1.8 Volt Intel®Wireless Flash Memory with 3 Volt I/O
Datasheet 31
6.0 Program and Erase Operations
6.1 Program/Erase Suspend and Resume
The Program Suspend and Erase Suspend commands halt an in-progress program or erase
operation. The command can be issued at any device address. The partition corresponding to the
command’s address remains in its previous state. A suspend command allows data to be accessed
from memory locations other than the one being programmed or the block being erased.
A program operation can be suspended only to perform a read operation. An erase operation can be
suspended to perform either a program or a read operation within any block, except the block that
is erase suspended. A program command nested within a suspended erase can subsequently be
suspended to read yet another location. Once a program or erase process starts, the Suspend
command requests that the WSM suspend the program or erase sequence at predetermined points
in the algorithm. The partition that is actually suspended continues to output status register data
after the Suspend command is written. An operation is suspended when status bits SR[7] and SR[6]
and/or SR[2] are set.
To read data from blocks within the partition (other than an erase-suspended block), you can write
a Read Array command. Block erase cannot resume until the program operations initiated during
erase suspend are complete. Read Array, Read Status Register, Read Identifier (ID), Read Query,
and Program Resume are valid commands during Program or Erase Suspend. Additionally, Clear
Status Register, Program, Program Suspend, Erase Resume, Lock Block, Unlock Block, and Lock-
Down Block are valid commands during erase suspend.
To read data from a block in a partition that is not programming or erasing, the operation does not
need to be suspended. If the other partition is already in read array, ID, or Query mode, issuing a
valid address returns corresponding data. If the other partition is not in a read mode, one of the read
commands must be issued to the partition before data can be read.
During a suspend, CE# = VIH places the device in standby state, which reduces active current. VPP
must remain at its program level and WP# must remain unchanged while in suspend mode.
A resume command instructs the WSM to continue programming or erasing and clears status
register bits SR[2] (or SR[6]) and SR[7]. The Resume command can be written to any partition.
When read at the partition that is programming or erasing, the device outputs data corresponding to
the partition’s last mode. If status register error bits are set, the status register can be cleared before
issuing the next instruction. RST# must remain at VIH.SeeFigure 7, “Program Suspend / Resume
Flowchart” on page 32,andFigure 8, “Erase Suspend / Resume Flowchart” on page 33.
If a suspended partition was placed in read array, read status register, read identifier (ID), or read
query mode during the suspend, the device remains in that mode and outputs data corresponding to
that mode after the program or erase operation is resumed. After resuming a suspended operation,
issue the read command appropriate to the read operation. To read status after resuming a
suspended operation, issue a Read Status Register command (70h) to return the suspended partition
to status mode.
A minimum tWHWH time should elapse between an Erase command and a subsequent Erase
Suspend command to ensure that the device achieves sufficient cumulative erase time. Occasional
Erase-to-Suspend interrupts do not cause problems, but Erase-to-Suspend commands issued too
frequently may produce unexpected results.