM executes a sequence of<br />
internally timed events to program a word at the desired address, and to verify that the<br />
bits are sufficiently programmed. Programming the flash memory array changes<br />
specifically addressed bits to 0; 1 bits do not change the memory cell contents.<br />
Programming can occur in only one partition at a time. All other partitions must be in<br />
either a read mode or erase suspend mode. Only one partition can be in erase suspend<br />
mode at a time.<br />
To examine the status register can be examined for program progress, read any<br />
address within the partition that is busy programming. However, while most status<br />
register bits are partition-specific, the Device WSM Status bit, SR[7], is device-specific.<br />
That is, if the status register is read from any other partition, SR[7] indicates the<br />
program status of the entire flash memory device. This status bit permits the system<br />
CPU to monitor the program progress while reading the status of other partitions.<br />
CE# or OE# toggle (during polling) updates the status register. Several commands can<br />
be issued to a partition that is programming: Read Status Register, Program Suspend,<br />
Read Identifier, and Read Query. The Read Array command can also be issued, but the<br />
read data is indeterminate.<br />
After programming completes, three status register bits can signify various possible<br />
error conditions:<br />
• SR[4] indicates a program failure if set.<br />
• If SR[3] is set, the WSM could not execute the Word Program command, because VPP was outside the acceptable limits.<br />
• If SR[1] is set, the program was aborted, because the WSM attempted to program<br />
a locked block.<br />
After the status register data is examined, clear it using the Clear Status Register<br />
command before issuing a new command. The partition remains in status register<br />
mode until another command is written to that partition. Any command can be issued<br />
after the status register indicates program completion.<br />
If CE# is deasserted while the flash device is programming, the flash devices do not<br />
enter standby mode until the program operation completes.<br />
November 2007 Datasheet<br />
Order Number: 290702-13 59
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