【正文】 DELAY10 JB ,MAIN2_3 JNB ,$ MOV A,A1 CJNE A,50,MAIN2_2_1 AJMP MAIN2_2_3MAIN2_2_1: JC MAIN2_2_2 CLR C MOV B,1 SUBB A,B AJMP MAIN2_2_3MAIN2_2_2: MOV A,50MAIN2_2_3: MOV A1,A。MAIN2_3: ACALL TRAST1 MOV 32H,A MOV 31H,B RET。顯示子程序。DISPLAY: MOV A,A1 。將待顯示的數(shù)存在70H到75H中 MOV B,100 DIV AB 。顯示子程序 MOV 73H,A 。百位在A MOV A,B 。 MOV B,10 DIV AB MOV 72H,A 。十位在B MOV 71H,B 。個位在C MOV A,51H 。將的十六進制數(shù)轉(zhuǎn)換成十進制 MOV B,100 DIV AB 。顯示子程序 MOV 76H,A 。百位在A MOV A,B MOV B,10 DIV AB MOV 75H,A 。十位在B MOV 74H,B 。個位在CDISP1: MOV R1,70H 。指向顯示數(shù)據(jù)首址 MOV R5,0FEH 。掃描控制字初值PLAY: MOV P1,0FFH MOV A,R5 。掃描字放入A MOV P2,A 。從P2口輸出 MOV A,@R1 。取顯示數(shù)據(jù)到A MOV DPTR,TAB 。取段碼表地址 MOVC A,@A+DPTR 。查顯示數(shù)據(jù)對應段碼 MOV P1,A 。段碼放入P1口 MOV A,R5 LCALL D1MS 。顯示1MS INC R1 。指向下一地址 MOV A,R5 。掃描控制字放入A JNB ,ENDOUT 。=0時一次顯示結(jié)束 RL A 。A中數(shù)據(jù)循環(huán)左移 MOV R5,A 。放回R5內(nèi) AJMP PLAY 。跳回PLAY循環(huán)ENDOUT: MOV P1,0FFH 。一次顯示結(jié)束，P2口復位 MOV P2,0FFH 。P3口復位 RET 。子程序返回TAB: DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H,0FFH。共陽段碼表 0 1 2 3 4 5 6 7 8 9不亮“”。延時子程序。D1MS: MOV R6,14H 。1MS延時程序，LED顯示程序用DL1: MOV R7,19HDL2: DJNZ R7,DL2 DJNZ R6,DL1 RETDELAY10: MOV R6,20 。10MS延時D3: MOV R5,255 DJNZ R5,$ DJNZ R6,D3 RETDELAY125: MOV R6,255 。125MS延時D1: MOV R5,255 DJNZ R5,$ DJNZ R6,D1 RETDELAY1S: MOV R7,8 。1S延時D2: LCALL DELAY125 DJNZ R7,D2 RET 。PID算法子程序。PID: MOV R5,31H MOV R4,32H MOV R3,2AH MOV R2,00H ACALL CPL1 ACALL DSUM MOV 39H,R7 MOV 3AH,R6 MOV R5,35H MOV R4,36H MOV R0,4AH ACALL MULT1 MOV R5,39H MOV R4,3AH MOV R3,3BH MOV R2,3CH ACALL CPL1 ACALL DSUM MOV R5,33H MOV R4,34H MOV R0,46H ACALL MULT1 MOV R5,49H MOV R4,48H MOV R3,4DH MOV R2,4CH ACALL DSUM MOV 4AH,R7 MOV 4BH,R6 MOV R3,4AH MOV R2,4BH MOV R5,2FH MOV R4,30H ACALL DSUM MOV 2FH,R7 MOV 30H,R6 MOV 3DH,3BH MOV 3EH,3CH MOV 3BH,39H MOV 3CH,3AH RET。雙字節(jié)加法程序。 R5R4+R3R2=R7R6 。DSUM: MOV A,R4 ADD A,R2 MOV R6,A MOV A,R5 ADDC A,R3 MOV R7,A RET。雙子節(jié)求補程序?qū)3R2求補。CPL1: MOV A,R2 CPL A ADD A,01H MOV R2,A MOV A,R3 CPL A ADDC A,00H MOV R3,A RET。雙字節(jié)帶符號乘法子程序 。MULT1: MOV A,R7 RLC A MOV ,C JNC POS1 MOV A,R6 CPL A ADD A,01H MOV R6,A MOV A,R7