W25Q64DW Datasheet, PDF (65/82 Pages) Winbond – 1.8V 64M-BIT SERIAL FLASH MEMORY WITH DUAL/QUAD SPI & QPI

W25Q64DW
10.2.40 Enable QPI (38h)
The W25Q64DW support both Standard/Dual/Quad Serial Peripheral Interface (SPI) and Quad
Peripheral Interface (QPI). However, SPI mode and QPI mode can not be used at the same time. “Enable
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 Intruction 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 “Enable QPI (38h)” instruction must be issued.
If the Quad Enable (QE) bit is 0, the “Enable QPI (38h)” instruction will be ignored and the device will
remain in SPI mode.
See Instruction Set Table 4 for all the commands supported in QPI mode.
When the device is switched from SPI mode to QPI mode, the exsiting 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)
01234567
Instruction (38h)
Mode 3
Mode 0
High Impedance
Figure 39. Enable QPI Instruction (SPI Mode only)
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Publication Release Date: January 13, 2011
Preliminary - Revision C