S32K144 CAN Rx FiFo Interrupts

[Kunal_Gettobyte]

Hi their,

I am using CAN0 in S32K144 and using Rx FiFo mechanism in that via Interrupts.

My configurations are:

1) Format A Filter table and 8 Rx Filter elements

2) CAN0 at 500kbps, Rx Fifo enabled and via interrupts

And in the main() i have written this code:

// RX FIFO Filter table structure
const Flexcan_Ip_IdTableType GB_FlexCAN_IdFilterTable[8] = {
    		{
    		.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x320
    		},
			{
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x330
			 },
			 {
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x340
			 },
			 {
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x350
			 },
			 {
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x360
			 },
			 {
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x370
			 },

			 {
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x380
			 },

			 {
			.isRemoteFrame = FALSE,
			.isExtendedFrame = FALSE,
			.id = 0x390
			 }

    };

int main(void)
{
	Flexcan_Ip_StatusType FlexCAN_Api_Status;
    /* Write your code here */
    Clock_Ip_Init(&Mcu_aClockConfigPB[0]);

#if defined (FEATURE_CLOCK_IP_HAS_SPLL_CLK)
    while ( CLOCK_IP_PLL_LOCKED != Clock_Ip_GetPllStatus() )
    {
        /* Busy wait until the System PLL is locked */
    }
    Clock_Ip_DistributePll();
#endif

    IntCtrl_Ip_EnableIrq(CAN0_ORed_0_15_MB_IRQn);
    IntCtrl_Ip_InstallHandler(CAN0_ORed_0_15_MB_IRQn, CAN0_ORED_0_15_MB_IRQHandler, NULL_PTR);

    /* Initialize all pins using the Port driver */
    Port_Init(NULL_PTR);
    /* Initilisize FlexCAN Module according to FlexCAN_Config0 data structure */
    FlexCAN_Ip_Init(INST_FLEXCAN_0, &FlexCAN_State0, &FlexCAN_Config0);

    /* Configure the RxFIFO with corresponding ID filter table acceptance format and acceptance message ID's*/
    FlexCAN_Api_Status = FlexCAN_Ip_ConfigRxFifo_Privileged(INST_FLEXCAN_0, FLEXCAN_RX_FIFO_ID_FORMAT_A, &GB_FlexCAN_IdFilterTable);

    /* Start the FlexCAN Module */
    FlexCAN_Api_Status = FlexCAN_Ip_SetStartMode(INST_FLEXCAN_0);

	/* RxFiFo in non-blocking method*/
FlexCAN_Api_Status = FlexCAN_Ip_RxFifo(INST_FLEXCAN_0, &GB_FlexCAN_Receive_Data);

    for(;;)
   {
    	/* RxFiFo in non-blocking method*/
    	FlexCAN_Api_Status = FlexCAN_Ip_RxFifo(INST_FLEXCAN_0, &GB_FlexCAN_Receive_Data);
    	TestDelay(20000000);
   }

    return 0;
}

/* END main */
/*!
** @}
*/

Now my question and issue is that under the infinite for loop, i have written  FlexCAN_Api_Status = FlexCAN_Ip_RxFifo(INST_FLEXCAN_0, &GB_FlexCAN_Receive_Data);. It works fine and my Interrupt is working fine. 

But if i remove this API from for loop and put it above for loop and in for loop its just delay like this:

/* RxFiFo in non-blocking method*/
FlexCAN_Api_Status = FlexCAN_Ip_RxFifo(INST_FLEXCAN_0, &GB_FlexCAN_Receive_Data);
    for(;;)
   {

    	TestDelay(20000000);
   }

Then my interrupt is not generated regularly. It only generates for first time and once it enters in for loop then if i send CAN data my Rx FiFo interrupt is not generated for the message ID that are configured in filter table.

So why is this happening? As if I am using interrupt it should trigger interrupt in infinite loop if any CAN received data comes in. Do we have to call FlexCAN_Ip_RxFifo() API everytime to receive data? If that is the case, isnt that wrong because if i have to call API to receive data everytime then its fundamental usecase would not happen.

Let me know if i am missing something and what should be workaround. My ask is simple that i want to receice CAN data via Rx FiFo in interrupt data if any new can data of configured message id comes, even if code is in infinite loop

[Senlent]

Hi@Kunal_Gettobyte

Please refer to this post and also you can find demo in this articles.

https://community.nxp.com/t5/S32K-Knowledge-Base/S32K1xx-FlexCAN-Mask-Setting-Demo/ta-p/1519753

[Kunal_Gettobyte]

Hi,

Thanks, problem solved.

Thanks