AT25SL321 datasheet(53/82 Pages) RENESAS

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DS-AT25SL321-112 Rev. J

Page 53

Nov 1, 2022

AT25SL321 Datasheet

8.29 Enable QPI (38h)

The AT25SL321 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. Enable QPI command is

the only way to switch the device from SPI mode to QPI mode.

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 command must be issued. If the Quad Enable (QE) bit is 0, the Enable QPI command is

ignored and the device remains in SPI mode.

After power-up, the default state of the device is SPI mode. See the Command Set Table 6 for all the commands

supported in SPI mode and the Command Set Table 9 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 remains unchanged.

Figure 49. Enable QPI Command (SPI Mode only)

8.30 Disable QPI (FFh)

By issuing Disable QPI (FFh) command, the device switches back to SPI mode. When the device is switched

from QPI mode to SPI mode, the existing Write Enable Latch (WEL) and Program/Erase Suspend status, and the

Wrap Length setting remain unchanged.

Figure 50. Disable QPI Command for QPI Mode

246

Mode 3

Mode 0

Mode 3

Mode 0

High-Impedance

SCK

Command (38h)

SCK

Command

(FFh)

Mode 3

Mode 0

Mode 3

Mode 0

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