Which pins are available for CANFD2 on STM32H747I-DISCO board ?

[DTran]

Hi Community,

I am using STM32H747I-DISCO board, I'd like to use 2 FDCAN but I can only find PA11 and PA12 on STMod+ connector for FDCAN1, seem like all of the FDCAN2 pins are not available but I'm not sure.

Could you please help to find out ?

By the way, I don't know what is the different between CANFDx_RXFD_MODE, CANFDx_TXFD_MODE and CANFDx_RX, CANFDx_TX ?

[Tesla DeLorean]

The pins on these boards tend to be heavily utilized, if the ones you need are committed to other functions then you're going to need to get a board that escapes the pins you need more cleanly.

[DTran]

So does anyone know what is the different between CANFDx_RXFD_MODE, CANFDx_TXFD_MODE and CANFDx_RX, CANFDx_TX ?

Can I use those pins for CANFD ?

[mkrug]

I'm almost sure that the xx_MODE pins are the ones that support CANFD. The others support only CAN.

Btw. did you get it to work with the STMod+ connector. I tried the same without success so far. I already set correct the soldering bridges SB.

Additionally I think even the latest CubeMX for the H747 is buggy for the FDCAN functionality. For a few pins (e.g. PD4/5) the setting pin mux for CANFD is not available. Also if you switch in CubeMX between 'Classic Master' and 'CANFD' it doesn't update the GPIO mux. Finally if you select 'Not Generate Function Call' in 'Project Manager->Advanced Settings' it doesn't realize the the ioc file has been changed - however if you generate code it behaves accordingly to you setting.

[mkrug]

In the meantime I'm not longer convinced that you can use the RXFD-/TXFD_MODE pins for regulare CAN Bus message transmission. I found somewhere a note that let me think that these pins are more related to a sort of control pin in case you are using the CANFD. However, I'm not sure.

I'm still suffering with this and therefore I sent an official request to the ST support. In case I will receive an answer I will post it here as well.