topic LS1046 Configure QSPI for dual mode in Layerscape

LS1046 Configure QSPI for dual mode

kzambrano — Thu, 23 Aug 2018 13:08:09 GMT

Hi,

Was wanting to configure the QSPI to use only 2 data lines. Per the LS1046ARM spec, Chp 27, this is possible. Looking at section 3.4.7, the IFC word can be modified to reconfigure the pins in the RCW. Need some help understanding the encoding of this configuration and how to modify it in the RCW. Thanks.

Re: LS1046 Configure QSPI for dual mode

Pavel — Fri, 24 Aug 2018 04:26:01 GMT

Look at the following application note about QSPI using:

https://www.nxp.com/docs/en/application-note/AN4512.pdf

The Look-up Table register (QuadSPI_LUTn) is used for for setting Single, Dual or Quad I/O mode. See the Section 3.1.2 of the AN4512 and find the "Read from flash in Dual SDR Mode" in this Application Note.

Use PBL for setting QuadSPI_LUTn for this mode.

Have a great day,
Pavel Chubakov

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Re: LS1046 Configure QSPI for dual mode

kzambrano — Mon, 27 Aug 2018 12:53:59 GMT

Thanks Pavel,

Per the spec, QSPI comes up in single mode, however I don't see anything in the PBL taking it out of this mode. Further, in UBOOT, it appears that single mode is preserved. Would you be able to confirm this?

Re: LS1046 Configure QSPI for dual mode

kzambrano — Fri, 31 Aug 2018 15:45:33 GMT

I guess it's official. No RCW for QSPI to modify data lines so they stay in single mode until the kernel takes over.