IMXRT1052 SPDIF txClkSource tx_clk1 (from SAI1) not work

[vega_sdr]

Hi !

With XTALOSC and SPDIF0_CLK_ROOT clock source SPDIF transmitter work fine.

But when I select spdif_config.txClkSource = 2U//txClk from SAI1 for SPDIF, SPDIF not work.

SAI1 clock source - audiopll or ext mclk, I see all clock and data on SAI1 pins.

[vega_sdr]

Thanks a lot !

My mistake was that I didn't activate synchronous mode for sai_rx (I2S_RCR2_SYNC bit), in my project I use only sai_tx.

[kerryzhou]

Thanks for your updated information.

So, if you don't use SAI rx, it's better your SPDIF still use the SPDIF clock source :SPDIF0_CLK_ROOT.

Best Regards,

Kerry

[vega_sdr]

SAI1 and SPDIF must use external clock, but on my pcb it traced only to SAI1_mclk pin.

[kerryzhou]

Hi @vega_sdr 

  Do you configure the same sai1 clock to your SPDF0_CLK clock?

I mean, set your SAI1 clock the same frequency to your working SPDIF0_CLK_ROOT, whether this method works or not?

You can use the mcuxpresso project, cfg tool to configure the clock directly to test it.

Best Regards,

Kerry

[vega_sdr]

I set same clockPLL4_MAIN_CLK for SAI1_CLK and for SPDF0_CLK.

SPDIF work  when spdif_config.txClkSource = 1 and not work when spdif_config.txClkSource = 2

[kerryzhou · Accepted solution]

Hi @vega_sdr ,

   Seems my previous understanding is not correct. It is not the SAI ROOT clock, it is the sai rxbclk.

2 is the txclk1, from the above picture, it is the rxbclk.

So, do you check the RXBCLK, whether that have wave or not?

Best Regards,

kerry