New board, pinout help requested

Technical Support
,
1

I am looking at using the Verdin iMX8M Plus Quad 2GB Wi-Fi / Bluetooth IT V1.1A SOM in a new project. I want to expose SAI pins.

  • SAI_MCLK
  • SAI_TX_BCLK
  • SAI_TX_DATA0
  • SAI_TX_DATA1
  • SAI_TX_SYNC

From the pinout tool, I can see I have options:

  • DIGITAL_AUDIO_1_SAI
  • DIGITAL_AUDIO_2_SAI
  • DIGITAL_AUDIO_3_SAI

Four questions:

  1. Is there an easier way to track down whether those pins are available on-board headers than searching the datasheet for SODIMM pins?
  2. I think not, but is there a way to expose these 5 pins on a pin header, not the X17 MIPI DSI header? I’m pretty sure every combination I tried failed with at least one pin ending up on the DSI header
  3. Is there an off-the-shelf board that accepts the cable from the X17 connector, and exposes header pins, pads, etc?
  4. Do one of the other carrier boards provide all 5 of these pins on header pins or pads?
2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

Based on the Verdin iMX8M Plus V1.1 datasheet, I can help answer your questions about exposing SAI pins for your project.

SAI Pin Availability Analysis

Looking at the datasheet’s Table 55: Standard Digital Audio Port Signals, the Verdin iMX8M Plus provides two standard I2S interfaces that are compatible with other modules(1):

I2S_1 (SAI1) Interface:

  • Pin 36: I2S_1_D_IN (SAI1_RX_DATA0)
  • Pin 34: I2S_1_D_OUT (SAI1_TX_DATA0)
  • Pin 32: I2S_1_SYNC (SAI1_TX_SYNC)
  • Pin 30: I2S_1_BCLK (SAI1_TX_BCLK)
  • Pin 38: I2S_1_MCLK (SAI1_MCLK)(1)

I2S_2 (SAI3) Interface:

  • Pin 48: I2S_2_D_IN (SAI3_RX_DATA0)
  • Pin 46: I2S_2_D_OUT (SAI3_TX_DATA0)
  • Pin 44: I2S_2_SYNC (SAI3_TX_SYNC)
  • Pin 42: I2S_2_BCLK (SAI3_TX_BCLK)(1)

Answering Your Questions

1. Easier Pin Tracking

The datasheet is indeed the authoritative source for pin mapping. The Table 17: SoC Pins Mapping in the V1.1 datasheet provides comprehensive pin multiplexing information(2). While the Pinout Designer tool helps visualize options, the datasheet tables remain essential for detailed pin assignments.

2. Pin Header Availability

Based on the pin assignments shown in the datasheet, the standard I2S signals (I2S_1 and I2S_2) are available on the main X1 connector pins, not exclusively on the X17 MIPI DSI header(1). However, some additional SAI instances may require alternate function configurations that could conflict with other interfaces.

3. Off-the-Shelf Breakout Solutions

The Zinnia Carrier Board is mentioned as a full-featured carrier board that provides access to most Verdin SoM interfaces and is intended as a production platform(3). While the documentation indicates it’s designed to expose module interfaces, specific details about SAI pin access on standard headers are not fully detailed in the available sources.

Recommendation

For your specific requirements with 5 SAI pins (MCLK, TX_BCLK, TX_DATA0, TX_DATA1, TX_SYNC), I recommend:

  1. Use the standard I2S_1 interface which provides 4 of your required signals on standard X1 pins
  2. Check if TX_DATA1 can be accessed through alternate SAI1 functions
  3. Consider the Zinnia Carrier Board as it’s specifically designed as a production platform with comprehensive interface access

To get precise information about pin availability on specific carrier boards and any available breakout solutions, I recommend using the tdx-info command on your system and checking the detailed carrier board documentation at Getting Device Information with Tdx-Info | Toradex Developer Center

Best regards, Toradex AI Assistant.

Did you like my answer? :+1: :-1:

If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.

3

Yes, all the required information is provided in the SOM datasheet, specifically in Chapter 5.15, Digital Audio Interfaces.

All the pins are exposed on the module’s X1 connector. There is no X17 header on the SOM itself. I assume you are referring to a carrier board. Since you did not specify which carrier board you are using, I cannot provide further assistance with that part of your question.

Sorry, I’m not sure which X17 connector you are referring to.

Yes, two digital audio interfaces (I2S_1 and I2S_2) are readily available on the X2 header of the Verdin Development Board.

image
image1004×648 59 KB

4

Thanks, Alex.

I was trying to work out mapping from the SOM to the Dhalia carrier board. Everything I tried left me with at least 1 of my needed pins on the X17 connector, the rest on the X19.

The pinout tool is great for getting from Signal to SOM pin.

I guess I was looking for a pinout tool that goes all the way to the carrier board… but I understand that my use case is atypical, and that tool does not exist.

Is the best way to search the carrier board PDF for the SOM PIN’s number, then see where all that pin is exposed?

5

Pretty much all module pins are exposed on the Verdin Development Board, which makes it the best choice for prototyping. Other carrier boards have certain limitations due to cost and size optimizations, so you would need to check the respective datasheet or schematic to verify which signals are available on the extension headers.

Please note that MCLK is not required for the I²S protocol itself. Some audio codecs need it, but many modern codecs can operate in slave mode using an internal PLL and require only BCLK and SYNC. Also, if you only need audio output, the I2S_x_D_IN signal can be omitted.

6

Thanks Alex… I was thinking ahead. If this is a go, I’ll need a carrier board. And using one of yours is preferable to designing my own at this stage.

I also appreciate the info on I2S. My use case is a little more complicated, so I need those 5 signals.

7

So, use the Verdin Development Board.

8

It’s too big and expensive. :frowning:

I have what I need, though. CTRL+F in the datasheet.