DEVKIT-MPC5748G CAN1 configuration

[yuriy_serdyuk]

Hi i have problems with CAN1 configuration (CAN0 works fine).

I have this code with PC10 and PC11 pins are connected to PCAN-USB

void peri_clock_gating (void) {  /* Configure gating/enabling peripheral(CAN) clocks */
 MC_ME.RUN_PC[0].R = 0x00000000;   /* gate off clock for all RUN modes */
 MC_ME.RUN_PC[1].R = 0x000000FE;   /* config. peri clock for all RUN modes */

 MC_ME.PCTL[70].B.RUN_CFG = 0x1;   /* FlexCAN 0: select peri. cfg. RUN_PC[1] */
 MC_ME.PCTL[71].B.RUN_CFG = 0x1;   /* FlexCAN 1: select peri. cfg. RUN_PC[1] */
}


void readCanBus1(unsigned int *id, unsigned char *buf,unsigned int len,unsigned int *outLen)
{
 uint8_t j;
 uint32_t __attribute__ ((unused)) dummy;

 while (CAN_1.IFLAG1.B.BUF4TO1I != 8) {};
 *id     = CAN_1.MB[4].ID.B.ID_STD;
 *outLen = CAN_1.MB[4].CS.B.DLC;
 if (*outLen>len)
 {
  *outLen=len;
 }

 for (j=0; j<(*outLen); j++) {
  buf[j] = CAN_1.MB[4].DATA.B[j];
 }

 dummy = CAN_1.TIMER.R;
 CAN_1.IFLAG1.R = 0x00000010;
}

void writeCanBus1(unsigned int id, unsigned char *buf,unsigned int len)
{
 uint8_t i;

 CAN_1.MB[0].CS.B.IDE = 0;
 CAN_1.MB[0].ID.B.ID_STD = id;
 CAN_1.MB[0].CS.B.RTR = 0;
 CAN_1.MB[0].CS.B.DLC = len;
 for (i=0; i<len; i++) {
  CAN_1.MB[0].DATA.B[i] = buf[i];
 }
 CAN_1.MB[0].CS.B.SRR = 1;
 CAN_1.MB[0].CS.B.CODE =0xC;
}

void initCanBus1()
{
 int i;
 CAN_1.MCR.B.MDIS = 1;
 CAN_1.CTRL1.B.CLKSRC=0;
 CAN_1.MCR.B.MDIS = 0;
 while (!CAN_1.MCR.B.FRZACK) {}
 CAN_1.CTRL1.R = 0x04DB0086;
 for (i=0; i<96; i++) {
  CAN_1.MB[i].CS.B.CODE = 0;
 }

 //TX
 CAN_1.MB[0].CS.B.CODE = 8;

 //RX
 CAN_1.MB[4].CS.B.IDE = 0;
 CAN_1.MB[4].ID.B.ID_STD = 0x666;
 CAN_1.MB[4].CS.B.CODE = 4;
 CAN_1.RXMGMASK.R = 0;//0x1FFFFFFF;

 SIUL2.MSCR[42].B.SSS = 1;     /* Pad PC10: Source signal is CAN1_TX  */
 SIUL2.MSCR[42].B.OBE = 1;     /* Pad PC10: Output Buffer Enable */
 SIUL2.MSCR[42].B.SRC = 3;     /* Pad PC10: Maximum slew rate */
 SIUL2.MSCR[43].B.IBE = 1;     /* Pad PC11: Enable pad for input - CAN1_RX */
 SIUL2.IMCR[701-512].B.SSS = 3;    /* CAN1_RX: connected to pad PC11 */

 CAN_1.MCR.R = 0x0000003F;
 while (CAN_1.MCR.B.FRZACK & CAN_1.MCR.B.NOTRDY) {}
}
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Also i try send data between CAN0 and CAN1, it doesn't work. I suppose i have some problem with configuration CAN1

Could you help me?

I know CAN1 doesn't have termination resistor. I tried connected CAN0, CAN1 and PCAN-USB parallels 

Thank you

[lukaszadrapa]

Hi,

I'm just wondering how did you connected CAN 1? Did you use external CAN transceiver connected by wires? There's CAN transceiver only for CAN 0 on this board.

Regards,

Lukas

[yuriy_serdyuk]

Hi Lukas, 

What does this mean. "There's CAN transceiver only for CAN 0 on this board."

According datasheet eight FlexCAN.

I have connected PB0 - PC10 - CAN-H PCAN-USB and PB1 - PC11 - CAN-L PCAN-USB

[lukaszadrapa]

Hi,

yes, there are 8 CAN modules. But one thing is CAN module, second thing is CAN transceiver defined by ISO 11898-2.

First link and picture I found on the web:

https://can-newsletter.org/assets/files/ttmedia/raw/778ff25c6a48bbd0d67b4eee94ea11ea.pdf 

This is what you need. Only a few MCUs have CAN transceiver implemented directly on the chip (like some of our 16bit S12 devices).

There's TJA1044GT on CAN 0 as you can see in the schematic.

TJA1044 | High-speed CAN transceiver with Standby mode | NXP 

PCAN-USB also includes high speed transceiver. It's not possible to connect CAN signals without the transceiver.

Regards,

Lukas

[yuriy_serdyuk]

Hi Lukas, 

I have checked schematic my board, it's surprise for me. 

Thank you for information.