STM32 CanBus cannot get out of interrupt handler

[mehmet karakaya (Gast)]

hello dear forum,

I try to make CANBUS of STM32F103RC work
I managed to make CANBUS send message in loopback mode
however when I turn on receive interrupt
the processor hangs at first message and watchdog resets the micro
---------------------------------------------
 CAN_ITConfig(CAN1, CAN_IT_FMP0, ENABLE);
---------------------------------------------
I suspect the code enters the interrupt handler and cannot leave it
I want to ask how do I fill following lines to reset interupt flag and 
pending bit
---------------------------------------------
void USB_LP_CAN1_RX0_IRQHandler(void)
{
CAN_ClearFlag(CAN1, ??????????);
CAN_ClearITPendingBit(CAN1,??????????);

  CanRxMsg RxMessage;

  CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);
---------------------------------------------
thank you

[Lars F. (flemmy)]

Hey mehmet,

You use neither CAN_ClearFlag nor CAN_ClearITPendingBit. According to 
the reference manual (p. 683) CAN_IT_FMP0 is set and reset by hardware. 
As soon as you call CAN_Receive one message from the RX FIFO is read. 
The interrupt won't be called again, as soon as the FIFO message count 
has reached 0.

Greetings