mscan.c

基于FREESCALE单片机9S08DZ60的CAN的应用层源代码.开发环境为CODEWARRIOR FOR HC08

/*******************************************************************************/
/**
Copyright (c) 2007 Freescale Semiconductor
\file       MSCAN.c
\brief      Driver for basic MSCAN functions
\author     Freescale Semiconductor
\author     B05114
\version    0.1
\date       January/ 2008
*/
/*******************************************************************************/

/** Derivative information */ 
#include "derivative.h"    

/** MSCAN definitions */
#include "MSCAN.h"
   
extern UINT8 RxData[8];    /* Reception array */

/*******************************************************************************/
/**
* \brief    MSCAN configuration, baud rate = 500kbps, 16 bit acceptance filters
* \author   B05114
* \param    void
* \return   void
*/
void MSCAN_Init(void) 
{        
    CANCTL0_INITRQ = 1;    /* MSCAN in initialization mode */
        while (!(CANCTL1_INITAK))
            ;	        /* Wait for initialization mode acknowledge */
            
    CANCTL1_CANE = 1;      /* Enable MSCAN module */        
    
    CANCTL1_CLKSRC = CAN_CLK;    /* Clock source selection */    
    CANCTL1_LOOPB = 0;          /* Set to 1 for LoopBack Mode, 0 otherwise */
    CANCTL1_LISTEN = 0;         /* Not listen only mode */            
                                                                              
    CANBTR1_TSEG_10 = TIME_SEGM1;    /* Time Segment 1 */
    CANBTR1_TSEG_20 = TIME_SEGM2;    /* Time Segment 2 */                             
                                    
    CANBTR0_BRP = CAN_PRESC;    /* Baud rate prescaler */  
    CANBTR0_SJW = CAN_SYNJW;    /* Sinchronization jump width */       
                                              
    CANBTR1_SAMP = 0;      /* One sample per bit */	      
             
    CANIDAC_IDAM = 0x01;               /* Four 16-bit acceptance filters */                                                          
    
    CANIDAR0 = ACC_CODE_ID_HIGH;        /* 16 bit Filter 0 */
    CANIDMR0 = MASK_CODE_ST_ID_HIGH;   
    CANIDAR1 = ACC_CODE_ID_LOW;     
    CANIDMR1 = MASK_CODE_ST_ID_LOW;    
    
    CANIDAR2 = 0x00;                   /* 16 bit Filter 1 */
    CANIDMR2 = MASK_CODE_ST_ID_HIGH;   
    CANIDAR3 = 0x00;                   
    CANIDMR3 = MASK_CODE_ST_ID_LOW;    
    
    CANIDAR4 = 0x00;                   /* 16 bit Filter 2 */
    CANIDMR4 = MASK_CODE_ST_ID_HIGH;   
    CANIDAR5 = 0x00;                   
    CANIDMR5 = MASK_CODE_ST_ID_LOW;    
    
    CANIDAR6 = 0x00;                   /* 16 bit Filter 3 */
    CANIDMR6 = MASK_CODE_ST_ID_HIGH;   
    CANIDAR7 = 0x00;                   
    CANIDMR7 = MASK_CODE_ST_ID_LOW;    
    
    
    CANCTL0_INITRQ = 0;            /* Exit initialization mode request */
        while (CANCTL1_INITAK)
            ;               	/* Wait for normal mode */
                   
        while(!(CANCTL0_SYNCH))
            ;                   /* Wait for CAN synchronization */
   
    CANRFLG_RXF = 1;       /* Clear receiver flags */                                   
    CANRIER_RXFIE = 1;     /* Enable Full Receive Buffer interrupt */
                                  
}

/*******************************************************************************/
/**
* \brief    CAN frame transmission
* \author   B05114
* \param    CAN_ID: Identifier           \n 
            Msg_Prio: Priority            \n
            Msg_Length: Frame size        \n 
            CANTxData: Data array
* \return   void
*/
UINT8 MSCAN_SendFrame(UINT32 CAN_ID, UINT8 Msg_Prio, UINT8 Msg_Length, UINT8 *CANTxData)
{   
    /* Transmission buffer */
    UINT8 TxBuffer = {0};
    
    /* Index to data within the transmission buffer */ 
    UINT8 Index;
    
    if (!CANTFLG)              /* Retrun if Transmit Buffer is full */
        return ERR_BUFFER_FULL;

    CANTBSEL = CANTFLG;       /* Select lowest empty buffer */
    TxBuffer = CANTBSEL;		/* Backup selected buffer */
    
    
    *((UINT32 *) ((UINT32)(&CANTIDR0)))= CAN_ID;   /* Load Id to IDR Registers */
        
        /* Load data to Data Segment Registers */
        for (Index=0;Index<Msg_Length;Index++) {
            *(&CANTDSR0 + Index) = CANTxData[Index];  
        }

    CANTDLR = Msg_Length;   /* Set Data Length Code */
    CANTTBPR = Msg_Prio;    /* Set Priority */

    CANTFLG = TxBuffer;  /* Start transmission */
                
        while ( (CANTFLG & TxBuffer) != TxBuffer)
            ;  /* Wait for Transmission completion */
            
    return NO_ERR;
 }

/*******************************************************************************/
/**
* \brief    CAN reception interrupt service routine
* \author   B05114
*/
interrupt void CANRx_ISR(void)
{    
    /* Length of received frame */
    UINT8 Msg_Length;
    
    /* Index for extracting/storing received data */
    UINT8 Index;    

    Msg_Length = (CANRDLR & 0x0F);  /* Extract received frame data length */
	
	    /* Read and store each of the received data */
	    for (Index=0; Index < Msg_Length; Index++)
  	        RxData[Index] = *(&CANRDSR0 + Index); 

    CANRFLG_RXF = 1;   /* Clear reception flag */             
}

/*******************************************************************************/


/*******************************************************************************/
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/*******************************************************************************/