ccan.asm

pic18f248的CAN通信chengxu

  #INCLUDE <P18F248.INC>
;发送数据是08H

;*************LOCAL MACROS*************** 
CONFIGURE_MODE MACRO
  BSF CANCON,REQOP2
  ENDM
 
NORMAL_MODE  MACRO                                                                                                    
  BCF CANCON,REQOP2 
  BCF CANCON,REQOP1
  BCF CANCON,REQOP0  
  BCF CANCON,ABAT
  ENDM
 

;******************复位矢量中断向量*************
  ORG 000h  
  NOP
  GOTO MAIN


;*****************主程序*************************
MAIN
  CALL CLR_BANK  ;CLEAR ALL BANK 0,1,2,15
  
;**********开始进入传输初始化的设定***************
SETUP
  MOVLB 0FH   ;BANK 15
  MOVLW B'11000000'  ;ENABLE ALL 
  MOVWF INTCON   ;enable gie
  MOVLW B'00000000'  ;  MOVWF PIE3
  CALL SET_PORT  ;set  port
  CALL TXB0_IDENTIFIER  ;TXB0 FILTER
  CALL RXB0_FILTER0  ;RXB0 FILTER0
  CALL BAUD_RATE  ;50KB/S
  NORMAL_MODE   ;NORMAL MODE 

  MOVLW 37   ;发数据，现在是08H
  MOVWF TXB0D0
  BSF TXB0CON,TXREQ
  BTFSS PIR3,TXB0IF  ;判断是否发出去
  GOTO $-2
  BCF PIR3,TXB0IF


STOP
  
  NOP
  GOTO STOP 
  
;******************RXB0 FILTER0****************
;RXB0_FILTER0 
;  STANDARD FRAME 
;PORTA 低五位作为ID的高五位
;*********************************************
RXB0_FILTER0
  CONFIGURE_MODE
  BCF  RXB0CON,RXM1 
  BCF  RXB0CON,RXM0 
  ;0,0 FILTER 有效
  ;0,1 ONLY STANDARD FRAME
  ;1,1 RECEIVE ALL
  ;1,0 ONLY EXTERN  FRAME 
  MOVLW B'10101111'
  MOVWF RXF0SIDH 
   MOVLW b'11100000'
  MOVWF RXF0SIDL
  MOVLW B'11111111'  ;识别位XXXXX000111
  MOVWF RXM0SIDH
  MOVLW B'11111111'  ;全部起作用
  MOVWF RXM0SIDL  ;进行屏蔽位设定，全部为11
  RETURN 

      
;*********设置TXB0  IDENTIFIER***********************
;TXB0_IDENTIFIER
;***************************************************
TXB0_IDENTIFIER
  BCF  TXB0CON,TXPRI1
  BCF  TXB0CON,TXPRI0  ;high interrupt
  MOVLW B'10101111'
  MOVWF TXB0SIDH 
  MOVLW B'11100000'     ;标志位是XXXXX000111
  MOVWF TXB0SIDL
  MOVLW B'00000001' 
  MOVWF TXB0DLC   ;数据帧 6,txrtr是零  
  RETURN 

;***********SET_PORT******************************
SET_PORT
  
  ;********PORTB********
  ;RB0 OUT
  ;RB1 OUT
  ;RB2 OUT TXCAN
  ;RB3 IN RXCAN
  ;RB4 IN 
  ;RB5 IN
  ;RB6  ICD2
  ;RB7  ICD2
  CLRF LATB
  MOVLW B'00001000'
  MOVWF TRISB 
  ;*******PORTC*********
  ;RC0 OUT  RC0-RC7 ALL OUT
  ;RC1 OUT
  ;RC7 OUT
  CLRF LATC
  MOVLW B'00000000'
  MOVWF TRISC 
  RETURN 

;**************BAUD RATE SET******************   
;  FOSC =4MHZ   
;   NOMINAL BIT TIME = 8 TQ
;  TQ=2*(BAUD RATE +1)/FOSC
;  SYN  =1 TQ,PRO=1TQ,PHE1=3TQ,PHE2=3TQ
;  BAUD RATE= 50KB/S
;  BAUD RATE PRESCALER=00100
;   fosc =4mhz MAX_baud rate=250kb/s
;  If fosc=16Mhz ,the max_band=1Mkb/s
;************************************************
BAUD_RATE      ;50KB/S
  CONFIGURE_MODE 
  MOVLW B'00000100'  ;BAUD RATE SET
  MOVWF BRGCON1
  MOVLW B'10010000'
  MOVWF BRGCON2
  MOVLW B'00000010'
  MOVWF BRGCON3  
  RETURN

;**********CLEAR BANK************************
CLR_BANK
  LFSR FSR0,00H  ;BANK 0
NEXT CLRF POSTINC0
  BTFSS FSR0H,0
  GOTO NEXT
  LFSR FSR0,100H
NEXT1 CLRF POSTINC0  ;BANK1
  BTFSS FSR0H,1
  GOTO NEXT1
  LFSR FSR0,200H
NEXT2 CLRF POSTINC0  ;BANK 2
  BTFSS FSR0H,0
  GOTO NEXT2 
  LFSR FSR0,0F00H 
NEXT3 CLRF POSTINC0  ;BANK 15
  BTFSS FSR0L,7  
  GOTO NEXT3
  RETURN
    END 


#INCLUDE <P18F248.INC>
; 接收数据
;*************LOCAL MACROS*************** 
CONFIGURE_MODE MACRO
  BSF CANCON,REQOP2
  ENDM
NORMAL_MODE  MACRO
  BCF CANCON,REQOP2 
  BCF CANCON,REQOP1
  BCF CANCON,REQOP0  
  BCF CANCON,ABAT
  ENDM

;******************复位矢量中断向量*************
  ORG  000h  
  NOP
  GOTO  MAIN
  ORG  0008h
  
RXB0_INTERRUPT
  BCF  RXB0CON,RXFUL  ;必须清零,否则会溢出到RXB1D0
  BCF  PIR3,RXB0IF 
  MOVFF  RXB0D0,PORTC ;接收到放到PORTC显示
  
  RETFIE

;*****************主程序*************************
MAIN
  CALL CLR_BANK  ;CLEAR ALL BANK 0,1,2,15
  
;**********开始进入传输初始化的设定***************
SETUP
  MOVLB 0FH   ;BANK 15
  MOVLW B'11000000'  ;ENABLE ALL 
  MOVWF INTCON   ;enable gie
  MOVLW B'00000001'  ;ONLY ENABLE RXB0IE
  MOVWF PIE3
  CALL SET_PORT  ;set  port
  CALL RXB0_FILTER0  ;RXB0 FILTER0
  CALL BAUD_RATE  ;250KB/S
  NORMAL_MODE    ;NORMAL MODE 
 
STOP
  NOP
  GOTO STOP 
  
;******************RXB0 FILTER0****************
;RXB0_FILTER0 
;  STANDARD FRAME 
;*********************************************
RXB0_FILTER0
  CONFIGURE_MODE
  BCF  RXB0CON,RXM1 
  BCF  RXB0CON,RXM0 
  ;0,0 FILTER 有效
  ;0,1 ONLY STANDARD FRAME
  ;1,1 RECEIVE ALL
  ;1,0 ONLY EXTERN  FRAME 
  MOVLW B'10101111'
  MOVWF RXF0SIDH;
   MOVLW b'11100000'
  MOVWF RXF0SIDL
  MOVLW B'11111111'  ;识别位XXXXX000111
  MOVWF RXM0SIDH
  MOVLW B'11111111'  ;全部起作用
  MOVWF RXM0SIDL  ;进行屏蔽位设定，全部为11
  RETURN 


;***********SET_PORT******************************
SET_PORT
  
  ;********PORTB********
  ;RB0 OUT
  ;RB1 OUT
  ;RB2 OUT TXCAN
  ;RB3 IN RXCAN
  ;RB4 IN 
  ;RB5 IN
  ;RB6  ICD2
  ;RB7  ICD2
  CLRF LATB
  MOVLW B'00001000'
  MOVWF TRISB 
  ;*******PORTC*********
  ;RC0 OUT  RC0-RC7 ALL OUT
  ;RC1 OUT
  ;RC7 OUT
  CLRF LATC
  MOVLW B'00000000'
  MOVWF TRISC 
  RETURN 
;**************BAUD RATE SET******************   
;  FOSC =4MHZ   
;   NOMINAL BIT TIME = 8 TQ
;  TQ=2*(BAUD RATE +1)/FOSC
;  SYN  =1 TQ,PRO=1TQ,PHE1=3TQ,PHE2=3TQ
;  BAUD RATE= 50KB/S
;  BAUD RATE PRESCALER=00100
;   fosc =4mhz MAX_baud rate=250kb/s
;  If fosc=16Mhz ,the max_band=1Mkb/s
;************************************************
BAUD_RATE      ;50KB/S
  CONFIGURE_MODE 
  MOVLW B'00000100'  ;BAUD RATE SET
  MOVWF BRGCON1
  MOVLW B'10010000'
  MOVWF BRGCON2
  MOVLW B'00000010'
  MOVWF BRGCON3  
  RETURN

;**********CLEAR BANK************************
CLR_BANK
  LFSR FSR0,00H  ;BANK 0
NEXT CLRF POSTINC0
  BTFSS FSR0H,0
  GOTO NEXT
  LFSR FSR0,100H
NEXT1 CLRF POSTINC0  ;BANK1
  BTFSS FSR0H,1
  GOTO NEXT1
  LFSR FSR0,200H
NEXT2 CLRF POSTINC0  ;BANK 2
  BTFSS FSR0H,0
  GOTO NEXT2 
  LFSR FSR0,0F00H 
NEXT3 CLRF POSTINC0  ;BANK 15
  BTFSS FSR0L,7  
  GOTO NEXT3
  RETURN
   
   END