S32KのトピックRe: S32K396 Transmit and receive multiple CAN messages (polling)

S32K396 Transmit and receive multiple CAN messages (polling)

ashwinibalkwade — Fri, 06 Sep 2024 09:08:10 GMT

I am trying to send and process or perform another CANTx/Tx on received CAN message.

Also, how can I do same with Interrupts?

Re: S32K396 Transmit and receive multiple CAN messages (polling)

PetrS — Fri, 06 Sep 2024 19:03:31 GMT

Hi,

you can refer to below example which shows multiple MBs usage with interrupt/callbacks too.
https://community.nxp.com/t5/S32K-Knowledge-Base/Example-S32K344-FlexCAN-Ip-TX-RX-EnhanceRXFIFO-test-S32DS3-4/ta-p/1536225
It is for S32K344, but it is similar.

BR, Petr

Re: S32K396 Transmit and receive multiple CAN messages (polling)

ashwinibalkwade — Thu, 12 Sep 2024 10:58:39 GMT

Hi @PetrS ,

Can we transmit or receive multiple messages at same time, do not want to send or receive messages for that blocking period only?

Re: S32K396 Transmit and receive multiple CAN messages (polling)

PetrS — Fri, 13 Sep 2024 11:27:53 GMT

Hi,

did not get a point much.
On the bus there is always just single message at the time, the one sent from a node which won bus arbitration. If node/MCU is receiving this message, it will be stored in MB/RXFIFO if MB/RXFIFO was configured to receive this message. Meanwhile a node can have prepared other MBs for message transmissions and those will be transmitted once selected by internal arbitration process and after first opportunity window on the bus.

BR, Petr

Re: S32K396 Transmit and receive multiple CAN messages (polling)

ashwinibalkwade — Thu, 19 Sep 2024 07:23:55 GMT

Hi @PetrS ,

I have successfully transmitted multiple messages on CAN bus.

I am still stuck in situation for receiving CAN messages. Please see the attached screenshots, Even if I am not sending any message still "RStatus" is "FLEXCAN_STATUS_SUCCESS", and when I am sending message from PCAN then also the "RStatus" is "FLEXCAN_STATUS_SUCCESS".

The msgID shows some garbage value.

Re: S32K396 Transmit and receive multiple CAN messages (polling)

PetrS — Thu, 19 Sep 2024 11:54:11 GMT

Hi,

if want to use polling mode then have below code for each reception. This would be
- start receiving, i.e. call FlexCAN_Ip_Receive
- check status using FlexCAN_Ip_GetTransferStatus and call FlexCAN_Ip_MainFunctionRead repeatedly to process received message in given MB.

FlexCAN_Ip_Receive(INST_FLEXCAN_0, RX_MB_IDX, &rxData, TRUE);
while(FlexCAN_Ip_GetTransferStatus(INST_FLEXCAN_0, RX_MB_IDX) !=FLEXCAN_STATUS_SUCCESS)
{ FlexCAN_Ip_MainFunctionRead(INST_FLEXCAN_0, RX_MB_IDX); }
...process received data in user buffer here

BR, Petr

Re: S32K396 Transmit and receive multiple CAN messages (polling)

ashwinibalkwade — Thu, 19 Sep 2024 12:40:10 GMT

Hi @PetrS ,

I tried this but FlexCAN_Ip_GetTransferStatus(INST_VS_0_FLEXCAN_0, RX_MB_IDX) returns "FLEXCAN_STATUS_SUCCESS" every time.

When I debugged the code I found that the below base->IFLAG1 is setting to 0 and hence causing the skipping of while loop.

Can you please help me to know from where is this getting set to 0, I tried debugging but didn't find the exact loophole?

Re: S32K396 Transmit and receive multiple CAN messages (polling)

PetrS — Mon, 23 Sep 2024 09:30:07 GMT

Hi,

share simplified project you are using now, to check how driver's function are used.

BR, Petr