5.39 Write Suspend (SUS) and Write Resume (RES)

Write Suspend allows a Sector Erase, Block Erase, or Page Program operation to be temporarily interrupted so that data can be erased, programmed, or read in another area of memory. The suspended operation can be resumed using the Write Resume command. This functionality is supported in both SPI and QPI modes.

Only one write operation can be suspended at a time. If an operation is already suspended, any additional Write Suspend commands are ignored. Write Suspend commands issued during a Chip Erase operation are also ignored, as Chip Erase is not permitted while a write is suspended. In addition, the Write Resume command is ignored until any program or erase operation initiated during the suspended state has completed. A minimum interval of T_LRS (1000 μs) is required between a Write Resume command and the next Write Suspend command.

To initiate a Write Suspend operation, the host drives CE# low, issues the SUS command (75h) in SPI or QPI mode, and then drives CE# high. The suspension of the program or erase operation is indicated in Status Register 2 when the SUS bit changes from 0 to 1.