Can't use register to set 500k CAN communication failed

979409808 — Wed, 24 Jun 2020 09:33:46 GMT

FS32K118 +S32DS + 500kbps

Make bootloader, debug can download, initialization failed, no data can be received with the host computer, please check to see which parameter is wrong. thanks！！！

void FIRC_init_48MHz(void)
{
SCG->FIRCCFG=0x00000000;
SCG->FIRCCSR|=SCG_FIRCCSR_FIRCEN(0X01);//Turn on the FIRC
/*! Fast IRC is enabled and trimmed to 48 MHz in reset (default).
* Set FIRCDIV1 & FIRCDIV2 = 1: divide by 1 = 48 MHz.
* */
SCG->FIRCDIV = SCG_FIRCDIV_FIRCDIV1(1)|
SCG_FIRCDIV_FIRCDIV2(1);

}

void CAN0PORT_init(void)
{
PCC->PCCn[PCC_PORTB_INDEX] |= PCC_PCCn_CGC_MASK; /* Enable clock for PORTB */
PORTB->PCR[0]|=PORT_PCR_MUX(5); /* Port B, bit 0, ALT=5: CAN0 RX. */
PORTB->PCR[1]|=PORT_PCR_MUX(5); /* Port B, bit 1: ALT=5: CAN0 TX. */
}

void FLEXCAN0_init(void)
{
#define MSG_BUF_SIZE 4 /* Msg Buffer Size. (CAN 2.0AB: 2 hdr + 2 data= 4 words) */
uint32_t i=0;

// PCC->PCCn[PCC_FlexCAN0_INDEX] |= PCC_PCCn_CGC_MASK; /* CGC=1: enable clock to FlexCAN0 */
PCC->PCCn[PCC_FlexCAN0_INDEX] = PCC_PCCn_PR_MASK|PCC_PCCn_CGC(1); //FlexCAN0 BIU is enabled (48 MHz).
CAN0->MCR |= CAN_MCR_MDIS_MASK;         /* MDIS=1: Disable module before selecting clock */
//CAN0->CTRL1 &= ~CAN_CTRL1_CLKSRC_MASK; /* CLKSRC=0: Clock Source = SOSCDIV2    */
CAN0->CTRL1 |= CAN_CTRL1_CLKSRC_MASK;  /* CLKSRC=1: Clock Source = SYS_CLK to generate the CAN time sements (48MHz)    */
CAN0->MCR &= ~CAN_MCR_MDIS_MASK;        /* MDIS=0; Enable module config. (Sets FRZ, HALT) */

while (!((CAN0->MCR & CAN_MCR_FRZACK_MASK) >> CAN_MCR_FRZACK_SHIFT)) {}
/*!
* Good practice:
* ===================================================
* wait for FRZACK=1 on freeze mode entry/exit
*/
CAN0->CTRL1 = 0
//      #if defined(S32K11x_SERIES)
      |CAN_CTRL1_PRESDIV(5)   /* PRESDIV=4: Sclock=PEclock/(PRESDIV+1) = 48MHz/5 = 8MHz    */
//      #endif
      |CAN_CTRL1_PSEG2(4)     /* Configure for 500 KHz bit time         */
    |CAN_CTRL1_PSEG1(3)   /* Time quanta freq = 16 time quanta x 500 KHz bit time= 8MHz */
    |CAN_CTRL1_PROPSEG(7)  /* PRESDIV+1 = Fclksrc/Ftq = 8 MHz/8 MHz = 1      */
    |CAN_CTRL1_RJW(3)   /*    so PRESDIV = 0            */
    |CAN_CTRL1_SMP(1)   /* PSEG2 = Phase_Seg2 - 1 = 4 - 1 = 3        */
    |CAN_CTRL1_LPB(0);  /* PSEG1 = PSEG2 = 3            */
         /* PROPSEG= Prop_Seg - 1 = 7 - 1 = 6        */
         /* RJW: since Phase_Seg2 >=4, RJW+1=4 so RJW=3.     */
         /* SMP = 1: use 3 bits per CAN sample        */
         /* CLKSRC=0 (unchanged): Fcanclk= Fosc= 8 MHz      */
                        /*CAN_CTRL1_LPB(1):enable loopback mode for debug*/
for(i=0; i<128; i++ )
{        /* CAN0: clear 32 msg bufs x 4 words/msg buf = 128 words */
    CAN0->RAMn[i] = 0; /* Clear msg buf word */
}
for(i=0; i<16; i++ )
{                /* In FRZ mode, init CAN0 16 msg buf filters */
    CAN0->RXIMR[i] = 0xFFFFFFFF; /* Check all ID bits for incoming messages */
}
CAN0->RXMGMASK = 0x1FFFFFFF;     /* Global acceptance mask: check all ID bits */
CAN0->RAMn[ 4*MSG_BUF_SIZE + 0] = 0x04000000; /* Msg Buf 4, word 0: Enable for reception */
                                                /* EDL,BRS,ESI=0: CANFD not used     */
                                                /* CODE=4: MB set to RX inactive     */
                                                /* IDE=0: Standard ID        */
                                                /* SRR, RTR, TIME STAMP = 0: not applicable */

CAN0->RAMn[ 4*MSG_BUF_SIZE + 1] = ((uint32_t)0xa5<<18)&0X1FFC0000; /* Msg Buf 4, word 1: Standard ID = 0x511   */
                                /* PRIO = 0: CANFD not used */
CAN0->MCR = 0x0000001F;       /* Negate FlexCAN 1 halt state for 32 MBs */

while ((CAN0->MCR && CAN_MCR_FRZACK_MASK) >> CAN_MCR_FRZACK_SHIFT) {}
/* Good practice: wait for FRZACK to clear (not in freeze mode) */

while ((CAN0->MCR && CAN_MCR_NOTRDY_MASK) >> CAN_MCR_NOTRDY_SHIFT) {}
/* Good practice: wait for NOTRDY to clear (module ready) */
}

Re: Can't use register to set 500k CAN communication failed

Alexis_A — Thu, 25 Jun 2020 23:17:57 GMT

Hello Dylan,

In the following link, you can find a FlexCAN code example that could help you in your application. Also, in the SDK you can find a bootloader example that you could check.

Best Regards,

Alexis Andalon

topic Can't use register to set 500k CAN communication failed in S32K

Can't use register to set 500k CAN communication failed

Re: Can't use register to set 500k CAN communication failed