SAI1多路输入输出问题

[eddylin]

从参考手册看到SAI1的TX和RX的复用配置如下：

现在我需要4路输入和4路输出都使用，应该如何配置？尝试过这些引脚都配置成ALT3，之后测试输出，如GPIO_B0_12和GPIO_SD_B1_02会同时输出通道1的数据，哪如何才能让其中一个接收通道3的数据？

[jimmychan]

How many channel of stereo data you need?

basically, support 4 channels. If TDM used, up to 8 channels.

For your reference：

https://www.nxp.com/docs/en/application-note/AN12090.pdf

[eddylin]

I need SAI1 to connect to 4 PCM Codec(4 RX and 4 TX).

I want to config GPIO_B0_12 as TX_DATA1 and GPIO_SD_B1_02 as RX_DATA3.

but actually when I enable txchn1 and send data,TX_DATA1 and GPIO_SD_B1_02 output txchn1 data at the same time.It seems that two pins is used as TX_DATA1.

Pin related configuraions as below:

SW_MUX_CTL_PAD_GPIO_B0_12:0x00000013
SW_MUX_CTL_PAD_GPIO_SD_B1_02:0x00000013
SAI1_RX_DATA3_SELECT_INPUNT:0x00000001

RCR3:0x00080000

what's wrong with it?

[jimmychan]

According to the IOMUXC_SAI1_RX_DATA3_SELECT_INPUT field descriptions, the DAISY should be '0' if you select the GPIO_SD_B1_02_ALT3 as an input.

[eddylin]

Thanks for your reply.Even though IOMUXC_SAI1_RX_DATA3_SELECT_INPUT configuration is wrong,Tx data in channel one should not be outputted through GPIO_SD_B1_02 and GPIO_B0_12 at the same time. One pin might be TX_DATA1,the other pin might be RX_DATA3.

I can not find the solution to using TX_DATA1 and RX_DATA3 at the same time until now.I going to use Flexio.Thanks anyway.