multibyte-receive.txt

PIC单片机16f628A串口发送接收程序．汇编语言编写

STATUS 	EQU 03H  ; 定义状态寄存器地址
PORTA   EQU 05H 
PORTB 	EQU 06H  ;端口B的数据寄存器地址
TRISA   EQU 5H
TRISB 	EQU 6H   ;定义端口B的方向控制寄存器地址
CMCON   EQU 1FH
SPBRG 	EQU 19H
TXSTA 	EQU 18H
RCSTA 	EQU 18H
TXREG 	EQU 19H
RCREG 	EQU 1AH
PIR1  	EQU 0CH
dataL 	EQU 20H
DATA1   EQU 21H
PIE1    EQU 0CH
INTCON  EQU 0BH
RECEIVE_DATA  EQU  23H
FSR     EQU 04H
INDF    EQU 00H
COUNT   EQU 30H
;----------------------  
RP0     EQU 5  ;定义状态寄存器中的RAM页选位RP0
RP1     EQU 6
RCIF    EQU 5
TRMT    EQU 1
KEY1 	EQU 6
KEY2 	EQU 7

RCIE    EQU 5
PEIE    EQU 6
GIE     EQU 7
TXIE    EQU 4
TXIF    EQU 4
IRP     EQU 7
    	ORG    0x000            ; Program starts at 0x000 
; ---------------- 
; INITIALIZE PORTS
; ---------------- 
;
	GOTO      MAIN                                   ;跳转到初始化程序
        ORG       0X0004                                 ;中断矢量
        
        BCF   STATUS,RP0
        BTFSS  PIR1,RCIF
        GOTO  TX_INT
   RC_INT
        NOP
        MOVF  RCREG,W
        MOVWF INDF
        INCF  FSR
        INCF  COUNT
        NOP
        GOTO INT_END
   TX_INT
        BSF  STATUS,RP0
        BTFSS  PIE1,TXIE
        GOTO  INT_END
        BCF   STATUS,RP0
        BTFSS PIR1,TXIF
        GOTO  INT_END
        
        MOVLW  0FFH
        MOVWF  TXREG
 
        bsf STATUS,RP0	    ; RAM PAGE 1
WAIT_SEND  btfss TXSTA,TRMT    ; (1) transmission is complete if hi
        goto WAIT_SEND
        BSF   STATUS,RP0     ; close  send int
         BCF     PIE1,TXIE   
        
        bcf STATUS,RP0      ; RAM PAGE 0
       
INT_END
    RETFIE                                            
		
MAIN	movlw 	7
	movwf 	CMCON			; CMCON=7 set comperators off 
  INITA 
	BCF  STATUS,RP0 
	BCF  STATUS,RP1

        bsf 	STATUS,RP0      	; RAM PAGE 1
        movlw 	b'11110010'	; RB7-RB4 and RB1(RX)=input, others output 
        movwf 	TRISB	

        

; ------------------------------------
; SET BAUD RATE TO COMMUNICATE WITH PC
; ------------------------------------
; Boot Baud Rate = 9600, No Parity, 1 Stop Bit
;       BSF   STATUS,RP0
        movlw 	0x19          ; 0x19=9600 bps (0x0C=19200 bps)
        movwf 	SPBRG
        movlw 	b'00100100'   ; brgh = high (2)
        movwf 	TXSTA         ; enable Async Transmission, set brgh
        
        
        BSF  PIE1,RCIE   ; open receive  int  
       ; BCF  PIE1,TXIE   ; close  send int
        
        BCF   STATUS,RP0
        MOVLW  B'10010000'
        movwf 	RCSTA       
        BCF    PIR1,RCIF
             
        CLRF  INTCON
	BSF     INTCON,GIE                             ;使能全局中断使能位
	BSF     INTCON,PEIE                            ;使能外设中断使能位
        BSF    STATUS,RP0

         BCF   STATUS,RP0
         
         
         BCF  STATUS,IRP
         MOVLW  0A0H
         MOVWF  FSR
         CLRF   COUNT
   
       LOOP
            NOP
            MOVLW  05H
            XORWF  COUNT,W
            BTFSS  STATUS,2
            GOTO   LOOP_END
            GOTO   SEND_BACK
        LOOP_END    
            NOP
            GOTO  LOOP
SEND_BACK
        MOVLW  0A0H
        MOVWF  FSR
    SEND_LOOP
        MOVF   INDF,W
        CALL SEND
        INCF  FSR
        DECFSZ  COUNT
        GOTO   SEND_LOOP
        GOTO  LOOP_END
  		

SEND
       movwf TXREG         ; send data in W 

       bsf STATUS,RP0	    ; RAM PAGE 1
WtHere  btfss TXSTA,TRMT    ; (1) transmission is complete if hi
        goto WtHere

        bcf STATUS,RP0      ; RAM PAGE 0
        return


DLY10MS  MOVLW  05H             ;不是10MS
         MOVWF  63H             ;(254*3+2+3+2)*4+2=3078
DLY10MS1 MOVLW  0FFH
         MOVWF  64H
DLY10MS2 DECFSZ 64H
         GOTO   DLY10MS2
         DECFSZ 63H
         GOTO   DLY10MS1
         RETLW   00H  

END