TXBRP is in Pending state

[bwp530]

After ‘M_CAN_1.TXBAR.R = 0x1;’， the M_CAN_1.TXBRP.R value is always 1, and M_CAN_1 send nothing.

I transplant the code Example MPC5777M MCAN simple TX/RX GHS614 on S32ds, I check many times, but find no register config problem. I have studied MPC5777M RM for TXBRP register.Still I am not able to understand why it is becoming.PetrS 

[Hal_9000]

Hi @PetrS  @bwp530 

I met the same problem when I debug the  Example MPC5777M MCAN simple TX/RX GHS614 in the SRAM on MPC57xx Motherboard.

I debug this project in S32DS.

I added other module like LINFlex_Uart in this project , and it works normally , so I confirmed the project debug correctly.

Then I set the MCAN1 as external loop back mode , it works normally . I measured MCAN1TX and MCAN1 RX when I using Oscilloscope , I get the same wave in MCAN1RX and MCAN1TX , according to MCAN section in MPC577M RM , it seems like working correctly in external loopback mode.

But when I connect the MCAN1 TX RX and MCAN2 TX RX pin to TJA1041T , I met the same problem like the author met . The MCAN1 TX is pending when I send the second frame. And the MCAN TX and RX have no wave . The CANH and CANL pin keep 2.5V all the time.  

I measured the VI/O , VBAT , VCC, WAKE , STB , EN pin voltage in two TJA1041T on board , it seems nothing  unnormal.

I try to set baudrate as 250kbps , 500kbps , nothing changed.

I guess it may be a HW problem , then I change another board , but I get the same appearance.

Please give me some advice checking the problem ,Thx!!!

[bwp530]

I try to fix this problem for a week. Maybe I have sloved this  problem. But it's confused me. b55689 PetrS may I have your help?

1. According to debug on MPC5777M EVB, I found that M_CAN_1.CCCR.B.INIT will be set as 1 while start sending first MCAN msg with M_CAN_1.TXBAR.R = 0x01 command, I add some code to reset  M_CAN_1.CCCR.B.INIT, but it can't work while ECR, IR show many errors.

2. I have no idea about this. So I re plug J21 and J23 because there is EN port of transceivers. I re debug on board, and  MCAN codes works on board.

3. Once this problem appears again. I can fix it by 2 step. After fixing it for several times, I found thart sometiomes it is repeatable after power off. But most of time it works fine. very strange. i find no rules for now.

[PetrS]

Hi,

it seems that sometimes after power on the TJA1041 on the EVB detects a failure or similar and so disable transmitter. The MCAN module then detects a bit error and goes to Bus Off and stays in Init mode.  

You should check the local failures flags on ERR output of the transceiver and clear it if needed so the transmitter can be enabled again. The /STB and EN pin of the transceiver are used for this purpose. See more in TJA1041 datasheet http://www.nxp.com/documents/data_sheet/TJA1041.pdf and AN00094http://www.nxp.com/documents/application_note/AN00094.pdf.

Once this is done, MCAN can enter normal mode again.

BR, Petr

[bwp530]

I'm confused for several days, I transplant from  Example MPC5777M MCAN simple TX/RX GHS614 ,  but it can't work on MPC5777M EVB

void SysClk_Init(void)
{
MC_CGM.AC3_SC.B.SELCTL = 0x01; //connect XOSC to the PLL0 input
MC_CGM.AC4_SC.B.SELCTL = 0x01; //connect XOSC to the PLL1 input

// Set PLL0 to 300 MHz with 40MHz XOSC reference
PLLDIG.PLL0DV.R = 0x4002100F; // PREDIV = 1, MFD = 15, RFDPHI = 2, RFDPHI1 = 8

MC_ME.RUN_MC[0].R = 0x00130070; // RUN0 cfg: IRCON,OSC0ON,PLL0ON,syclk=IRC

// Mode Transition to enter RUN0 mode:
MC_ME.MCTL.R = 0x40005AF0; // Enter RUN0 Mode & Key
MC_ME.MCTL.R = 0x4000A50F; // Enter RUN0 Mode & Inverted Key
while (MC_ME.GS.B.S_MTRANS) {}; // Wait for mode transition to complete
while(MC_ME.GS.B.S_CURRENT_MODE != 4) {}; // Verify RUN0 is the current mode

// Set PLL1 to 600 MHz with 40MHz XOSC reference
PLLDIG.PLL1DV.R = 0x0001001E; // MFD = 30, RFDPHI = 1

MC_ME.RUN_PC[0].R = 0x000000FE; // enable peripherals run in all modes
MC_ME.RUN_MC[0].R = 0x001300F4; // RUN0 cfg: IRCON, OSC0ON, PLL1ON, syclk=PLL1

MC_CGM.SC_DIV_RC.R = 0x00000001; //! System clock divider ratios will change with next update. Not required for Cut 1.
MC_CGM.DIV_UPD_TYPE.R = 0x80000000; //! System clock divider ratios updated on writing MC_CGM.DIV_UPD_TRIG. Not required for Cut 1.

MC_CGM.SC_DC2.R = 0x800B0000; // PBRIDGEA/PBRIDGEB_CLK at syst clk div by 12 ... (50 MHz)
MC_CGM.SC_DC1.R = 0x80050000; // SXBAR_CLK at syst clk div by 6 ... (100 MHz)
MC_CGM.SC_DC0.R = 0x80020000; // FXBAR_CLK, BD_CLK, IOP_CLK at syst clk div by 3 (200 MHz)
MC_CGM.SC_DC3.R = 0x80010000; // COMP/CHKR_CLK at syst clk div by 2 ... (300 MHz)
MC_CGM.SC_DC4.R = 0x800A0000; // CLKOUT at syst clk div by 11 ... (54.55 MHz)

MC_CGM.DIV_UPD_TRIG.R = 0xfeedface; //! System clock divider ratio updates triggered. Not required for Cut 1.
while (MC_CGM.DIV_UPD_STAT.B.SYS_UPD_STAT == 1) //! Wait for System Clock Divider Update Status == 0. Not required for Cut 1.
{

}

MC_ME.PCTL15.R = 0;
MC_ME.PCTL70.R = 0;
MC_ME.PCTL69.R = 0;
MC_ME.PCTL74.R = 0;

// Mode Transition to enter RUN0 mode:
MC_ME.MCTL.R = 0x40005AF0; // Enter RUN0 Mode & Key
MC_ME.MCTL.R = 0x4000A50F; // Enter RUN0 Mode & Inverted Key
while (MC_ME.GS.B.S_MTRANS) {}; // Wait for mode transition to complete
while(MC_ME.GS.B.S_CURRENT_MODE != 4) {}; // Verify RUN0 is the current mode

MC_CGM.AC0_SC.R = 0x02000000; // Select PLL0 for auxiliary clock 0
MC_CGM.AC0_DC0.R = 0x80050000; // PER_CLK : Enable aux clk 0 div by 6 (50 MHz)
MC_CGM.AC8_SC.R = 0x01000000; // Select XOSC for auxiliary clock 8
MC_CGM.AC8_DC0.R = 0x80000000; // CAN_CLK : Enable aux clk 8 div by 1 (40 MHz)

}

static void MCAN_MSG_RAM_Init(void)
{
int i;
uint32_t *pMsgRAM = (uint32_t*)MCAN_MSG_RAM_BASE_ADDR;

for(i=0;i<MCAN_MSG_RAM_LENGTH/4;i++)
{
*pMsgRAM++ = 0x0;
}
}

static void M_CAN_1_Init(void)
{
/* 1. put module to Init mode*/

M_CAN_1.CCCR.B.INIT = 0x1;
while(M_CAN_1.CCCR.B.INIT == 0)
{

}

//2. enable CCE bit to change config
M_CAN_1.CCCR.B.CCE = 0x1;
while(M_CAN_1.CCCR.B.CCE==0)
{

}

M_CAN_1.CCCR.B.CMR = 0x0; //No CAN FD
M_CAN_1.CCCR.B.CME = 0x0;

//M_CAN_1.BTP.R = 0x00011E77; // Set time quanta for 0.5Mbps SYNC=1, TSEG1=30+1, TSEG2=7+1, SJW=7+1
M_CAN_1.BTP.R = 0x000117DD; // Set time quanta for 0.5Mbps SYNC=1, TSEG1=23+1, TSEG2=13+1, SJW=13+1

M_CAN_1.GFC.R = (0
| 3<<4 // Reject non-matching standard frames in Rx FIFO 0
| 3<<2 // Reject non-matching extended frames in Rx FIFO 1
| 1<<1 // Reject Remote Frames Standard
| 1); // Reject Remote Frames Extended

M_CAN_1.TXBC.R = (0 // tx buffer
| 2 << 16 // space for 2 messages
| MCAN1_TXBC_TBSA); // starting at offset MCAN0_TXBC_TBSA

M_CAN_1.RXESC.R = 0x00000000; //set for 8 data bytes both RX FIFO 0 and FIFO 1
M_CAN_1.TXESC.R = 0x00000000; //set for 8 data bytes tx buffer

M_CAN_1.CCCR.B.CCE = 0x0;
M_CAN_1.CCCR.B.INIT = 0x0; //re-enable CCCR protection
while((M_CAN_1.CCCR.R & 0x1)==1)
{

}

}

static void M_CAN_2_Init(void)
{

// put module to Init mode
M_CAN_2.CCCR.B.INIT = 0x1;
while(M_CAN_2.CCCR.B.INIT == 0)
{

}

// enable CCE bit to change config
M_CAN_2.CCCR.B.CCE = 0x1;
while(M_CAN_2.CCCR.B.CCE==0)
{

}

M_CAN_2.CCCR.B.CMR = 0x0; //no CAN FD
M_CAN_2.CCCR.B.CME = 0x0;

//M_CAN_2.BTP.R = 0x00011E77; // Set time quanta for 0.5Mbps SYNC=1, TSEG1=30+1, TSEG2=7+1, SJW=7+1
M_CAN_2.BTP.R = 0x000117DD; // Set time quanta for 0.5Mbps SYNC=1, TSEG1=23+1, TSEG2=13+1, SJW=13+1

M_CAN_2.GFC.R = (0
| 0<<4 // Accept non-matching standard frames in Rx FIFO 0
| 1<<2 // Accept non-matching extended frames in Rx FIFO 1
| 1<<1 // Reject Remote Frames Standard
| 1); // Reject Remote Frames Extended

M_CAN_2.SIDFC.R = (0
| 2 << 16 // 2 standard message ID filter elements
| MCAN2_SIDFC_FLSSA); // filter list starting from offset MCAN1_SIDFC_FLSSA

M_CAN_2.XIDFC.R = (0
| 2 << 16 // 2 Extended ID's filter used in this network
| MCAN2_XIDFC_FLESA); // filter list starting from offset MCAN1_XIDFC_FLESA

M_CAN_2.RXF0C.R = (0
| 1 << 31 // FIFO0 overwrite
| 2 << 16 // hold 2 messages
| MCAN2_RXF0C_F0SA); // starting at offset MCAN1_RXF0C_F0SA

M_CAN_2.RXF1C.R = (0
| 1 << 31 // FIFO1 overwrite
| 2 << 16 // hold 2 messages
| MCAN2_RXF1C_F1SA); // starting at offset MCAN1_RXF1C_F1SA

M_CAN_2.RXESC.R = 0x00000000; //set for 8 data bytes both RX FIFO 0 and FIFO 1
M_CAN_2.TXESC.R = 0x00000000; //set for 8 data bytes tx buffer

M_CAN_2.CCCR.B.CCE = 0x0;
M_CAN_2.CCCR.B.INIT = 0x0; //re-enable CCCR protection
while((M_CAN_2.CCCR.B.INIT & 0x1)==1)
{

}

}

void MCAN_ID_init()
{

//MCAN2 std ID table MCAN1_SIDFC_FLSSA
WRITE_MSG_RAM( MCAN2_SIDFC_FLSSA,
0 // Standard Message ID filter element 1
| 0x2<<30 // Classic filter: SFID1 = filter (ID), SFID2 = mask
| 0x1<<27 // Store in Rx FIFO 0 if filter matches
| 0x123<<16 // ID = 0x123
| 0x7FF); // mask = 0x7FF

WRITE_MSG_RAM( MCAN2_SIDFC_FLSSA + 0x04,
0 // Standard Message ID filter element 2
| 0x2<<30 // Classic filter: SFID1 = filter (ID), SFID2 = mask
| 0x1<<27 // Store in Rx FIFO 0 if filter matches
| 0x456<<16 // ID = 0x456
| 0x7FF); // mask = 0x7FF

//MCAN1 ext ID table at offset MCAN2_XIDFC_FLESA
WRITE_MSG_RAM( MCAN2_XIDFC_FLESA,
0 // extended Message ID filter element 1, word F0
| 0x2<<29 // Store in Rx FIFO 1 if filter matches
| 0x123); // ID = 0x123

WRITE_MSG_RAM( MCAN2_XIDFC_FLESA + 0x04,
0 // extended Message ID filter element 1, word F1
| 0x2<<30 // Classic filter: EFID1 = filter (ID), EFID2 = mask
| 0x1FFFFFFF); // mask = 0x1FFFFFFF

WRITE_MSG_RAM( MCAN2_XIDFC_FLESA + 0x08,
0 // extended Message ID filter element 2, word F0
| 0x2<<29 // Store in Rx FIFO 1 if filter matches
| 0x456); // ID = 0x123

WRITE_MSG_RAM( MCAN2_XIDFC_FLESA + 0x0C,
0 // extended Message ID filter element 2, word F1
| 0x2<<30 // Classic filter: EFID1 = filter (ID), EFID2 = mask
| 0x1FFFFFFF); // mask = 0x1FFFFFFF
}

static void M_CAN_1_TransmitMsg(uint8_t ext, uint32_t ID, uint8_t lenght)
{
uint32_t txID;

if (ext==0) txID = ID<<18;
else txID = ID;

if (M_CAN_1.TXBRP.R == 0)
{

int z;

WRITE_MSG_RAM( MCAN1_TXBC_TBSA,
0 // Tx Buffer 0 T0 word
| ext<<30 // standard ID
| 0<<29 // transmit data frame
| txID); // message ID

WRITE_MSG_RAM( MCAN1_TXBC_TBSA + 4,
0 // Tx Buffer 0 T1 word
| 0<<23 // do not store TX event
| (lenght << 16)); // dlc... data length

for(z = 0; z < lenght; z+=4) // fill rest of Tx Buffer 0 Tn words with data
{
WRITE_MSG_RAM( MCAN1_TXBC_TBSA + 8 + z, M_CAN_1_data[z] | (M_CAN_1_data[z+1]<<8) | (M_CAN_1_data[z+2]<<16) | (M_CAN_1_data[z+3]<<24));
}

M_CAN_1.TXBAR.R = 0x1; // start transmission for M_CAN0 TX buffer 0
}
}

static void M_CAN_2_Read_RXFIFO(uint8_t fifo)
{
uint32_t temp = 0;
uint8_t dlc,i=0,j=3;
uint8_t get_index; // index of FIFO element to be read
uint16_t fifo_item_offset ; // real offset in msg RAM, 2 word + 8 bytes of data
uint8_t *pRXdata = &M_CAN_2_data[0];

if(fifo)
{
get_index = M_CAN_2.RXF1S.B.F1GI; // index of FIFO element to be read
fifo_item_offset = MCAN2_RXF1C_F1SA + 16 * get_index; // real offset in msg RAM, 2 word + 8 bytes of data
}
else
{
get_index = M_CAN_2.RXF0S.B.F0GI; // index of FIFO element to be read
fifo_item_offset = MCAN2_RXF0C_F0SA + 16 * get_index; // real offset in msg RAM, 2 word + 8 bytes of data
}

// read message word R0 from RXFIFO 0
temp = READ_MSG_RAM( fifo_item_offset + 0);
// read message word R1 from RXFIFO 0
temp = READ_MSG_RAM( fifo_item_offset + 4);

dlc = (temp&0x000F0000)>>16; // get number of received bytes

while(dlc--) // read dlc bytes from FIFO
{
*pRXdata++ = READ_MSG_RAM_8bit( fifo_item_offset + 8 + i + j);
if(j==0) j=4,i+=4;
j--;
}

if(fifo) M_CAN_2.RXF1A.R = get_index; // acknowledge the reading of RXFIFO "get_index" element
else M_CAN_2.RXF0A.R = get_index; // acknowledge the reading of RXFIFO "get_index" element

/* do someting with the received data */
/* drive the output pin with the received data */
SIUL2.GPDO[4].R = M_CAN_2_data[0];
}