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ECSPI Slave Mode TXFIFO problem

Question asked by chris_f on Oct 25, 2019
Latest reply on Nov 15, 2019 by chris_f

I'm having some trouble using the ECSPI on an i.MX6ULL in slave mode in a continuous streaming application.


Data received by the part is fine but I'm getting repetitions in the transmitted data i.e. words that have been written to ECSPI0_TXDATA only once are transmitted multiple times.


This post (Mailing List Archive: [PATCH v2 8/8] spi: imx: Add support for SPI Slave mode for imx53 and imx6 chips ) mentions a possible cause but I can't see it in errata.

1. ECSPI has a HW issue when works in Slave mode, after 64
words written to TXFIFO, even TXFIFO becomes empty,
ECSPI_TXDATA keeps shift out the last word data,
so we have to disable ECSPI when in slave mode after the
transfer completes

Does this mean:

a) if I never completely fill the TXFIFO it will be OK?

b) never fill and never let it completely empty?


Any suggestion for a work-around would be welcome.