can.c

freescale芯片9s12dp256的示例程序

#include <mc9s12c32.h>     /* derivative information */
#include "can.h"
#include "io.h"
#include "pwm.h"
#include "sci.h"
#include "timer.h"
#include "event.h"

#pragma CODE_SEG DEFAULT

// ===================================================================
// Method      : CAN_Init(void)
// Description : CAN Initialization
// Parameters  : None
// Time segment 1: 6
// Time segment 2: 7
// RSJ: 1
// Returns:			 None
// ===================================================================
void CAN_Init(void)
{
	CANCTL0 = 0x01;                      // Set the control register
  CANCTL1 = 0x80;                      // Set the control register 
  CANIDAC_IDAM = 0x00;                 // Set the acceptance mode 
  *(dword *)&CANIDAR0 = 0xFFFFFFFF;    // Set the acceptance code 
  *(dword *)&CANIDAR4 = 0xFFFFFFFF;    // Set the acceptance code 
  *(dword *)&CANIDMR0 = 0xFFFFFFFF;    // Set the acceptance mask 
  *(dword *)&CANIDMR4 = 0xFFFFFFFF;    // Set the acceptance mask 
  CANBTR0 = 0x40;                      // Set the device timing register 
  CANBTR1 = 0x32;                      // Set the device timing register 
  CANCTL1_CLKSRC = 0x00;               // Select the clock source from crystal 
  CANCTL0_INITRQ = 0x00;               // Start device 
  while(CANCTL1_INITAK);               // Wait for device initialization acknowledge 
  while(!CANCTL0_SYNCH);               // Wait for synchronization 
  CANRFLG |= 0xFE;                     // Reset error flags 
  CANRIER = 0xFF;                      // Enable interrupts 
}

// ===================================================================
// Method      : CAN_SendFrame(byte BufferNum,dword MessageID,byte FrameType,byte Length,byte *Data)
// Description : Send a frame.
// Parameters  :
//     MessageID       - Identification of the message
//     FrameType       - Type of frame
//                       DATA_FRAME - data frame   0
//                       REMOTE_FRAME - remote frame  1
//     Length          - Length of the frame in bytes (0..8)
//     * Data            - Pointer to data
// Returns     :			 None
// ===================================================================
void CAN_SendFrame(byte BufferNum,dword MessageID,byte FrameType,byte Length,byte *Data)
{
  byte i;                              /* Temorary variables */
  byte bufmask=((word)1 << BufferNum); /* Buffer mask */

  CANTBSEL = bufmask;                  
  if (MessageID <= 0x7FF)  /* Is it the standard frame? */
    *(dword *)&CANTXIDR0 = (MessageID << 21); /* Sets the message as "standard" */
  else
    *(dword *)&CANTXIDR0 = ( ((MessageID << 1) & 0x0007FFFF) | ((MessageID << 3) & 0xFFE00000) ) | 0x00080000; /* Set the message as "extended" */
  if (FrameType == DATA_FRAME) 
  {       /* Is it a data frame? */
    for(i=0; i<Length; i++)
      *((byte *)&CANTXDSR0 + i) = Data[i]; /* Store data to the transmit register */
    if (MessageID <= 0x7FF) /* Is it the standard frame? */
      CANTXIDR1 &= 0xEF;               /* If yes then set the standard message type as "data frame" */
    else
      CANTXIDR3 &= 0xFE;               /* If no then set the extended message type as "data frame" */
  }
  else 
  {       /* Remote frame */
    if (MessageID <= 0x7FF) /* Is it the standard frame? */
      CANTXIDR1 |= 0x10;               /* If yes then set the standard message type as "remote frame" */
    else
      CANTXIDR3 |= 0x01;               /* If yes then set the extended message type as "remote frame" */
  }
  CANTXDLR = Length;                   /* Set the length of the message */
  CANTXTBPR = 0x00;                    /* Set the priority (high) */
  CANTFLG = bufmask;                 /* Start transmission */
}
	 
// ===================================================================
// Method      :  CAN_ReadFrame(dword *MessageID,byte *FrameType,byte *FrameFormat,byte *Length,byte *Data)
// Description :  Read a frame.
// Parameters  :			         
//    * MessageID       - Pointer to the message indentification
//    * FrameType       - Pointer to a frame type
//                        DATA_FRAME - data frame
//                        REMOTE_FRAME - remote frame
//    * FrameFormat     - Pointer to a frame format
//                        STANDARD_FORMAT - standard frame 11-bits
//                        EXTENDED_FORMAT - extended frame 29-bits
//    * Length          - Pointer to length of the frame
//    * Data            - The buffer for received data
// Returns     :  None
// ===================================================================
void CAN_ReadFrame(dword *MessageID,byte *FrameType,byte *FrameFormat,byte *Length,byte *Data)
{
  byte i;                              /* Temporary variable */
  dword ID;                            /* Temporary variable */

  ID = *(dword *)&CANRXIDR0;           /* Read the identification of the received message */
  if ((CANRXIDR1 & 0x08)) 
  {            /* Is the received message "extended frame" */
    ID = ( ((ID >> 0x01) & 0x0003FFFF) | ((ID >> 0x03) & 0xFFFC0000) ); /* Result the identification */
    *FrameType = (CANRXIDR3 & 0x01)? REMOTE_FRAME : DATA_FRAME; /* Result the frame type */
  } 
  else 
  {                             /* Message is "standard frame" */
    ID >>= 0x15;                       /* Result the identification */
    *FrameType = (CANRXIDR1 & 0x10)? REMOTE_FRAME : DATA_FRAME; /* Result the frame type */
  }
  *MessageID = ID;                     /* Result the identification */
  *FrameFormat = (CANRXIDR1 & 0x08)? EXTENDED_FORMAT : STANDARD_FORMAT; /* Result the frame type */
  *Length = CANRXDLR & 0x0F;           /* Result length of the message */
  if (*FrameType == DATA_FRAME) 
  {      /* Is frame "data frame" */
    for(i=0; i<*Length; i++)
      Data[i] = *((byte *)&CANRXDSR0 + i); /* Return received data */
  }
}

#pragma CODE_SEG __NEAR_SEG NON_BANKED /* Interrupt section for this module. Placement will be in NON_BANKED area. */
interrupt 34 void CAN_FullRxBuffer(void)
{
    CAN_OnFullRxBuffer();             /* If yes then invoke user event */
    CANRFLG_RXF = 1;                  /* Reset the reception complete flag */
}

#pragma CODE_SEG DEFAULT