微机课设--汇编语言在51单片机上写一个四位十进制加法器

代码如下

KEYVAL EQU 30HKEYTM EQU 31HKEYSCAN EQU 32HDAT  EQU 33HSCANLED EQU 37HS_DAT EQU 38HD_DAT EQU 39HR_DATL EQU 3AHR_DATH EQU 3BH
CALFLAG EQU 3CHFLAG BIT 00HORG 0000HLJMP MAINORG 000BHLJMP T0ISRORG 0030HMAIN:MOV SP,#5FHMOV TMOD,#01HMOV TH0,#0D8HMOV TL0,#0F0HMOV KEYVAL,#0MOV P2,#00HMOV SCANLED,#0MOV 33H,#0HMOV 34H,#0HMOV 35H,#0HMOV 36H,#0HMOV S_DAT,#0MOV D_DAT,#0CLR FLAGSETB EASETB ET0SETB TR0LOOP:LCALL KEYSELMOV A,KEYVALCJNE A,#0FFH,LOOP1SJMP LOOPLOOP1:CJNE A,#11,LOOP2 ;“=”MOV A,33HMOV B,#10MUL ABADD A,34HMOV D_DAT,ALCALL DEALDATLCALL HB2MOV A,R5ANL A,#0FHMOV 34H,AMOV A,R5SWAP AANL A,#0FHMOV 33H,AMOV A,R4ANL A,#0FHMOV 36H,AMOV A,R4SWAP AANL A,#0FHMOV 35H,ASJMP LOOPLOOP2:CJNE A,#15,LOOP3 ;“+”LCALL GETDATSJMP LOOPLOOP3:CJNE A,#14,LOOP4 ;“-”MOV CALFLAG,#1LCALL GETDATSJMP LOOPLOOP4:CJNE A,#13,LOOP5 ;“*”MOV CALFLAG,#2LCALL GETDATSJMP LOOPLOOP5:CJNE A,#12,LOOP6 ;"/"MOV CALFLAG,#3LCALL GETDATSJMP LOOPLOOP6:CJNE A,#10,LOOP7  ;数字键LOOP7:JC LOOP8LJMP LOOPLOOP8:MOV 33H,34HMOV 34H,KEYVALLJMP LOOP;------------------HB2:MOV R6,R_DATHMOV R7,R_DATLCLR  A   ;BCD码初始化MOV  R3,AMOV  R4,AMOV  R5,AMOV  R2,#10H   ;转换双字节十六进制整数HB3:MOV  A,R7   ;从高端移出待转换数的一位到 CY 中RLC  AMOV  R7,AMOV  A,R6RLC  AMOV  R6,AMOV  A,R5   ;BCD码带进位自身相加，相当于乘2ADDC  A,R5DA  A   ;十进制调整MOV  R5,AMOV  A,R4ADDC  A,R4DA  AMOV  R4,AMOV  A,R3ADDC  A,R3MOV  R3,A   ;双字节十六进制数的万位数不超过6，不用调整DJNZ  R2,HB3   ;处理完16bitRET;------------------GETDAT:MOV A,33HMOV B,#10MUL ABADD A,34HMOV S_DAT,AMOV 33H,#0MOV 34H,#0MOV 35H,#0MOV 36H,#0RET;------------------DEALDAT:MOV A,CALFLAGJNZ DEAL01DEAL00:    ;+MOV A,S_DATADD A,D_DATMOV R_DATL,ACLR AADDC A,#0MOV R_DATH,ARETDEAL01:    ;=DEC AJNZ DEAL02CLR CMOV A,S_DATSUBB A,D_DATMOV R_DATL,ASUBB A,#0MOV R_DATH,ARETDEAL02:    ;*DEC AJNZ DEAL03MOV A,S_DATMOV B,D_DATMUL ABMOV R_DATL,AMOV R_DATH,BRETDEAL03:    ;/MOV A,S_DATMOV B,D_DATDIV ABMOV R_DATL,AMOV R_DATH,#0RET;------------------KEYSEL: MOV KEYVAL,#0MOV KEYSCAN,#0EFHLCALL GETKEYMOV A,KEYTMJZ KEYS1MOV KEYVAL,ASJMP KEYRTNKEYS1: MOV KEYSCAN,#0DFHLCALL GETKEYMOV A,KEYTMJZ KEYS2CLR CADD A,#4MOV KEYVAL,ASJMP KEYRTNKEYS2: MOV KEYSCAN,#0BFHLCALL GETKEYMOV A,KEYTMJZ KEYS3CLR CADD A,#8MOV KEYVAL,ASJMP KEYRTNKEYS3: MOV KEYSCAN,#7FHLCALL GETKEYMOV A,KEYTMJZ KEYRTNCLR CADD A,#12MOV KEYVAL,AKEYRTN: LCALL CHGKEYRET;--------------------GETKEY: MOV KEYTM,#0MOV A,KEYSCANMOV P3,ANOPMOV A,P3ANL A,#0FHXRL A,#0FHJZ NOKEYMOV R2,#10LCALL DELAYMOV A,P3ANL A,#0FHXRL A,#0FHJZ NOKEYMOV A,P3ANL A,#0FHMOV R7,ASF:MOV A,P3ANL A,#0FHXRL A,#0FHJNZ SFMOV A,R7CJNE A,#0EH,NK1MOV KEYTM,#1SJMP NOKEYNK1:CJNE A,#0DH,NK2MOV KEYTM,#2SJMP NOKEYNK2:CJNE A,#0BH,NK3MOV KEYTM,#3SJMP NOKEYNK3:CJNE A,#07H,NOKEYMOV KEYTM,#4NOKEY: RET;--------------------DELAY:MOV R3,#50DELAY1:MOV R4,#100DJNZ R4,$DJNZ R3,DELAY1DJNZ R2,DELAYRET;--------------------T0ISR:PUSH ACCCLR TR0MOV TH0,#0D8HMOV TL0,#0F0HSETB TR0MOV DPTR,#LEDTABT000:      ;数字显示MOV R0,#DATMOV A,SCANLEDADD A,R0MOV R0,AMOV A,SCANLEDJNZ T001MOV P2,#01HSJMP T0DIST001:DEC AJNZ T002MOV P2,#02HSJMP T0DIST002:DEC AJNZ T003MOV P2,#04HSJMP T0DIST003:MOV P2,#08HT0DIS:MOV A,@R0MOVC A,@A+DPTR;  CPL AMOV P0,AINC SCANLEDMOV A,SCANLEDANL A,#03HMOV SCANLED,APOP ACCRETI;--------------------CHGKEY:MOV A,KEYVALJZ KV16DEC AJNZ KV01MOV KEYVAL,#7RETKV01:DEC AJNZ KV02MOV KEYVAL,#4RETKV02:DEC AJNZ KV03MOV KEYVAL,#1RETKV03:DEC AJNZ KV04MOV KEYVAL,#10RETKV04:DEC AJNZ KV05MOV KEYVAL,#8RETKV05:DEC AJNZ KV06MOV KEYVAL,#5RETKV06:DEC AJNZ KV07MOV KEYVAL,#2RETKV07:DEC AJNZ KV08MOV KEYVAL,#0RETKV08:DEC AJNZ KV09MOV KEYVAL,#9RETKV09:DEC AJNZ KV10MOV KEYVAL,#6RETKV10:DEC AJNZ KV11MOV KEYVAL,#3RETKV11:DEC AJNZ KV12MOV KEYVAL,#11 ;=RETKV12:DEC AJNZ KV13MOV KEYVAL,#12 ;/RETKV13:DEC AJNZ KV14MOV KEYVAL,#13 ;*RETKV14:DEC AJNZ KV15MOV KEYVAL,#14 ;-RETKV15:DEC AJNZ KV16MOV KEYVAL,#15 ;+RETKV16:MOV KEYVAL,#0FFHRET;--------------------LEDTAB:DB 0C0H ;"0" 00HDB 0F9H ;"1" 01HDB 0A4H ;"2" 02HDB 0B0H ;"3" 03HDB 99H ;"4" 04HDB 92H ;"5" 05HDB 82H ;"6" 06HDB 0F8H ;"7" 07HDB 80H ;"8" 08HDB 90H ;"9" 09HDB 88H ;"A" 0AHDB 83H ;"B" 0BHDB 0C6H ;"C" 0CHDB 0A1H ;"D" 0DHDB 86H ;"E" 0EHDB 8EH ;"F" 0FHDB 0FFH ;" " 10H;--------------------END