CAN RX FIFO CONFIGURATION

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CAN RX FIFO CONFIGURATION

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AergoXenn
Contributor II

Hi!

I've been having some trouble getting the CAN (can0) RxFIFO working.

Since I am not using the SDK (too much CPU load for my application) I intended to use DMA transactions to unload the CPU. I wanted to test that the FIFO worked before configuring the DMA, but I can't get any messages with FIFO enabled.

Here is the CAN0 Init code, 

void CAN_vInit(CAN_Type* pstCan)
{
  CAN_tstCfg tstCfg;
  tstCfg = CAN_CONFIG;
 
  /* Disable Module */
  pstCan->MCR |= CAN_MCR_MDIS_MASK;
 
  /* Clear Clock Source  Field*/
  pstCan->CTRL1 &= ~CAN_CTRL1_CLKSRC_MASK;
 
  /* Clear Module Disable Flag */
  pstCan->MCR &= ~CAN_MCR_MDIS_MASK;
 
  /* Wait for Freeze and Halt Assert Flags */
  while (!((pstCan->MCR & CAN_MCR_FRZACK_MASK) >> CAN_MCR_FRZACK_SHIFT));

  /* Configure CAN Clocks  */
  pstCan->CTRL1 = CAN_CTRL1_CLKSRC(tstCfg.u8ClkSrc)
                | CAN_CTRL1_PRESDIV(tstCfg.u8Presdiv)
                | CAN_CTRL1_PROPSEG(tstCfg.u8Propseg)
                | CAN_CTRL1_PSEG1(tstCfg.u8PhaseSeg1)
                | CAN_CTRL1_PSEG2(tstCfg.u8PhaseSeg2)
                | CAN_CTRL1_RJW(tstCfg.u8ResyncWidth)
                | CAN_CTRL1_SMP(tstCfg.u8SmpPoints);

  /* Configure Acceptance Masks */
  pstCan->RXMGMASK = 0x1FFFFFFF;
  for (uint8 i = 0; i < 16; i++)
  {
    pstCan->RXIMR[i] = 0x1FFFFFFF;
  }
  pstCan->RXFGMASK = 0x1FFFFFFF;

  /* Enable Module */
  pstCan->MCR = CAN_MCR_SRXDIS(STD_ENABLE)
              | CAN_MCR_RFEN(STD_ENABLE);
              //| CAN_MCR_IRMQ(STD_ENABLE)
              //| CAN_MCR_LPRIOEN(STD_ENABLE);
 
  /* Wait for FRZACK Deassert */
  while ((pstCan->MCR & CAN_MCR_FRZACK_MASK) >> CAN_MCR_FRZACK_SHIFT);
 
  /* Wait for NOTRDY Deassert */
  while ((pstCan->MCR & CAN_MCR_NOTRDY_MASK) >> CAN_MCR_NOTRDY_SHIFT);
}

 

In the previous code the parameter is CAN0, so that pstCan->X is CAN0->X. 

Aside from this, I am setting the CAN0->RAMn[24] (address 0xE0 in FIFO filter table) as the desired ID for reception. Such that, 

CAN0->RAMn[24] = CONTROL_ID; 

When I send this ID, nothing changes, and there is no reception. IFLAGS1 doesn't change and IDHIT doesn't either. 

Is there anything I am missing? 

Please help.

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VaneB
NXP TechSupport
NXP TechSupport

Hi @AergoXenn 

Could you tell me which MCU you are using?

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AergoXenn
Contributor II

Sure, I am working on S32K142 on a custom developed board.

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812 Views
VaneB
NXP TechSupport
NXP TechSupport

Hi @AergoXenn 

I suggest you look at the CAN 2.0 and CAN FD examples in the S32K1xx Series Cookbook. These may be useful to you.

 

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