CubeMX CANFD problems with stm32H747

[mkrug]

Dear all,

the more I dig into the CANFD programming the more question marks I have concerning the CubeMX functionality.

For instance you can select CANFD1 and CubeMX is proposing to use the pin PH14. However, according to DS12931 Rev 1 this pin is very likely just able to work in CAN mode but not in CANFD. On the other side quite a few pins are missing in the pinout view that should be able to offer CANFD functionality according to the above mentioned document but the tool is not offering to configure them accordingly.

So if ST support is reading that message I would be really interested if I'm overlooking something or if CubeMX has its problems in the described way. Certainly in the latter case I would be interested when a new revision is expected.

Best Regards

Markus

[Khouloud ZEMMELI]

​Hello @Community member​ ,

Could you please give me more details about your request?

"according to DS12931 Rev 1 this pin is very likely just able to work in CAN mode but not in CANFD. " : please see attached picture , PH14 (according to DS12931 Rev 1) able to work in FDCAN1_RX mode.

"a few pins are missing in the pinout view that should be able to offer CANFD functionality " : could you please give me which pins are you talking about?

Thanks,

Khouloud.

[Khouloud ZEMMELI]

@Community member​ 

+ ​DS12931 Rev 1  is DS for STM32H757xI and not stm32H747.

Best Regards,

Khouloud

[mkrug]

Dear Kholoud,

Thanks for your reply. I'm working with the STM32H747-DISCO board. This board is populated by a STM32H747XIH6U device. So in my understanding the DS12931 Rev 1 is the correct document for this.

In the pinout view of the STM32CubeIDE the functionality 'FDCANx_TX/RX_MODE', that is listed in the DS12931 Rev 1, is not selectable (for instance PD4/5). However, the problem is a little bit more severe because even in the reference manual RM0399 there is no description about the actual functionality of these pins. From some other posts I got the impression that you can monitor the FDCANx_TX/RX activity. But again, there is no information if this is a standard high/low signal while a message frame is send/receive or is it the bit toggling during the message or even something completely different.

Even more, if I have a look in the UM2411 Rev 3 of the above mentioned DISCO board on page 59 a table is given. This table shows alternative settings for the STMod+ connector. There is an entry for pin PD4/5 that is named CAN1_TXFD and CAN1_RXFD. So again a different naming for (maybe) the same thing.

Finally, if you select FD in the STM32CubeIDE for 'Mode' there is a typo. It says 'FD Mode without BitRate Switshing'. Certainly a small thing but it makes me wonder how much more things are under the hood concerning the FDCAN functionality of this device.

Best Regards

Markus

[Khouloud ZEMMELI]

​hello @Community member​ , Thank you for the clarification, so 2 points are mentioned :

1-the different names in references for the same thing

2-the Alternate functions for PD4 and PD5 which are not the same with CubeMX

they will be internally analysed.

Thanks for your feedback.

Best Regards,

Khouloud.