Numonyx™ Wireless Flash Memory (W18)
11.0
11.1
Program Operations
Word Program
When the Word Program command is issued, the WSM executes a sequence of
internally timed events to program a word at the desired address and verify that the
bits are sufficiently programmed. Programming the flash array changes specifically
addressed bits to 0; 1 bits do not change the memory cell contents.
Programming can occur in only one partition at a time. All other partitions must be in
either a read mode or erase suspend mode. Only one partition can be in erase suspend
mode at a time.
The Status Register can be examined for program progress by reading any address
within the partition that is busy programming. However, while most Status Register bits
are partition-specific, the Device WSM Status bit, SR[7], is
device-specific;
that is, if
the Status Register is read from any other partition, SR[7] indicates program status of
the entire device. This permits the system CPU to monitor program progress while
reading the status of other partitions.
CE# or OE# toggle (during polling) updates the Status Register. Several commands can
be issued to a partition that is programming: Read Status Register, Program Suspend,
Read Identifier, and Read Query. The Read Array command can also be issued, but the
read data is indeterminate.
After programming completes, three Status Register bits can signify various possible
error conditions. SR[4] indicates a program failure if set. If SR[3] is set, the WSM
couldn’t execute the Word Program command because V
PP
was outside acceptable
limits. If SR[1] is set, the program was aborted because the WSM attempted to
program a locked block.
After the Status Register data is examined, clear it with the Clear Status Register
command before a new command is issued. The partition remains in Status Register
mode until another command is written to that partition. Any command can be issued
after the Status Register indicates program completion.
If CE# is deasserted while the device is programming, the devices will not enter
standby mode until the program operation completes.
November 2007
Order Number: 290701-18
Datasheet
59
NUMONYX [ NUMONYX B.V ]
