AUD4 IOMUX question

Hi, we are developing the sgtl5000 driver for QNX and we want to measure the I2S signals (AUD4) on the X1 connector, we are not sure how IOMUX works, different PAD are used for external AUD4 signal ?. for example AUD4_TXC (TXC) DISP0_DAT20 ALT3 is use for on board sgtl5000, external AUD4 TXC is routed in SD2_DAT3 ALT3?
For measurement purposes, are the signal not available on X1?

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Hi @marianoT

The IO multiplexer in the SoC officially does not support enabling simultaneously an interface signal on multiple output pins. However, theoretically, it should be possible to enable the output signals on both SoC pins, the one connected to the on-module audio codec as well as the one connected to the module edge connector. It is definitely not recommended by NXP, but it should work. This is only applicable to the output signals. The input signals cannot be multiplexed simultaneously to two SoC pin. Please also have a look into the Pinout Designer Tool. The tool features a help file which further explains how IO multiplexing works.

On the other hand, it is probably easier and saver to measure the signals directly on the audio codec. You will find the pinout of the codec in the datasheet of the SGTL5000.