PC48F4400P0VB0 datasheet(59/102 Pages) NUMONYX

59 / 102 page

November 2007

Datasheet

Order Number: 290701-18

Numonyx™ Wireless Flash Memory (W18)

11.0

Program Operations

11.1

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 VPP 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.

PC48F4400P0VB0 Datasheet(PDF) 59 Page - Numonyx B.V