system boot loader FDCAN

[MMagl]

Rev V system boot loader FDCAN

STM introduces boot via FDCAN1 with chip revision V.

The system boot loader version is

changed form V13.3 to V9.0.

I’ve tried to figure out how does it work. Here are my findings

-     AN2606 rev 38 is updated. It describes at high level the STM32H7 system boot loader.

-     AN3154 is not up to date or the purpose is to describe only the legacy STM32 devices. Limited scope to CAN not FDCAN

https://www.st.com/content/ccc/resource/technical/document/application_note/56/94/0c/7d/63/f6/4d/96/CD00264321.pdf/files/CD00264321.pdf/jcr:content/translations/en.CD00264321.pdf

-     Wiki page is not up to date. Many thinks are not correct there. STM32H7 is completely missing. It also says that “The FDCAN is not used at boot time.�?

https://wiki.st.com/stm32mpu/wiki/FDCAN_internal_peripheral

My questions are

1.     Is there any document that describes the system boot loader via FDCAN? I’m looking for something similar to AN3154.

2.     What type of FDCAN commands are supported?

3.     How can I activate boot via CAN, do I need to send CAN_ID 0x79 message?

4.     What is the boot loader code sequence? E.g. frame detection, FD speed and crystal oscillator adjustment.

5.     What are the hardware requirements to boot via FDCAN? E.g. Do I need fixed crystal frequency 8MHz,25MHz, 14.7456MHz?

[MMagl]

I would like to shere the solution that I found out.

I'm going to use OpenBLT. The reasons of my choice are

1. STM32 system boot loader seems to be closed project or at least I did not find the source. STM did not answer me either
2. STM boot loader seems to have problems with CAN - looked at errata
3. STM FDCAN boot loader seems to appear for the first time in STMH7 rev. V chips -- not not documented and unknown bugs.

Open BLT is

1. Open source
2. Proven to work solution
3. Good community and company support -
4. Flexible licences - Open source of commercial
5. Modular solution - extend or shrink according to your needs.

links

https://github.com/feaser/openblt/tree/master/Target

https://www.feaser.com/en/addons.php

[IgorRUser15759641494006331970]

I've just started investigation of CAN bootloader and I found AN5405:

https://www.st.com/content/ccc/resource/technical/document/application_note/group1/fc/44/eb/f7/3f/4a/45/60/DM00660346/files/DM00660346.pdf/jcr:content/translations/en.DM00660346.pdf

Regards

[MMagl]

Thanks,

Stm promised to give documentation Q3 2019. I see that AN2606 is updated too.

I think that STM will perform some iterations in area of FDCAN boot loader. For example. STM32 h7 FD CAN is hard coded to pins PH13 and PH14. Both pins are only available on BGA package.

I've attached the updated AN2606

https://www.st.com/content/ccc/resource/technical/document/application_note/b9/9b/16/3a/12/1e/40/0c/CD00167594.pdf/files/CD00167594.pdf/jcr:content/translations/en.CD00167594.pdf

Best Regards,

Mirtcho Maglijanov