6.4 Write STATUS Register (WRSR)

The Write STATUS Register (WRSR) instruction enables the SPI host to change selected bits of the STATUS register. Before a WRSR instruction can be initiated, a WREN instruction must be executed to set the WEL bit to logic ‘1’. Upon completion of a WREN instruction, a WRSR instruction can be executed.

Note: The WRSR instruction has no effect on bit 6, bit 5, bit 4, bit 1 or bit 0 of the STATUS register. Only bit 7, bit 3 and bit 2 can be changed using the WRSR instruction. These modifiable bits are the Write-Protect Enable (WPEN) bit and the Block Protect (BP1, BP0) bits. These three bits are nonvolatile bits and have the same properties and functions as regular EEPROM cells. Their values are retained when power is removed from the device.
The AT25080B/AT25160B will not respond to commands other than RDSR following a WRSR instruction until the self‑timed internal write cycle has completed. When the write cycle is completed, the WEL bit in the STATUS register is reset to logic ‘0’.
Figure 6-4. WRSR Waveform
Note:
  1. This instruction initiates a self-timed internal write cycle (tWC) on the rising edge of CS after a valid sequence.