topic Re: Does IMX8MP support SAI1 TXFS/RXFS=512KHz, TXC/RXC=32.768MHz? in i.MX Processors

Does IMX8MP support SAI1 TXFS/RXFS=512KHz, TXC/RXC=32.768MHz?

Takashi_Kashiwagi — Wed, 25 Oct 2023 06:41:58 GMT

Hi Community.

We have using IMX8MP with yocto (kernel 5.15).

We will be using SAI1 with the following settings. I would like to ask a question because there is something in the data sheet that I don't understand.

TXFS/RXFS=512KHz, TXC/RXC=32.768MHz (External FPGA provides these clocks)

Q. On page 79 of the datasheet (i.MX 8M Plus Applications Processor Datasheet for Industrial Products, Rev. 2.1), there was a note regarding SAI as shown below. We are planning to use TXC/RXC=32.768MHz, Is this condition supported?

TX does not support 50 MHz operation in Slave mode. To achieve 50 MHz BCLK in RX, configure BCI=1 in SAI TCR2
register and FSD=0 in SAI TCR4 register.

Re: Does IMX8MP support SAI1 TXFS/RXFS=512KHz, TXC/RXC=32.768MHz?

Sanket_Parekh — Thu, 26 Oct 2023 05:02:37 GMT

Hello @Takashi_Kashiwagi,

I hope you are doing well.

This means that if one is using the SAI in slave mode and you are using an external clock source that is 50 mhz, one will need to configure the SAI to use a different clock frequency.

Please refer to the datasheet and set the following values in the SAI registers as given below.
SAI_TCR2 = 1
SAI_TCR4 = 0

I have shared a reference link for the reference, Please refer to that, It will be helpful.
https://community.nxp.com/t5/i-MX-Processors/External-clock-that-provide-root-clock-for-SAI3-and-SPDIF/m-p/1019821

Thanks & Regards,
Sanket Parekh

Re: Does IMX8MP support SAI1 TXFS/RXFS=512KHz, TXC/RXC=32.768MHz?

Takashi_Kashiwagi — Fri, 27 Oct 2023 04:56:21 GMT

Hi Sanket-san

Thank you for reply!

Let me confirm

> This means that if one is using the SAI in slave mode and you are using an external clock source that is 50 mhz, one will need to configure the SAI to use a different clock frequency.

If the clock is less than 50MHz(ex. 32.768MHz), I don't need to change the SAI settings, right?

Best Regards,

KASHIWAGI Takashi

Re: Does IMX8MP support SAI1 TXFS/RXFS=512KHz, TXC/RXC=32.768MHz?

Sanket_Parekh — Fri, 27 Oct 2023 05:20:59 GMT

Hello @Takashi_Kashiwagi,

I hope you are doing well.

Yes, For the same please refer to this below thread, It will be helpful.
https://community.nxp.com/t5/i-MX-Processors/CCM-Changing-clock-parent-freezes-system/m-p/851562

Thanks & Regards,
Sanket Parekh