簡易數(shù)字萬用表設(shè)計(jì)畢業(yè)設(shè)計(jì)-閱讀頁
2025-07-16 00:17本頁面
【正文】 了很多寶貴的資料。單片機(jī)復(fù)位地址 ajmp main 。main被定位在0x0100處main: mov sp,80h 。0808 A/D轉(zhuǎn)換子程序 MOV DPTR,7FFFH MOVX DPTR,A JB ,$ MOVX A,DPTR 。乘以500 clr C mov A,r5 add A,60h 。除以255 mov r1,38h mov r1,00h inc r1 mov r1,00h inc r1 mov r1,00h inc r1 mov r1,0Ah call DIVD4 mov 43h,33h call DIVD4 mov 42h,33h call DIVD4 mov 41h,33h mov r0,40h mov r0,00h inc r0 mov A,41h mov DPTR,SEGMENT7 movc A,A+DPTR orl A,80h mov r0,A inc r0 mov A,42h mov DPTR,SEGMENT7 movc A,A+DPTR mov r0,A inc r0 mov A,43h mov DPTR,SEGMENT7 movc A,A+DPTR mov r0,A retADAT: mov B,A mov A,0B6h clr C 。乘以50000 clr C mov A,r5 subb A,70h 。除以89760 mov r1,38h mov r1,00h inc r1 mov r1,00h inc r1 mov r1,00h inc r1 mov r1,0Ah mov DPTR,SEGMENT7 call DIVD4 mov A,33h movc A,A+DPTR mov 43h,A call DIVD4 mov A,33h movc A,A+DPTR mov 42h,A call DIVD4 mov A,33h movc A,A+DPTR cjne A,3Fh,NOTEQU mov A,00hNOTEQU: mov 41h,A mov 40h,00h RETrdat: mov R2,00h mov R3,A mov R6,03h mov R7,0E8h call MULD2 。除以255 mov r1,38h mov r1,00h inc r1 mov r1,00h inc r1 mov r1,00h inc r1 mov r1,0Ah mov DPTR,SEGMENT7 call DIVD4 。取得10進(jìn)制值 movc A,A+DPTR mov 43h,A call DIVD4 mov A,33h movc A,A+DPTR mov 42h,A call DIVD4 mov A,33h movc A,A+DPTR mov 41h,A call DIVD4 mov A,33h movc A,A+DPTR cjne A,3Fh,NONZERO mov A,00hNONZERO: mov 40h,A retDELAY_5ms: mov R5,01h 。設(shè)置R6初始計(jì)數(shù)值DELAY_5ms2: mov R7,70h 。延時時間為 Time=( ( (R7*2)+2+1 )*R6+2+1 )*R5+1 djnz R6,DELAY_5ms2 。 ret SEGMENT7: DB 3Fh 。寫第一位數(shù)碼管 mov r1,40h mov A,r1 movx DPTR,A setb C mov ,C clr C mov ,C call DELAY_5ms setb C mov ,C inc r1 mov A,r1 。寫第三位數(shù)碼管 movx DPTR,A setb C mov ,C clr C mov ,C call DELAY_5ms setb C mov ,C inc r1 mov A,r1 。雙字節(jié)二進(jìn)制無符號數(shù)乘法。MULD2: MOV A,R3 MOV B,R7 MUL AB MOV R4,B MOV R5,A MOV A,R3 MOV B,R6 MUL AB ADD A,R4 MOV R4,A CLR A ADDC A,B MOV R3,A MOV A,R2 MOV B,R7 MUL AB ADD A,R4 MOV R4,A MOV A,R3 ADDC A,B MOV R3,A CLR A RLC A XCH A,R2 MOV B,R6 MUL AB ADD A,R3 MOV R3,A MOV A,R2 ADDC A,B MOV R2,A ORL A,R3 JZ MULD21 SETB OV RETMULD21: CLR OV RET 。R0存放被除數(shù),除數(shù),商數(shù)的地址。從R0開始的連續(xù)四個字節(jié)為結(jié)果的余數(shù),入口時可以為任意，但在出口時發(fā)生變化。其后的連續(xù)4個字節(jié)在入口時是被除數(shù),出口時是商數(shù)。再其后的連續(xù)四個字節(jié)在入口時是除數(shù),出口時保持不變。用到累加器A,B,PSW,R0~R7。如果除數(shù)為零，則置OV=1標(biāo)志，否則清零。在出口時總是清除
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