FDCAN H5 Memory Access Failure

[dnugent]

I'm experiencing FDCAN Memory Access Failures on the STM32H503KBUX during CAN Rx. 

I am also experiencing intermittent CAN Rx message drops (every 1 in a 200), and I believe the two are related since no others errors are firing. I know the drops are happening on the STM32 because I can see the messages on the bus with my CAN debugger and there are no error frames. 

I'm struggling to understand why this Memory access error is happening and how to proceed with solving it. The only info I can find is in rm0492. However, it doesnt really say what might cause these events to happen. 

Other relevant info:

- Using internal clock
- Freertos

- Using to `HAL_FDCAN_RxFifo0Callback` to read from FIFO

- Config

 hfdcan1.Instance = FDCAN1;
 hfdcan1.Init.ClockDivider = FDCAN_CLOCK_DIV1;
 hfdcan1.Init.FrameFormat = FDCAN_FRAME_CLASSIC;
 hfdcan1.Init.Mode = FDCAN_MODE_NORMAL;
 hfdcan1.Init.AutoRetransmission = ENABLE;
 hfdcan1.Init.TransmitPause = ENABLE;
 hfdcan1.Init.ProtocolException = ENABLE;
 hfdcan1.Init.NominalPrescaler = 16;
 hfdcan1.Init.NominalSyncJumpWidth = 128;
 hfdcan1.Init.NominalTimeSeg1 = 13;
 hfdcan1.Init.NominalTimeSeg2 = 2;
 hfdcan1.Init.DataPrescaler = 1;
 hfdcan1.Init.DataSyncJumpWidth = 16;
 hfdcan1.Init.DataTimeSeg1 = 1;
 hfdcan1.Init.DataTimeSeg2 = 1;
 hfdcan1.Init.StdFiltersNbr = 1;
 hfdcan1.Init.ExtFiltersNbr = 1;
 hfdcan1.Init.TxFifoQueueMode = FDCAN_TX_FIFO_OPERATION;

- Using a filter

void can_setupFilter(void) {
	FDCAN_FilterTypeDef sFilterConfig;
	sFilterConfig.IdType = FDCAN_EXTENDED_ID;
	sFilterConfig.FilterIndex = 0;
	sFilterConfig.FilterType = FDCAN_FILTER_RANGE;
	sFilterConfig.FilterConfig = FDCAN_FILTER_TO_RXFIFO0;
	sFilterConfig.FilterID1 = 0;
	sFilterConfig.FilterID2 = 0x1FFFFFFF;

	if (HAL_FDCAN_ConfigFilter(canPtr, &sFilterConfig) != HAL_OK) {
		Error_Handler();
	}
}

Happy to share additional details upon request.

 

Any ideas on how to debug or fix this issue?

Best,

Daniel

 

 

[mƎALLEm]

Hello,

---

@dnugent wrote:

- Using internal clock

---

1- Not recommended. Please use a crystal or other precise source of clock.

 

---

@dnugent wrote:

- Freertos

---

2- Better to do the test without RTOS.

3- Try to increase the value of the extended filter number:

 hfdcan1.Init.ExtFiltersNbr

 

[dnugent]

Thank you for your response!

Increasing filter number did not help.

 

I was able to subdue the MRAF error by creating a new barebone project, however, I still have packet drops. 

 

The new bare bones project just has FDCAN enabled and no FreeRTOS. Im sending a fixed number of messages from a working STM32 and counting them with my CAN debugger and the H5. This new project still has a drop rate of 1 in 200.

 

I've ordered a dev board to see if the external oscillator helps. I will report back with my findings.

 

Thanks,

Daniel

[dnugent]

I misspoke, the MRAF error is still firing with the barebones project.