Hi ,I have doubt in RTR that how to set the RTR bit in s32k144 and how to receive the RTR request and sent response? can u kindly help me in this.
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 */
CAN0->MCR |= CAN_MCR_MDIS_MASK; /* MDIS=1: Disable module before selecting clock */
CAN0->CTRL1 &= ~CAN_CTRL1_CLKSRC_MASK; /* CLKSRC=0: Clock Source = oscillator (8 MHz) */
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 = 0x00DB0006; /* Configure for 500 KHz bit time */
/* Time quanta freq = 16 time quanta x 500 KHz bit time= 8MHz */
/* PRESDIV+1 = Fclksrc/Ftq = 8 MHz/8 MHz = 1 */
/* so PRESDIV = 0 */
/* PSEG2 = Phase_Seg2 - 1 = 4 - 1 = 3 */
/* 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 */
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 = 0xFFFFFFFF; /* Global acceptance mask: check all ID bits */
// CAN0->RAMn[ 0*MSG_BUF_SIZE + 0] = 0x0C400000 | 8 <<CAN_WMBn_CS_DLC_SHIFT;
CAN0->RAMn[ 4*MSG_BUF_SIZE + 0] = 0x04000000; /*0000 0100 0101 0000 0000 0000 0000 0000 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[ 0*MSG_BUF_SIZE + 0] = 0x0C500000 | 8 <<CAN_WMBn_CS_DLC_SHIFT;
#ifdef NODE_A /* Node A receives msg with std ID 0x511 */
CAN0->RAMn[ 4*MSG_BUF_SIZE + 1] = 0x14440000; /* Msg Buf 4, word 1: Standard ID = 0x111 */
#else /* Node B to receive msg with std ID 0x555 */
CAN0->RAMn[ 4*MSG_BUF_SIZE + 1] = 0x15540000; /* Msg Buf 4, word 1: Standard ID = 0x555 */
#endif
/* 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) */
}
void FLEXCAN0_transmit_msg(uint32_t sndId,uint8_t *pdata) { /* Assumption: Message buffer CODE is INACTIVE */
CAN0->IFLAG1 = 0x00000001; /* Clear CAN 0 MB 0 flag without clearing others*/
CAN0->RAMn[ 0*MSG_BUF_SIZE + 2] = 0xA5112233; /* MB0 word 2: data word 0 */
CAN0->RAMn[ 0*MSG_BUF_SIZE + 3] = 0x44556677; /* MB0 word 3: data word 1 */
#ifdef NODE_A
// CAN0->RAMn[ 0*MSG_BUF_SIZE + 1] = 0x15540000; /* MB0 word 1: Tx msg with STD ID 0x555 */
CAN0->RAMn[ 0*MSG_BUF_SIZE + 1] = sndId << 18; /* MB0 word 1: Tx msg with STD ID 0x555 */
#else
CAN0->RAMn[ 0*MSG_BUF_SIZE + 1] = 0x14440000; /* MB0 word 1: Tx msg with STD ID 0x511 */
#endif
CAN0->RAMn[ 0*MSG_BUF_SIZE + 0] = 0x0C400000 | 8 <<CAN_WMBn_CS_DLC_SHIFT; /* MB0 word 0: */
/* EDL,BRS,ESI=0: CANFD not used */
/* CODE=0xC: Activate msg buf to transmit */
/* IDE=0: Standard ID */
/* SRR=1 Tx frame (not req'd for std ID) */
/* RTR = 0: data, not remote tx request frame*/
/* DLC = 8 bytes */
}
void FLEXCAN0_receive_msg(uint8_t newDat[8],uint32_t * msgId) { /* Receive msg from ID 0x556 using msg buffer 4 */
uint8_t j;
uint32_t dummy;
RxCODE = (CAN0->RAMn[ 4*MSG_BUF_SIZE + 0] & 0x07000000) >> 24; /* Read CODE field */
// RxID = (CAN0->RAMn[ 4*MSG_BUF_SIZE + 1] & CAN_WMBn_ID_ID_MASK) >> CAN_WMBn_ID_ID_SHIFT ;
*msgId =((CAN0->RAMn[ 4*MSG_BUF_SIZE + 1] & 0x1ffc0000UL) >> 18) ;
RxLENGTH = (CAN0->RAMn[ 4*MSG_BUF_SIZE + 0] & CAN_WMBn_CS_DLC_MASK)>>CAN_WMBn_CS_DLC_SHIFT ;
// RxLENGTH = (CAN0->RAMn[ 4*MSG_BUF_SIZE + 0] & CAN_WMBn_CS_DLC_MASK) >>CAN_WMBn_CS_DLC_MASK ;
for (j=0; j<2; j++) { /* Read two words of data (8 bytes) */
RxDATA[j] = CAN0->RAMn[ 4*MSG_BUF_SIZE + 2 + j];
}
RxTIMESTAMP = (CAN0->RAMn[ 0*MSG_BUF_SIZE + 0] & 0x000FFFF);
dummy = CAN0->TIMER; /* Read TIMER to unlock message buffers */
CAN0->IFLAG1 = 0x00000010; /* Clear CAN 0 MB 4 flag without clearing others*/
}
