MPC5604B的CAN总线通信

z-bo · 发表于 2015-9-22 15:38:31

/* main.c: FlexCAN program */
/* Description: Transmit one message from FlexCAN 0 buf. 0 to FlexCAN C buf. 1
（从 FlexCAN 0 buf. 0 传递一个消息到FlexCAN C buf. 1）*/

/* Rev 0.1 Jan 16, 2006 S.Mihalik, Copyright Freescale, 2006. All Rights Reserved */

/* Rev 0.2 Jun 6 2006 SM - changed Flexcan A to C & enabled 64 msg buffers */

/* Rev 0.3 Jun 15 2006 SM - 1. Made globals uninitialized */
/*                         2. RecieveMsg function:  read CANx_TIMER, removed setting buffer's CODE*/
/*                         3. added idle loop code for smoother Nexus trace */
/*                         4. modified for newer Freescale header files (r 16) */

/* Rev 0.4 Aug 11 2006 SM - Removed redundant CAN_A.MCR init */

/* Rev 0.5 Jan 31 2007 SM - Removed other redundant CAN_C.MCR init */

/* Rev 0.6 Mar 08 2007 SM - Corrected init of MBs- cleared 64 MBs, instead of 63 */

/* Rev 0.7 Jul 20 2007 SM - Changes for MPC5510 */

/* Rev 0.8 May 15 2008 SM - Changes for new header file symbols */

/* Rev 0.9 May 22 2009 SM - Changes for MPC56xxB/P/S */

/* Rev 1.0 Jul 10 2009 SM - Simplified, cleared CAN Msg Buf flag by writing to reg */

/* not bit, increased Tx pads slew rate(转换率), changed RxCODE, RxLENGTH, dummy data（虚拟数据） types*/
/* & init receiving CAN first to allow CAN bus sync time before receiving 1st msg*/
/* Rev 1.1 Mar 14 2010 SM - modified initModesAndClock, updated header file */
/*  NOTE!! structure canbuf_t in header file modified to allow byte addressing*/
/*Chapter 22*/
#include "MPC5604B_M27V.h" /* Use proper include file */

uint32_t  RxCODE;             /* Received message buffer code */
uint32_t  RxID;                /* Received message ID */
uint32_t  RxLENGTH;          /* Recieved message number of data bytes */
uint8_t RxDATA[8];          /* Received message data string*/
uint32_t  RxTIMESTAMP;       /* Received message time */

void initModesAndClks(void) /*系统初始化*/
{
  ME.MER.R = 0x0000001D;       /* Enable DRUN, RUN0, SAFE, RESET modes */
                              /* Initialize PLL before turning it on: (初始化锁相环)*/
/* Use 1 of the next 2 lines depending on crystal frequency: */
//锁相环时钟没问题
  CGM.FMPLL_CR.R = 0x02400100;
  //0x02400100                /* 8 MHz xtal: Set PLL0 to 64 MHz */
  /*CGM.FMPLL_CR.R = 0x12400100;*/  /* 40 MHz xtal: Set PLL0 to 64 MHz */
  ME.RUN[0].R = 0x001F0074;    /* RUN0 cfg: 16MHzIRCON,OSC0ON,PLL0ON,syclk=PLL */

//  ME.DRUN.R=0x001F0010;

// ME.RUNPC[0].R = 0x000000FE;    /* Peri. Cfg. 1 settings: only run in RUN0 mode */
  ME.RUNPC[0].R = 0x00000010;
/*要什么功能就在PCTL中配置相应的序号*/
/*选择FlexCAN0和FlexCAN1控制*/
  ME.PCTL[16].R = 0x01;          /* P143 MPC56xxB/P/S FlexCAN0: select ME.RUNPC[1] */
  //要和RUNPC保持一致
  ME.PCTL[17].R = 0x01;          /* MPC56xxB/S FlexCAN1:  select ME.RUNPC[1] */
/*选择SIUL控制*/
  ME.PCTL[68].R = 0x01;          /* MPC56xxB/S SIUL:  select ME.RUNPC[1] */
/*此处未进行端口引脚配置*/

//  ME.PCTL[96].R=0x00;
                              /* Mode Transition to enter RUN0 mode: */
  ME.MCTL.R = 0x40005AF0;       /* Enter RUN0 Mode & Key */
  ME.MCTL.R = 0x4000A50F;       /* Enter RUN0 Mode & Inverted Key */
  while (ME.GS.B.S_MTRANS) {}    /* Wait for mode transition to complete */
                              /* Note: could wait here using timer and/or I_TC IRQ */
  while(ME.GS.B.S_CURRENTMODE != 4) {} /* Verify RUN0 is the current mode */
}

void initPeriClkGen(void) /*??*/
//??????????
{
  CGM.SC_DC[1].R = 0x80;    /* MPC56xxB/S: Enable peri set 2 sysclk divided by 1 */

  CGM.OC_EN.R= 1;
  CGM.OCDS_SC.R= 0x22000000;

}

void disableWatchdog(void)
{
  SWT.SR.R = 0x0000c520;    /* Write keys to clear soft lock bit */
  SWT.SR.R = 0x0000d928;
  SWT.CR.R = 0x8000010A;    /* Clear watchdog enable (WEN) */
}

void initCAN_1 (void)    /*初始化CAN_1*/
{
  uint8_t i;

  CAN_1.MCR.R = 0x5000003F;    /* Put in Freeze Mode & enable all 64 msg bufs *//*Module Configuration Register----MCR 模式配置寄存器*/
  CAN_1.CR.R = 0x04DB2006;       /* Configure for 8MHz OSC, 100KHz bit time *//*Control Register---CR 控制寄存器*/
  //0x04DB0006
  for (i=0; i<64; i++)
  {
CAN_1.BUF[i].CS.B.CODE = 0; /* Inactivate all message buffers */    /*Message Buffer--64个信息缓冲寄存器*/
  }
  /*P433*/

  CAN_1.IMRL.B.BUF04M=1;

  CAN_1.BUF[4].CS.B.IDE = 0;    /* MB 4 will look for a standard ID */    /*IDE=0表示Frame format(帧格式) is standard*/
  CAN_1.BUF[4].ID.B.STD_ID = 555; /* MB 4 will look for ID = 555 */          /*ID(帧标识符)*/
  CAN_1.BUF[4].CS.B.CODE = 4;    /* MB 4 set to RX EMPTY */                /*CODE=0x0100表示EMPTY: MB is active and empty.*/
//  CAN_1.RXGMASK.R = 0x1FFFFF10; /* Global acceptance mask */                /*Rx Global Mask Register---RXGMASK*/
  SIU.PCR[42].R = 0x0624;       /* MPC56xxB: Config port C10 as CAN1TX, open drain */
  SIU.PCR[35].R = 0x0103;       /* MPC56xxB: Configure port C3 as CAN1RX */    /*CAN_1的收发送*/
  SIU.PSMI[0].R = 0x00;          /* MPC56xxB: Select PCR 35 for CAN1RX Input */ /*P346*//*因为可以作为CAN1Rx的引脚有三个（PC3 PC11 PF15）这里选择PC3以后，要注释 SIU.PSMI[0].R = 0x00;表明选择的是PC3*/
  CAN_1.MCR.R = 0x0000003F;    /* Negate FlexCAN 1 halt state for  64 MB */
}

void initCAN_0 (void)    /*初始化CAN_0*/
{
  uint8_t i;

  CAN_0.MCR.R = 0x5000003F;    /* Put in Freeze Mode & enable all 64 msg bufs */ /*Freeze Mode(It is enabled when the FRZ bit in the MCR is asserted.)*/

  CAN_0.CR.R = 0x04DB0006;       /* Configure for 8MHz OSC, 100KHz bit time */
  /*怎么配置波特率*/

  for (i=0; i<64; i++)
  {
CAN_0.BUF[i].CS.B.CODE = 0; /* Inactivate all message buffers */
  }

  CAN_0.IMRL.B.BUF00M=1;
  CAN_0.BUF[0].CS.B.IDE = 0;          /* Use standard ID length */  /*IDE=0表示Frame format(帧格式) is standard*/
  CAN_0.BUF[0].ID.B.STD_ID = 555;    /* Transmit ID is 555 */ /*ID(帧标识符)*/
  CAN_0.BUF[0].CS.B.RTR = 0;          /* Data frame, not remote Tx request frame */  /*RTR=0表示Indicates the current MB has a Data Frame to be transmitted(表明当前信息缓冲寄存器将要发送)*/ /*RTR=Remote Transmission Request（远程发送请求）*/
//  CAN_0.RXGMASK.R = 0x1FFFFFFF;

  CAN_0.BUF[0].CS.B.CODE = 8;    /* Message Buffer 0 set to TX INACTIVE */ /*CODE=0x1000表示INACTIVE: MB does not participate in the arbitration process.*/
  SIU.PCR[16].R = 0x0624;       /* MPC56xxB: Config port B0 as CAN0TX, open drain */
  SIU.PCR[17].R = 0x0103;       /* MPC56xxB: Configure port B1 as CAN0RX */ /*CAN_0的收发送*/
  CAN_0.MCR.R = 0x0000003F;    /* Negate FlexCAN 0 halt state for 64 MB */
}
/*发送端配置相对简单(或许在信息发送函数中进行了设置)，只对TX设置为Inactive，而接收端设置比较复杂，比如帧和MB的设置*/
void TransmitMsg (void)    /*发送信息函数*/
{
  uint8_t i;
                                 /* Assumption:  Message buffer CODE is INACTIVE */
  const uint8_t TxData[] = {"Hello"};  /* Transmit string*/
  CAN_0.BUF[0].CS.B.IDE = 0;          /* Use standard ID length */  /*IDE=0表示Frame format(帧格式) is standard*/
  CAN_0.BUF[0].ID.B.STD_ID = 555;    /* Transmit ID is 555 */ /*ID(帧标识符)*/
  CAN_0.BUF[0].CS.B.RTR = 0;          /* Data frame, not remote Tx request frame */  /*RTR=0表示Indicates the current MB has a Data Frame to be transmitted(表明当前信息缓冲寄存器将要发送)*/ /*RTR=Remote Transmission Request（远程发送请求）*/
  CAN_0.BUF[0].CS.B.LENGTH = sizeof(TxData) -1 ; /* # bytes to transmit w/o null */
  for (i=0; i<sizeof(TxData); i++)
  {
CAN_0.BUF[0].DATA.B[i] = TxData[i];    /* Data to be transmitted */  /*DATA表示数据段*/
  }
  CAN_0.BUF[0].CS.B.SRR = 1;          /* Tx frame (not req'd for standard frame)*/  /*SRR=1表示 Recessive value is compulsory for transmission in Extended Format frames（在扩展帧格式下隐形值被强制发送）*/
  CAN_0.BUF[0].CS.B.CODE =0xC;       /* Activate msg. buf. to transmit data frame */ /*RTR=0且CODE=1时Transmit data frame unconditionally once. After transmission, the
MB automatically returns to the INACTIVE state.（发送结束后，MB自动返回到非活跃状态）*/
}
/*发送CAN_0选择缓冲寄存器BUF[0]，接收CAN_1选择缓冲寄存器BUF[1]*/
void RecieveMsg (void)    /*接收信息函数*/
{
  uint8_t j;
  uint32_t dummy;

  while (CAN_1.IFRL.B.BUF04I == 0) {}; /* Wait for CAN 1 MB 4 flag */  /*等待标志位*/
  RxCODE = CAN_1.BUF[4].CS.B.CODE; /* Read CODE, ID, LENGTH, DATA, TIMESTAMP(读取CAN_1的CODE和ID以及Length，Data，Timestamp等参数) */
  RxID    = CAN_1.BUF[4].ID.B.STD_ID;
  RxLENGTH = CAN_1.BUF[4].CS.B.LENGTH;
  for (j=0; j<RxLENGTH; j++)
  {
RxDATA[j] = CAN_1.BUF[4].DATA.B[j];
  }
  RxTIMESTAMP = CAN_1.BUF[4].CS.B.TIMESTAMP;
  dummy = CAN_1.TIMER.R;             /* Read TIMER to unlock message buffers */
  CAN_1.IFRL.R = 0x00000010;          /* Clear CAN 1 MB 4 flag */
}

//void delay_ms(int x)
//{
// int a,b;
// for(a=x;a>0;a--)
// for(b=16000;b>0;b--) ;
//}

void main(void)
{

  volatile uint32_t IdleCtr = 0;

//  delay_ms(1000);

  initModesAndClks();    /* Initialize mode entries */
  initPeriClkGen();       /* Initialize peripheral clock generation for DSPIs */
  disableWatchdog();    /* Disable watchdog */
  initCAN_1();          /* Initialize FLEXCAN 1 & one of its buffers for receive*/
  initCAN_0();          /* Initialize FlexCAN 0 & one of its buffers for transmit*/
// TransmitMsg();          /* Transmit one message from a FlexCAN 0 buffer */
//  RecieveMsg();          /* Wait for the message to be recieved at FlexCAN 1 */
  while (1)
  {
   IdleCtr++; /* Idle loop: increment counter */
   TransmitMsg();          /* Transmit one message from a FlexCAN 0 buffer */
   RecieveMsg();          /* Wait for the message to be recieved at FlexCAN 1 */
  }
}
这个是在找的例程的基础上有部分我修改了，在网上看到帖子说配SBC，不明白什么意思，请前辈给予指点

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