W25Q256FVBIF-TR Datasheet, PDF (87/108 Pages) Winbond – 3V 256M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI

W25Q256FV
8.2.46 Enter QPI Mode (38h)
The W25Q256FV support both Standard/Dual/Quad Serial Peripheral Interface (SPI) and Quad
Peripheral Interface (QPI). However, SPI mode and QPI mode cannot be used at the same time. “Enter
QPI (38h)” instruction is the only way to switch the device from SPI mode to QPI mode.
Upon power-up, the default state of the device upon is Standard/Dual/Quad SPI mode. This provides full
backward compatibility with earlier generations of Winbond serial flash memories. See Instruction Set
Table 1-3 for all supported SPI commands. In order to switch the device to QPI mode, the Quad Enable
(QE) bit in Status Register-2 must be set to 1 first, and an “Enter QPI (38h)” instruction must be issued. If
the Quad Enable (QE) bit is 0, the “Enter QPI (38h)” instruction will be ignored and the device will remain
in SPI mode.
See Instruction Set Table 4-6 for all the commands supported in QPI mode.
When the device is switched from SPI mode to QPI mode, the existing Write Enable and Program/Erase
Suspend status, and the Wrap Length setting will remain unchanged.
/CS
CLK
Mode 3
Mode 0
DI
(IO₀)
DO
(IO₁)
0 1 2 3 4 5 6 7 Mode 3
Mode 0
Instruction (38h)
High Impedance
Figure 50. Enter QPI Instruction (SPI Mode only)
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Publication Release Date: February 11, 2015
Preliminary – Revision H