can.c

Pic18F458的Can通信模块代码

/*********************************************************************
 *
 *   This file contains CAN drivers for PIC18Fxx8 devices
 *   
 *********************************************************************
 * FileName:        CAN.C
 * Dependencies:    CAN.H, PIC18.H or P18CXXX.H
 * Processor:       PIC18FXX8
 * Compiler:        MCC18 v2.20 or higher
 *                  HITECH PICC-18 v8.20PL4 or higher
 * Linker:          
 * Company:         Microchip Technology, Inc.
 *
 * Software License Agreement
 *
 * The software supplied herewith by Microchip Technology Incorporated
 * (the "Company") is intended and supplied to you, the Company抯
 * customer, for use solely and exclusively with products manufactured
 * by the Company. 
 *
 * The software is owned by the Company and/or its supplier, and is 
 * protected under applicable copyright laws. All rights are reserved. 
 * Any use in violation of the foregoing restrictions may subject the 
 * user to criminal sanctions under applicable laws, as well as to 
 * civil liability for the breach of the terms and conditions of this 
 * license.
 
 * THIS SOFTWARE IS PROVIDED IN AN "AS IS" CONDITION. NO WARRANTIES, 
 * WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED 
 * TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 
 * PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE COMPANY SHALL NOT, 
 * IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR 
 * CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
 *
 *
 *
 *
 * Author               Date        Comment
 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * Thomas Castmo        06/07/2003  Initial release
 * Thomas Castmo        07/07/2003  Cleared up a bit and implemented 
 *                                  the window function CANCON<3:1> 
 *                                  for interrupts
 * Thomas Castmo        16/07/2003  Added support for the Microchip
 *                                  MPLAB C18 compiler
 * 
 ********************************************************************/
#include "can.h"

#if defined(HI_TECH_C)
    #if defined(_MPC_)
        #define HITECH_C18
    #else
        #error "Unknown part is selected."
    #endif
#else
    #define MCHP_C18
#endif

#if defined(MCHP_C18) && defined(HITECH_C18)
#error "Invalid Compiler selection."
#endif

#if !defined(MCHP_C18) && !defined(HITECH_C18)
#error "Compiler not supported."
#endif


#if defined(HITECH_C18)
#include <pic18.h>

#elif defined(MCHP_C18)
#include <p18cxxx.h>

#define TRISB2 TRISBbits.TRISB2
#define TRISB3 TRISBbits.TRISB3
#define TXB0REQ TXB0CONbits.TXREQ
#define RXB0FUL RXB0CONbits.RXFUL
#define RXB0RTRRO RXB0CONbits.RXRTRRO

#define RXB0IF PIR3bits.RXB0IF
#define RXB1IF PIR3bits.RXB1IF
#define TXB0IF PIR3bits.TXB0IF
#define TXB1IF PIR3bits.TXB1IF
#define TXB2IF PIR3bits.TXB2IF
#define ERRIF PIR3bits.ERRIF
#define WAKIF PIR3bits.WAKIF

#define RXB0IE PIE3bits.RXB0IE
#define RXB1IE PIE3bits.RXB1IE
#define TXB0IE PIE3bits.TXB0IE
#define TXB1IE PIE3bits.TXB1IE
#define TXB2IE PIE3bits.TXB2IE
#define ERRIE PIE3bits.ERRIE
#define WAKIE PIE3bits.WAKIE


#endif



#define CONFIG_MODE 0x9F
#define LISTEN_MODE 0x7F 
#define LOOPBACK_MODE 0x5F 
#define DISABLE_MODE 0x3F  
#define NORMAL_MODE 0x1F
#define MODE_MASK 0xE0

#define NoInterrupt 0x00
#define ErrorInterrupt 0x02
#define TXB2Interrupt 0x04
#define TXB1Interrupt 0x06
#define TXB0Interrupt 0x08
#define RXB1Interrupt 0x0A
#define RXB0Interrupt 0x0C
#define WakeUpInterrupt 0x0E


#ifdef CAN_ERROR_HANDLER_ENABLE
extern void CANErrorHandler(void);
#define CAN_INT_BITS 0x3F	//CAN interrupts which should be enabled, simply what PIE3 is to be loaded with (Note all TXB IE will be set regardless of this value)
#else
#define CAN_INT_BITS 0x1F	//CAN interrupts which should be enabled, simply what PIE3 is to be loaded with (Note all TXB IE will be set regardless of this value)
#endif
/*
union RXBuffer {				//接收缓冲区结构
	unsigned char Data[14];		//It has to be a bit messy/strict for
	struct {					//it to go trough the PICC18 compiler
		union {
			unsigned char Byte;
			struct {
				unsigned FILHIT0:1;
				unsigned JTOFF:1;
				unsigned RXB0DBEN:1;
				unsigned RXRTRRO:1;
				unsigned :1;
				unsigned RXM0:1;
				unsigned RXM1:1;
				unsigned RXFUL:1;
			} Bits;
		} RXBCON;
		union {
			unsigned char Byte;
		} RXBSIDH;
		union {
			unsigned char Byte;
			struct {
				unsigned EID16:1;
				unsigned EID17:1;
				unsigned :1;
				unsigned EXID:1;
				unsigned SRR:1;
				unsigned SID0:1;
				unsigned SID1:1;
				unsigned SID2:1;
			} Bits;
		} RXBSIDL;
		union {
			unsigned char Byte;
		} RXBEIDH;
		union {
			unsigned char Byte;
		} RXBEIDL;
		union {
			unsigned char Byte;
			struct {
				unsigned DLC0:1;
				unsigned DLC1:1;
				unsigned DLC2:1;
				unsigned DLC3:1;
				unsigned RB0:1;
				unsigned RB1:1;
				unsigned RXRTR:1;
				unsigned :1;
			} Bits;
		} RXBDLC;
		union {
			unsigned char Array[8];
			struct {
				unsigned char RXBD0;
				unsigned char RXBD1;
				unsigned char RXBD2;
				unsigned char RXBD3;
				unsigned char RXBD4;
				unsigned char RXBD5;
				unsigned char RXBD6;
				unsigned char RXBD7;
			} Bytes;
		} RXBD;
	} Specific;
};

union TXBuffer {					//发送缓冲区结构
	unsigned char Data[14];
	struct {
		union {
			unsigned char Byte;
			struct {
				unsigned TXPRI0:1;
				unsigned TXPRI1:1;
				unsigned :1;
				unsigned TXREQ:1;
				unsigned TXERR:1;
				unsigned TXLARB:1;
				unsigned TXABT:1;
			} Bits;
		} TXBCON;
		union {
			unsigned char Byte;
		} TXBSIDH;
		union {
			unsigned char Byte;
			struct {
				unsigned EID16:1;
				unsigned EID17:1;
				unsigned :1;
				unsigned EXIDE:1;
				unsigned :1;
				unsigned SID0:1;
				unsigned SID1:1;
				unsigned SID2:1;
			} Bits;
		} TXBSIDL;
		union {
			unsigned char Byte;
		} TXBEIDH;
		union {
			unsigned char Byte;
		} TXBEIDL;
		union {
			unsigned char Byte;
			struct {
				unsigned DLC0:1;
				unsigned DLC1:1;
				unsigned DLC2:1;
				unsigned DLC3:1;
				unsigned :1;
				unsigned :1;
				unsigned TXRTR:1;
				unsigned :1;
			} Bits;
		} TXBDLC;
		union {
			unsigned char Array[8];
			struct {
				unsigned char TXBD0;
				unsigned char TXBD1;
				unsigned char TXBD2;
				unsigned char TXBD3;
				unsigned char TXBD4;
				unsigned char TXBD5;
				unsigned char TXBD6;
				unsigned char TXBD7;
			} Bytes;
		} TXBD;
	} Specific;
};
*/
union RXBuffer RXMessage[RXBUF];		//接收缓冲结构数组(相当于几桢的消息)RXBUF指定缓冲大小（8）
union TXBuffer TXMessage[TXBUF];		//接收缓冲结构数组(相当于几桢的消息)TXBUF指定缓冲大小（8）
char RXRPtr = 0;						//接收缓冲数组的读指针
char RXWPtr = 0;						//接收缓冲数组的写指针
char TXRPtr = 0;						//发送缓冲数组的读指针用于记录缓冲区的读出位置(读出后写入发送寄存器 ) 
char TXWPtr = 0;						//发送缓冲数组的写指针用于记录缓冲区的写入位置(及消息写入缓冲的位置)


/*********************************************************************
 * Function:        void CANGetMessage(void)
 *
 * PreCondition:    <WIN2:WIN0> in the CANCON register has to set
 *                  to reflect the desired RXB registers
 *
 * Input:           None
 *
 * Output:          None
 *
 * Side Effects:    Will modify the RX FIFO Write pointer (RXWPtr)
 *
 * Overview:        Gets the registers for a RXB and puts them in the
 *                  CAN Receive buffer
 *