SAI questions for i.MX8M Plus

[jimmyli]

Hi,

     We are designing our production with i.mx8m plus, and some questions about sai that hope you can help us to check them.

     1>block diagram

         

     2>questions

     a. sai master mode in i.mx8m plus #1(sai1+sai2+sai5), how to config the external clk to mclk ?

         does it has special requirement for external clk ?

     b. sai slave mode in i.mx8m plus #2(sai5), does it support ? if yes, how to config?

Thanks very much.

[JosephAtNXP]

Hi, Jimmy

I've checked that the Master Clock is added for oversampling and its sources can be internal references with fractional dividers (this is the cost-effective option) and external oscillators, that I think that may reduce your costs (to maximize performance) and is an optional signal to the slave.

The masterclock has to be a multiple of the different frequencies used for example in a same SAI both duplex and I think that that matches to different SAIs with both duplex.

I think that the BD can be simplified to a simple oscillator in the master clock source and its distribution can be simplified removing the slave master feeding.

To enable clocks, I found a document that contextualize different things, the answer is to modify the register SAI Receive Configuration 2 Register (RCR2) and to enable the pin muxing desired using config tools. Read the document as a design guide with the interface https://www.nxp.com/docs/en/application-note/AN12202.pdf

Thank you! Hope this helps

[jimmyli]

Hi josephlinares,

      Thanks for the helpful message.

      We will try and update if any unclear.

      Thanks again.

[JosephAtNXP]

Hi,

I'm pleased to hear it, please update

Regards