topic Re: FlexCAN RX FIFO with Extended 29-Bit CAN IDs not Working in S32K

FlexCAN RX FIFO with Extended 29-Bit CAN IDs not Working

gbrowne — Wed, 21 Mar 2018 16:05:52 GMT

Hello.

I have run tests on the S32K144 with sending and receiving both standard (11-bit) and extended (29-bit) ID CAN frames. What I have found is that I cannot receive extended ID frames when I use the RX FIFO, but I can receive standard ID frames.

Also, I can receive both standard and extended ID frames if I receive into a specific message buffer (i.e. the non-FIFO method).

So, is there something special to setting the RX FIFO to receive extended ID frames? Is there working sample code for receiving extended ID frames with the RX FIFO?

Here is a general overview of my routines:

RX FIFO Routine (which only works for standard 11-bit ID frames):

FLEXCAN_DRV_Init(...)
FLEXCAN_DRV_SetRxMaskType(...)
FLEXCAN_DRV_SetRxFifoGlobalMask(...)
FLEXCAN_DRV_ConfigRxFifo(...)
FLEXCAN_DRV_ConfigTxMb(...)
FLEXCAN_DRV_Send(...)
FLEXCAN_DRV_RxFifoBlocking(...)

Specific Message Buffer Routine (which works for both standard 11-bit and extended 29-bit ID frames):

FLEXCAN_DRV_Init(...)
FLEXCAN_DRV_SetRxMaskType(...)
FLEXCAN_DRV_SetRxMbGlobalMask(...)
FLEXCAN_DRV_ConfigRxMb(...)
FLEXCAN_DRV_ConfigTxMb(...)
FLEXCAN_DRV_Send(...)
FLEXCAN_DRV_ReceiveBlocking(...)

Any insights would be much appreciated.

Thanks!

-Greg

Re: FlexCAN RX FIFO with Extended 29-Bit CAN IDs not Working

AnaAldescu — Thu, 22 Mar 2018 08:49:31 GMT

Hello Greg,

There is a known bug related to the Rx FIFO filters. If you're using other filter format than format A, extended ID's won't match the filter. This bug will be fixed in the next S32 SDK release.

If you're using format A for the ID filters, please make sure you configure the ID filter table with extended IDs:

flexcan_id_table_t filterTable[8U];

filterTable[0].id = 0x1FFFFFFF;
filterTable[0].isExtendedFrame = true;

FLEXCAN_DRV_ConfigRxFifo(INST_CANCOM1, FLEXCAN_RX_FIFO_ID_FORMAT_A, filterTable);

Please let me know if the problem is not solved.

Best regards,

Ana

Re: FlexCAN RX FIFO with Extended 29-Bit CAN IDs not Working

gbrowne — Thu, 22 Mar 2018 11:32:44 GMT

Ah, much appreciated Ana!

I was missing that extra isExtendedFrame flag in the filter table.

Thanks!

-Greg