Questions about CAN state

[jm_shin]

Hello

When we successfully received the CAN message, we checked that 'mbs [mb_idx] .state' was set to 'FLEXCAN_MB_IDLE' in 'FLEXCAN_DRV_GetTransferStatus'.

However, there is a problem when receiving different CAN ID Messages.
'Mbs [mb_idx] .state' is set to 'FLEXCAN_MB_IDLE' regardless of the CAN ID when receiving the first CAN ID Message and receiving another CAN ID Message

To improve this, 'CAN_Init' is performed after 'CAN_Deinit', but mbs '[mb_idx] .state' is keep as 'FLEXCAN_MB_IDLE'.

ex)

while(CAN_GetTransferStatus(&can_pal1_instance, RX_BUFF_IDX) == STATUS_BUSY);

CAN_Deinit(&can_pal1_instance);
CAN_Init(&can_pal1_instance, &can_pal1_Config0);

while(CAN_GetTransferStatus(&can_pal1_instance, RX_BUFF_IDX_2) == STATUS_BUSY);

Could you please share the guide to resolve this issue

Thanks

[PetrS]

Hi,

the driver works this way.

CAN_Receive(INST_CAN_PAL1, RX_MAILBOX, &recvMsg) is used to start receiving data in RX_MAILBOX. After successful receive "recvMsg" is updated with receive data and driver's structure 'mbs [mb_idx] .state' is set to 'FLEXCAN_MB_IDLE'.

To allow another receive into RX_MAILBOX you need to call CAN_Receive(INST_CAN_PAL1, RX_MAILBOX, &recvMsg) again after while(CAN_GetTransferStatus(&can_pal1_instance, RX_BUFF_IDX) == STATUS_BUSY); passes.

BR, Petr

[jm_shin]

Dear Petr Stancik

Thank you for answer.

CAN_Receive could be called again to receive another message on RX_MAILBOX.

I would like to receive various Msg IDs.
However, in the example, only one Msg ID is set, and only the declared Msg ID is waiting for reception.
How do I receive various Msg IDs?
Do I need to set up multiple RX_MALEBOX? Or can I set various Msg IDs in 'CAN_ConfigRxBuff', 'CAN_Receives'?

Thanks

[PetrS]

Hi,

either you will prepare more MBs for individual IDs or will set mask register to accept ID range or all IDs into single MB, as was e.g. discussed here https://community.nxp.com/message/1059503

BR, Petr

[jm_shin]

Dear Petr Stancik

Could you please explain 'FLEXCAN_DRV_SetRxIndividualMask' function?

I expected to receive CAN msg of all IDs, but olny ID set in 'FLEXCAN_DRV_ConfigRxMb' wiil be received.

The test code is shown below.

=================================================

FLEXCAN_DRV_ConfigRxMb(INST_CANCOM1, RX_MAILBOX_1, &dataInfo, 0x100); //RX_MAILBOX_1 = 1UL
 FLEXCAN_DRV_SetRxIndividualMask(INST_CANCOM1,FLEXCAN_MSG_ID_STD,RX_MAILBOX_1,0xFFFFFFFFu);
 FLEXCAN_DRV_Receive(INST_CANCOM1, RX_MAILBOX_1, &recvBuff);

 for(;;)
 {
  if(FLEXCAN_DRV_GetTransferStatus(INST_CANCOM1, RX_MAILBOX_1) == STATUS_SUCCESS)
  {
   FLEXCAN_DRV_Receive(INST_CANCOM1, RX_MAILBOX_1, &recvBuff);
   count ++;
  }
 }

=================================================

Please correct me if I misunderstood your answer.

Thanks

[PetrS]

Hi,

you received single ID only as you did not clear Mask register, also be sure if individual or global masking scheme is used. See more in below post

https://community.nxp.com/message/940289?commentID=940289#comment-940289

BR, Petr