简易数字秒表《项目驱动式单片机应用》.doc

项目驱动式单片机应用简易数字秒表【任务描述】 按下起停键，秒表暂停与计时；按下复位键，秒表复位。【源程序】;端口声明OUTBIT EQU P2OUTSEG EQU P0KEYPORT EQU P3;P3.0 P3.1;变量声明PER equ 30hSEC equ 31hMIN equ 32hLEDBUF EQU 40HBITPOS EQU 3FHKEYVAL EQU 33H; ORG 0 LJMP MAIN ORG 000BH LJMP T0_ISR ORG 0030HMAIN: MOV MIN,#0 MOV SEC,#0 MOV PER,#0 mov TMOD,#01 MOV TH0,#0DCH MOV TL0,#00H MOV IE,#82H SETB TR0LP: LCALL KSCAN LCALL KPROC LCALL TOLEDBUF LCALL DISP6 SJMP LPt0_isr: mov th0,#0DCH ;11.0592M 10MS mov tl0,#00H push a push psw inc per mov a,per cjne a,#100,retx mov per,#0 inc sec mov a,sec cjne a,#60,retx mov sec ,#0 inc min mov a,min cjne a,#60,retx mov min,#0 retx: pop psw pop a retiTOLEDBUF: MOV A,PER MOV B,#10 DIV AB MOV 41H,A MOV 40H,B MOV A,SEC MOV B,#10 DIV AB MOV 43H,A MOV 42H,B MOV A,MIN MOV B,#10 DIV AB MOV 45H,A MOV 44H,B RET;6位数码管动态扫描 入口参数：40h-45h 对应数码管从右往左DISP6: MOV DPTR,#SEG7 MOV R2,#6;循环计数 MOV BITPOS,#7FH MOV R0,#LEDBUFDISPLP: MOV OUTBIT,BITPOS MOV A,R0 MOVC A,A+DPTR MOV OUTSEG,A LCALL DELAY;1MS INC R0 MOV A,BITPOS RR A MOV BITPOS,A DJNZ R2,DISPLP RETSEG7: DB 0C0H,0F9H,0A4H,0B0H,99H,92H ;字符编码（段选信号）0-9 DB 82H,0F8H,80H,90H,00,00,00,00,00,00 DB 40H,79H,24H,30H,19H,12H,02H,78H ;显示小数点（调整位）的字符编码0-9 DB 00H,10H,00,00,00,00,00,00DELAY: MOV R7,#2DD1: MOV R6,#250 DJNZ R6,$ DJNZ R7,DD1 RET;按键扫描 p3.0 p3.1 返回值 KEYVAL 01H 02HKSCAN: MOV A,KEYPORT CPL A ANL A,#03H JZ RETK ;无键返回 LCALL DISP6 LCALL DISP6 MOV A,KEYPORT CPL A ANL A,#03H JZ RETK ;无键返回 MOV KEYVAL,AKLP: LCALL DISP6 MOV A,KEYPORT CPL A ANL A,#03H JNZ KLPRETK: RETKPROC: MOV A,KEYVAL MOV KEYVAL,#0 JB ACC.0,KEYQT JB ACC.1,KEYRST SJMP RETKPKEYQT: MOV 40H,#3 CPL TR0 SJMP RETKPKEYRST: MOV PER,#0 MOV MIN