ST Webinar on the STM32MP1 MPU in the DHSOM product family

Date : 24. April 2020

On this page we want to answer the most frequently asked questions from the ST webinar on 9th of April on the topic 
"STM32MP1 MPU and DH electronics' SOM product family".

1. Are customer-specific variants of the modules available?
   Yes. You can configure your specific DHCOR or DHCOM variant and choose CPU type, DDR size, availability of a second ethernet controller and many more features according to your needs. You will find all the options on our datasheets.
    
2. Is the long-term availability limited to 2x 512 MB DDR3L Memory?
   No. The long-term availability is not limited to 1 GB DDR3L memory.
    
3. What are the differences between Mainline and OpenSTLinux Yocto?
   OpenSTLinux uses the ST layers as dependency. The Yocto layer for our mainline Linux uses only Poky as reference. In that case it's much easier to update the mainline based Yocto version to a newer release, because we only use Poky as feature set. On the other hand, OpenSTLinux will bring additional features and tools with it.
    
4. Uses the Mainline Yocto implementation Poky?
   Yes, the mainline Yocto implementation is based on Poky. Some words to Poky: It contains the OpenEmbedded Build System (BitBake and OpenEmbedded Core) as well as a set of metadata to get you started building your own distro. This means Poky is a reference distribution as starting point for your own project.
    
5. What is the minimum order quantity for the DHSOM modules?
   DHCOM: 1 pc
   DHCOR: 360 pcs due to tape and reel packaging (samples available)
    
6. What are the dimensions of the modules?
   Solderable DHCOR: 29.0 x 29.0 mm
   Pluggable DHCOM: 36.7 x 67.6 mm
    
7. Are both modules supported by the official Linux Mainline Kernel?
   Yes. Most of the DHCOM STM32MP1 parts are already up streamed today and we are currently working on the upstream of the DHROR STM32MP1 by upstreaming the Avenger96 board at first. Next to the official Mainline Kernel repository, we are backporting the Mainline patches to the current LTS Kernel version. This version (5.4) will be available on our GitHub repositories and represent our official release version.
    
8. Do the software images for the modules provide a desktop system like Ubuntu?
   Yes and no. OpenSTLinux is based on Weston and provides the typical Weston desktop. Our Mainline based versions do not directly provide a desktop, but you can adjust the Yocto layer and add a desktop to your specific image. By default, the standard Mainline images contain Qt 5 and also the Qt 5 minimal web browser which allows you to directly run HTML based applications on the system.
    
9. Can I get the modules with preprogrammed software?
   Yes. All modules will be delivered with a preprogrammed default version of U-Boot in the SPI flash which means that U-Boot will start up after you plug in the power supply for the first time. Afterwards you can use the update mechanism to program your specific image in U-Boot. Additionally, we can install your customer specific image on the modules directly in our test bench and deliver them ready for use.
    
10. Do you support secure boot?
    Yes. ST directly supports secure boot via OpenSTLinux and also our Mainline based Linux does also support secure boot.
     
11. Do you offer a cooling solution for the DHCOR similar to 5-Cent Cooling for DHCOM?
    We advise to mount the module on the bottom side of the mainboard (like on the reference design Avenger96). Then you can use the same gap pad as for the 5-Cent cooling solution to connect the STM32MP1 SoC to a housing or mounting plate. This depends always a little bit on the application, but typically you have connectors and higher components on the top side of the mainboard, therefore it makes sense to mount the DHCOR on the bottom side, because you then can mount the mainboard with a small gap from the bottom side to the housing in your device. And this gap can be closed with the gap pad.
     
12. Why is the heat of the MP1 in the example only reduced by 23 °C with the 5-Cent Cooling solution?
    As ST uses a plastic housing the thermal resistance is higher than with a metal housing. For the MP1 the plastic housing seems to be adequate since the CPU has only approx. 1.5 W maximum power consumption.
     
13. Why do you provide a Debian based system next to Yocto with your modules?
    Yocto is used you build your own distribution which means you are self-responsible for the maintenance. With Debian you are using a real distribution. This means Debian cares about bug fixes and updates over the next years. So with Debian you can reduce the maintenance efforts what really makes sense for some projects.
     
14. Why don’t you provide any prices on your website?
    As customer of DH electronics you profit from a high level of flexibility and are able to customize your module according to your needs. This allows you to choose between many different options which are all shown in our datasheets. At the same time, this leads to many different types of modules and therefore it makes no sense to provide prices for all of them on our website. Please have a look at the second page of our datasheets and choose the options you need. Send us your individual ordering code afterwards and we can send you our prices based on that concrete information.
     
15. What does long-term availability mean in context with the STM32P1?
    Our modules are available as long as the STM32MP1 is available. Today this means that our module will be available at least until the year of 2029.
     
16. Do the DHCOMs fit industry standard interfaces such as SMARC2?
    No. The DHCOM is based on our own DH standard with a SODIMM-200 socket. From our point of view the problem with SMARC is that it must fit to X86 and ARM. Therefore, the modules and the connector are much more expensive compared to our DHCOMs. In addition too, SMARC2 is a much larger design than DHCOM modules.
     
17. Can you explain what is meant by HW Crypto?
    The STM32MP1 contains a dedicated cryptography and hashing block which provides cryptography features like AES and TDES and hashing functions like SHA-256 as well has true random number generation and CRC calculation. As all those functions are accelerated by the Crypto hardware which unloads the CPU and is very fast.
     
18. Is the DHCOM also available without WiFi/Bluetooth?
    Yes. As customer of DH electronics you profit from a high level of flexibility and are able to customize your module according to your needs. This allows you to choose between many different options which are all shown in our datasheets. Please choose your preferred options and send us the so created ordering code.
     
19. Which voltages can be provided by the STM32MP1?
    IO, USB, SD Card voltage, … Please have a look at the Avenger96 design and at the DHCOR STM32MP1 user manual: https://www.dh-electronics.com/fileadmin/files/product-details/usm_dhcor-stm32mp1_r05_2019-12-12.pdf
     
20. Do you offer Altium libraries for board design?
    No, only for Orcad and Allegro. But you should be able to import the design. The Allegro Files can be downloaded here: https://www.dropbox.com/s/yjx9l0qj9ja0de8/DHCOR-STM32MP1-Design-Symbols_2019-10-16.zip?dl=0
     
21. How do the A7 and M4 core communicate with each other?
    The interprocessor communications channel (IPCC) uses standard Linux rproc and RPMsg.
     
22. Are you supporting SGET open-standard-module standard?
    No. We don't support the SGET open-standard-module because on our solderable DHCOR we want to provide the full feature-set of the SoC without making a compromise due to standardization. However, there are also some advantages of standardized System on Modules and this is why we are still committed to both, our DHCOR for full feature-set and our DHCOM-Modules with our DHCOM standard.
     
23. Do you provide a CODESYS runtime SW implementation for the DHSOMs?
    No. We don't support CODESYS runtime SW. We recommend using 4DIAC which is IEC 61499 conform, free of charge and open source.
     
24. Are the CAN signals available at the Avenger96 board?
    Yes. The CAN signals are available on some GPIOs of the low speed expansion connector. Please note that with the standard images the pins are configured as GPIOs in Linux and you must therefore add the CAN configuration to the device tree first.
    Please have a look at the connector X6, you find the schematics here: https://www.dropbox.com/s/u8nihe1xd6ysk3v/SCH_588-200-HS00008-public_R07_2019-08-01.pdf?dl=0
     
25. What standard tests are part of your pre-certification tests?
    We are always testing regarding to European standards. For example, we are testing the radiated emission due to EN 55032:2016 class B requirements. Next to radiated emission we are also doing burst EMC tests according to EN 61000-6-2. In addition too, our WiFi/Bluetooth modules are pre-certified according to European RED. We can also do FCC testing too.
     
26. Where can the modules (and other products of DH electronics) be purchased?
    You can order our DHSOMs directly from us or via our partners Arrow or Alcom Electronics.
     
27. What is the difference between DSP and M4?
    We will gladly answer detailed questions on that topic on request.
     
28. Is the web browser based on Qt?
    Yes, on the demo application all the motor parameters from the Cortex M4 Core are being showed on an Qt based WebBrowser which is running on the Cortex A7 Cores on the STM32MP1. Qt WebEngine provides an integrated WebBrowser component based on Chromium. This WebBrowser is used in the motor demo.
     
29. What communication mechanisms between the A7 and M4 core are available?
    Apart from shared memory you can also make use of the inter processor communications channel (IPCC) which is rproc and RPMsg.
     
30. Have DHCOM and/or DHCOR been used in applications requiring Ex(Atex) or SIL approvals?
    We do not know in which applications our customers are using DHSOMs, so we can't tell you if our DHSOMs have been used in such applications already. 
     
31. What are the debug features of the STM32MP1?
    Please have a look at https://wiki.st.com/stm32mpu/wiki/Trace_and_debug_tools.
     
32. Do you have experience with Qt for MCU on the STM32MP1 (without Linux)?
    No. Not yet. You can find more info under https://www.mikrocontroller.net/topic/479820
     
33. Can you suggest an eMMC that you route BGA pins in the tricky way from?
    The housing and pinout of an eMMC is standardized by the JEDEC and therefore it works with every standardized eMMC.
     
34. Do you support the integration of communication stacks?
    We will gladly answer detailed questions on that topic on request.
     
35. About the pre-certification which standards are pre-tested? 62304 and 60601?
    Regarding pre-certification standards see answer to question 25. Regarding tests according to medical standards we offer this on project base.
     
36. Am I still able to debug the M4 via SWD, while M7 runs its OS?  Is SWD wired?
    Yes. The SWD Interface is shared with the JTAG pins and the pins are available on DHCOM and DHCOR as well on the Avenger96 board.
     
37. What Linux Kernel version do you recommend to get hardware accelerated OpenGL?
    At the moment we support 4.19 LTS Kernel with OpenSTLinux and 5.4 LTS Kernel with our Mainline based Linux. Both versions support OpenGL. As we started our STM32MP1 project with the newest available LTS Kernel versions, we don’t support older Linux Kernel versions.
     
38. What operating systems and languages as supported?
    You can use the OpenSTLinux or our Mainline based Linux. We don't support Mbed OS by ourselfs at the moment. The GPIOs can be accessed like on any other Linux device. For instance you can make use of "gpiod".
     
39. Where can I find documentation for the Avenger96 board?
    The documentation can be found at our website under the product page or support tab (https://wiki.dh-electronics.com/index.php/Avenger96). When it comes to the ordering, you'll find the Avenger96 board at https://www.arrow.com/.
     
40. Does the DHCOR have all peripherals available on the pinout?
    Yes. Other than the DHCOM, the DHCOR has an individual pinout and therefore you can make use of all its features.
     
41. Are the modules CE and RTTE certificated and can I directly use them in my products?
    No. We are doing CE pre-certifications with our DHSOMs. A real end certification with a SOM is not possible, because the results always depend on the application software, mainboard, used interfaces, housing and so on. As a result, you always have to certify your end product.
     
42. Is the STM32MP1 suitable for low power or battery powered (standalone) systems?
    Yes. The STM32MP1 supports low power modes, therefore the device is suitable for battery powered standalone systems. We are using the STPMIC on our modules. This part is mandatory to support full featured low power modes.
    Please also have a look at the application note from ST: https://www.st.com/resource/en/application_note/dm00449434.pdf
     
43. Will future SOMs with more powerful processors fit to the actual architecture, so that in case for an upgrade you just have to change the SOM?
    Yes. All our DHCOM modules are sharing the same pinning and therefore you can upgrade to a more powerful DHCOM system in the future without the need of a huge redesign what is one of the biggest advantages of our modular DHCOM system.
     
44. According to the ST datasheet, the STM32MP1 has a 1 GB Ethernet interface but on the DHSOM you provide 2 x 100 Mbit. Is a Gigabit connectivity possible (single interface)?
    Yes. You can make use of the Gigabit port by choosing a different variant of our DHCOM module, but in that case you have to place an dedicated Ethernet-Phy on the baseboard.
     
45. Do you provide open source schematics for DHSOM modules and carrier boards?
    Yes and no. The schematic for the SOM itself is not open source, but in return the schematic of the carrier board is open source. You can find all the information here: https://wiki.dh-electronics.com/index.php/Avenger96
     
46. Why don't you use the STM32 RTC instead of the externally mounted RTC?
    The external RTC has several advantages compared to the internal one. The first one is its accuracy of +/- 3ppm during the whole temperature range of -40 to +85 °C. In addition to, it also requires less power than the internal one and therefore you can maximize your battery life. But if such features are not needed, you can also order the SOM without the external RTC of course, this is only an option that you might choose.
     
47. Will future DHCOR modules with more powerful processors be pin compatible with current modules?
    Each DHCOR module based on a different SoC platform has an individual pin out and therefore you can make use of all its SoC features. The DHCOR STM32MP1 will also support the new 800 MHz variant which is pin compatible.
     
48. Do you have representatives and/or distributors in the US?
    Yes. We are an Arrow Global Partner and therefore you can order our SOMs in the US by contacting your local Arrow Electronics Team.
     
49. Do you support buildroot for your SOCs? If not, do you have plans for it?
    No. Currently we are supporting Yocto and ELBE for building a Debian based system and do not plan to support buildroot in the near future.
     
50. Can you tell us more about Qt sample and the way of application?
    At the moment we are working on a Mainline based Linux version for the Avenger96 board with DHCOR STM32MP1 which will probably be released in the mid of May. This version will contain Qt 5.13 by default and OpenGL support. The same applies to DHCOM STM32MP1 version where we will have the first samples availably earliest in July 2020.
     
51. Does the SOM module have automotive grade?
    Our SOMs are designed for the industrial use. On request we also support automotive grade.
     
52. What is the Safety Integrity Level (SIL) of the STM32MP1?
    ST will deliver the X-CUBE-STL package for STM32MP1 in Q4/2020 covering SIL2 and SIL3. You can find more information under https://www.st.com/en/embedded-software/x-cube-stl.html

If you have any further questions, please do not hesitate to contact our Digital Heroes Team at any time!