How to use PDM and MQS signals on a IMX8M-PLUS

We would like to use the PDM (all 5 signals) and MQS (one of them is enough) signals. But these signals and the peripherals they belong too are not listed in any document of the SOM or Carrier board.
And the Pinout Designer also does not mention these signals.

Can we not use them?

Hello @simmania,

Thanks for reaching out to the Toradex Community.
May I ask you to provide us with some more information that would help us to get started with:

  1. Which version of verdin iMX8M-Plus and which carrier board are you using?
  2. Are you using one of our Yocto-based reference images or TorizonCore or a custom-built image? Could you please also mention the version of the image?

We are investigating if we can use the Toradex modules. So we did not yet select a module. But it need to a IMX8M-PLUS device.
Also the Carrier board is not yet selected. It will depend on the answer of this question. Thus which carrier board should we use if we want to use the PMD signals.

This is a block diagram of what we want:

We want to create an custom expansion board that connects to all the peripherals on the M-core side.

OS is also not decided. I think we prefer Torizon. As little as customization as possible.

According to the Verdin iMX8MP datasheet:

5.15.3 PDM Microphone Interface
The i.MX 8M Plus SoC features up to four PDM microphone input signals. PDM stands for PulseDensity Modulation and is a popular digital interface for delivering audio from microphones to the SoC. The PDM bitstream is time-multiplexed and contains audio information in two channels (left and right). This means a total of eight microphones can be attached to the PDM interface of the i.MX 8M Plus. Since the PDM is not a standard interface of Verdin, these signals are available only as alternate functions. Therefore, the PDM microphone interface is not guaranteed to be compatible with other Verdin Modules.

Could you please provide clarification on the meaning of the abbreviation “MQS”? I have come across 23 possible meanings for MQS, and I am still uncertain about the nature of MQS signals.

Using the table in the Verdin iMX8M Plus data sheet and checking only the X1 pins that are routed to the expansion headers on the Dahlia carrier board, I could find out that not all PDM signals are available. There are also not enough pins for all the other functions we need.
I will check the other carrier board, but it is a bit to big for us.

The MQS signal is a mistake. It is present on some other NXP processor chip which we also investigated. It does not exist on the IMX8M-PLUS. Sorry for that.

All available PDM pins listed here:

The primary recommended approach for using a Toradex modules is to design a custom carrier board that meets your specific requirements and includes all the necessary peripherals. However, for prototyping purposes, you can use the carrier board provided by Toradex. The Verdin Development board conveniently routes all the required signals to external connectors. Please be aware that all Toradex carrier board designs are open source, and you are free to use them as a foundation for your own custom design. Additionally, we recommend referring to our Carrier board design guides for further assistance.

Hello @simmania ,
Is your issue solved with the info provided by @alex.tx? If so, could you please mark the most suitable answer as solution?

Best regards,