How to configure System bootloader/DFU to ignore CAN traffic

[kareled]

Hello,

customer using custom F412 based board has a problem entering STM's System bootloader/DFU for FW upgrade (done over USB) when there is an active communication done on the CAN port.

E.g. the board is part of the slave HW of the CANopen network which does have its master. At least master on the network periodically sends CANopen heartbeat messages. Our idea is that such messages on CAN bus seems to disturb system boot code as the behavior we see is that reset and enter to sysboot kind of happen but nearly immediately system boot is exited and standard user/FW is booted again.
When we disconnect CAN bus such behavior does not happen. The problem with the hardware is that it makes operation of disconnecting from the CAN somewhat difficult. Hence the question:

Is it possible to somehow (anyhow) configure system boot/DFU to ignore CAN bus?

Thanks!
Karel

[SofLit · Accepted solution]

Hello,

Not sure I catch the point.

But according to the AN2606 / Figure 39.Bootloader V9.x selection for STM32F412xx:

CAN has the priority on USB DFU:

So to prevent the CAN frame detection while entering system bootloader, you need either to change the CAN pins and select other alternate functions or disconnect the CAN from the bus.

Hope I answered your question.