IMX7D Qspi change clock issue

[xujibin]

I used a serial flash on IMX7D target board, when the spi clcok is 29M, It works well, but when I change it to 84M, read data error,IF I write data at 84M and read it at 29M, it is ok. But if 84M write data and 84M read data, It faild. So ,if I change the spi clock frequence, what  othre parameters in qspi controller should I change at the same time ?

[igorpadykov]

Hi xu

please check sect.4.10.11 QUAD SPI (QSPI) Timing Parameters i.MX7D Datasheet

http://cache.nxp.com/files/32bit/doc/data_sheet/IMX7DCEC.pdf

and i.MX7D Reference Manual sect.10.2 Quad Serial Peripheral Interface (QuadSPI)

http://cache.nxp.com/files/32bit/doc/ref_manual/IMX7DRM.pdf

Best regards
igor
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[xujibin]

Thank you very much, I read http://cache.nxp.com/files/32bit/doc/data_sheet/IMX7DCEC.pdf,

in the page of 109 of IMX7DCEC.pdf, accroding to table 84, the Tck(SCK clock period) min value

is 20 ns, so I think the max SCK clock frequence  is 50M HZ,

If I change SCK clock to 90, it will not work ?

expect your replay.

[igorpadykov]

seems table 84 is for other module,

please look at sect.4.10.11 QuadSPI (QSPI) timing parameters

you are right SCK max. clock frequence (QuadSPI DDR mode) is 50MHz, it will not work with  90MHz.

Best regards
igor

[xujibin]

Ok, thank you!