KEA128的CAN收发程序

byxzwz · 发表于 2020-3-7 11:19:53

本帖最后由 byxzwz 于 2020-3-12 14:11 编辑

新手虽然水到高级会员哈哈一个简单的KEA128的CAN收发程序希望能帮到有需要的人
过程中用到的资料也会发上来
话不多说上代码

uint8_t rec_data[8]={0};
void CAN_Init(uint8_t clk,uint8_t sjw,uint8_t brp,uint8_t tseg1,uint8_t tseg2)
{
      //MSCAN的引脚复用选择CAN_TX为PTC7，CAN_RX为PTC6
      SIM_PINSEL1 &= ~SIM_PINSEL1_MSCANPS_MASK;
      //MSCAN模块时钟门控制；SIM_SCGC的MSCAN位=1：使能总线给MSCAN时钟；
      //SIM_SCGC的MSCAN位=0：禁止总线给MSCAN时钟
      SIM_SCGC |= SIM_SCGC_MSCAN_MASK;

      //MSCAN12模块使能
      MSCAN_CANCTL1 |= MSCAN_CANCTL1_CANE_MASK;

      //0 MSCAN 时钟源是振荡器时钟。
      //1 MSCAN 时钟源是总线时钟。
      if(1 == clk)
            MSCAN_CANCTL1 |= MSCAN_CANCTL1_CLKSRC_MASK;
      else
            MSCAN_CANCTL1 &= ~MSCAN_CANCTL1_CLKSRC_MASK;

      //禁止侦听模式，即开启正常模式
      MSCAN_CANCTL1 &= ~MSCAN_CANCTL1_LISTEN_MASK;

      //进入初始化模式
      MSCAN_CANCTL0 |= MSCAN_CANCTL0_INITRQ_MASK;
      //等待应答进入初始化模式
      while((MSCAN_CANCTL1 & MSCAN_CANCTL1_INITAK_MASK)== 0);

      //使用2个32位接收过滤器，查阅芯片手册寄存器MSCAN_CANIDAC
      MSCAN_CANIDAC &= ~MSCAN_CANIDAC_IDAM_MASK;

      //如果不设置为0xff，就需要对每一位进行过滤
      //0为需要过滤 1为不需要过滤
      MSCAN_BASE_PTR->CANIDAR_BANK_1[0]=0xff;
      MSCAN_BASE_PTR->CANIDAR_BANK_1[1]=0xff;
      MSCAN_BASE_PTR->CANIDAR_BANK_1[2]=0xff;
      MSCAN_BASE_PTR->CANIDAR_BANK_1[3]=0xff;

      MSCAN_BASE_PTR->CANIDMR_BANK_1[0]=0xff;
      MSCAN_BASE_PTR->CANIDMR_BANK_1[1]=0xff;
      MSCAN_BASE_PTR->CANIDMR_BANK_1[2]=0xff;
      MSCAN_BASE_PTR->CANIDMR_BANK_1[3]=0xff;

      MSCAN_BASE_PTR->CANIDAR_BANK_2[0]=0xff;
      MSCAN_BASE_PTR->CANIDAR_BANK_2[1]=0xff;
      MSCAN_BASE_PTR->CANIDAR_BANK_2[2]=0xff;
      MSCAN_BASE_PTR->CANIDAR_BANK_2[3]=0xff;

      MSCAN_BASE_PTR->CANIDMR_BANK_2[0]=0xff;
      MSCAN_BASE_PTR->CANIDMR_BANK_2[1]=0xff;
      MSCAN_BASE_PTR->CANIDMR_BANK_2[2]=0xff;
      MSCAN_BASE_PTR->CANIDMR_BANK_2[3]=0xff;

      //波特率配置（按照公式：波特率=clk/（（1+tseg1+tseg2）*分频因数（BRP+1）））
      //有几点需要注意的 1+tseg1+tseg2的范围[8,25]
      MSCAN_CANBTR0 = MSCAN_CANBTR0_SJW(sjw) ;
      MSCAN_CANBTR0 = MSCAN_CANBTR0_BRP(brp);
      MSCAN_CANBTR1 = MSCAN_CANBTR1_TSEG1(tseg1);
      MSCAN_CANBTR1 = MSCAN_CANBTR1_TSEG2(tseg2);
      MSCAN_CANBTR1 &= ~MSCAN_CANBTR1_SAMP_MASK;

      //退出初始化模式
      MSCAN_CANCTL0 &= ~MSCAN_CANCTL0_INITRQ_MASK;
      while((MSCAN_CANCTL1 & MSCAN_CANCTL1_INITAK_MASK) == 1);

      //CAN 模块使能
      MSCAN_CANCTL1 |= MSCAN_CANCTL1_CANE_MASK;
}

void CAN_Send(uint32_t mscan_addr,const uint8_t * mscan_data,uint8_t mscan_dlr,uint8_t mscan_ide)
{
      uint8_t u8TransmitterEmptyFlag;
      //read MSCAN_CANTFLG_TXE register ==> able use cache
      u8TransmitterEmptyFlag = MSCAN_CANTFLG & MSCAN_CANTFLG_TXE_MASK;
      //select transmitter channel
      MSCAN_CANTBSEL = MSCAN_CANTBSEL_TX(u8TransmitterEmptyFlag);
      if(mscan_ide == 1){
      //allocation address
      MSCAN_TEIDR0 = ((mscan_addr>>21)&0xff);
      MSCAN_TEIDR1 = ((mscan_addr>>13)&0xe0)|0x18|((mscan_addr>>15)&0x07);
      MSCAN_TEIDR2 = ((mscan_addr>>7)&0xff);
      MSCAN_TEIDR3 = ((mscan_addr<<1)&0xfe);
      }

      if(mscan_ide == 0){
            MSCAN_TSIDR0 = (mscan_addr >> 3) & 0xff ;//前3位数据不要 TSIDR1：10-3 数据>>3 & 0xff（&为了准确赋值寄存器）
            MSCAN_TSIDR1 = (mscan_addr << 5) & 0xe0 ;//前3位数据放到TSIDR0的后3位 TSIDR0：2-0  数据<<5 & 0xe0（&为了准确赋值寄存器）
      }
      //allocation data
      memcpy((void *)&MSCAN_TEDSR0,(void *)mscan_data,mscan_dlr);
      MSCAN_TDLR       = mscan_dlr;
      MSCAN_TBPR = 0;
      MSCAN_CANTFLG = (MSCAN_CANTBSEL&MSCAN_CANTBSEL_TX_MASK)&0x07;
}

uint8_t CAN_Receive()
{
if( (MSCAN_CANRFLG & 0x01) == 0)// (CAN0RFLG_RXF == 0)
{
      return 1;  //未接收到帧
}
      if((MSCAN_CANRFLG & 0x01) == 1)  //判断是否接收到数据
      {
            uint8_t i = 0 ;
            if((MSCAN_RSIDR1 & 0x08) == 0)
            for(i = 0 ; i < (MSCAN_RDLR & 0x0f) ; i ++)
            {
                     rec_data = MSCAN_REDSR(i) ;
            }
            return re_success ;
      }
      MSCAN_CANRFLG = 1 ;
      return no_infor ;          //无接收数据
}

阅读全文