modem2.asm

MODEM芯片的应用

                     
            STHR  EQU 0CFA0H
            SIER  EQU 0CFA1H
            SLCR  EQU 0CFA3H
            SLSR  EQU 0CFA5H
            SLSB  EQU 0CFA0H
            SMSB  EQU 0CFA1H
               
            RRHR  EQU 0CFA8H
            RIER  EQU 0CFA9H
            RLCR  EQU 0CFABH
            RLSR  EQU 0CFADH
            RLSB  EQU 0CFA8H
            RMSB  EQU 0CFA9H
            
            CS244 EQU 0CFB0H
                           
            CSEG  AT 0000H
            LJMP  START
                   
            CSEG  AT 4100H
                   
START:      NOP
INIT_S:     MOV   DPTR, #SLCR            ;modem1初始化
            MOV   A, #80H
            MOVX  @DPTR, A
            MOV   DPTR, #SLSB
            MOV   A, #80H
            MOVX  @DPTR, A
            MOV   DPTR, #SMSB
            MOV   A, #01H
            MOVX  @DPTR, A               ;设置波特率为300
            MOV   DPTR, #SLCR
            MOV   A, #1BH
            MOVX  @DPTR, A               ;8个数据位,1个停止位,偶校验
 ;           MOV   DPTR, #SIER
 ;           MOV   A, #01H
 ;           MOVX  @DPTR, A
            MOV   DPTR, #SLSR
            MOVX  A, @DPTR
            MOV   DPTR, #STHR
            MOVX  A, @DPTR
            
INIT_R:     MOV   DPTR, #RLCR           ;modem2初始化
            MOV   A, #80H
            MOVX  @DPTR, A
            MOV   DPTR, #RLSB
            MOV   A, #80H
            MOVX  @DPTR, A
            MOV   DPTR, #RMSB
            MOV   A, #01H
            MOVX  @DPTR, A             ;设置波特率为300
            MOV   DPTR, #RLCR
            MOV   A, #1BH
            MOVX  @DPTR, A             ;8个数据位,1个停止位,偶校验
   ;         MOV   DPTR, #RIER
   ;         MOV   A, #01H
   ;         MOVX  @DPTR, A 
            MOV   DPTR, #RLSR
            MOVX  A, @DPTR
            MOV   DPTR, #RRHR
            MOVX  A, @DPTR
            
S_DATA:     MOV   DPTR, #SLSR         ;modem1发送
            MOVX  A, @DPTR
            JNB   ACC.5, S_DATA
            MOV   DPTR, #CS244        ;读开关状态
            MOVX  A, @DPTR
            MOV   DPTR, #STHR
            MOVX  @DPTR, A

            
R_DATA:     MOV   DPTR, #RLSR         ;modem2接收
            MOVX  A, @DPTR
            JNB   ACC.0, R_DATA
            MOV   DPTR, #RRHR
            MOVX  A, @DPTR
            MOV   R0, A
            
DISP:       MOV   DPTR,#0CFE9H     ;
            MOV   A,#08H
            MOVX  @DPTR,A

            MOV   DPTR,#0CFE9H     ;写显示RAM命令字
            MOV   A,#90H
            MOVX  @DPTR,A

            MOV  	A, R0           ;转换结果
            ANL		A,#0F0H
            SWAP    A
            ACALL 	TABLE            ;转换为显码
        
            MOV  	DPTR,#0CFE8H     ;8279数据口地址
            MOVX 	@DPTR,A          ;送显码输出
        
            MOV  	A, R0           ;转换结果
            ANL		A,#0FH
            ACALL 	TABLE            ;转换为显码
        
            MOV  	DPTR,#0CFE8H     ;8279数据口地址
            MOVX 	@DPTR,A          ;送显码输出
		    CALL	DELAY
		
		    LJMP	S_DATA	

DELAY:      MOV  R6,#255 		         ;延时
DEL2:       MOV  R5,#4
DEL3:       NOP
            NOP
            DJNZ R5,DEL3
            DJNZ R6,DEL2	
            RET
        
TABLE:      INC  	A
            MOVC 	A,@A+PC
            RET
DB          3FH,06H,5BH,4FH,66H,6DH,7DH,07H
DB          7FH,6FH,77H,7CH,39H,5EH,79H,71H
            

            
            END