数字电压表的设计（基于89c51的单片机）

#include <AT89X52.H> #include "intrins.h" //调用_nop_();延时函数用 unsigned char code dispbitcode[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; unsigned char dispbuf[4]; unsigned char getdata; unsigned int temp; sbit ST=P3^0; sbit OE=P3^1; sbit EOC=P3^2; sbit CLK=P3^3; sbit ALE=P3^7; sbit P34=P3^4; sbit P35=P3^5; sbit P36=P3^6; sbit P20=P2^0; sbit P21=P2^1; sbit P22=P2^2; sbit P23=P2^3; sbit P17=P1^7; void TimeInitial(); void Delay(unsigned int i); void TimeInitial() { TMOD=0x01; TH0=(65536-200)/256; TL0=(65536-200)%256; EA=1; ET0=1; TR0=1; } void Delay(unsigned int i) { unsigned int j; for(;i>0;i--) { for(j=0;j<100;j++) {;} } } void Display() { P1=dispbitcode[dispbuf[3]]; P20=0; P21=1; P22=1; P23=1; Delay(10);//避免闪烁 P1=0x00; //关闭一下，否则显示不全 P1=dispbitcode[dispbuf[2]]; P17=1; P20=1; P21=0; P22=1; P23=1; Delay(10); P1=0x00; P1=dispbitcode[dispbuf[1]]; P20=1; P21=1; P22=0; P23=1; Delay(10); P1=0x00; P1=dispbitcode[dispbuf[0]]; P20=1; P21=1; P22=1; P23=0; Delay(10); P1=0x00; } void main() { TimeInitial(); while(1) { P34=0; //地址通道 P35=0; P36=0; ALE=1; _nop_(); _nop_(); ALE=0; ST=1; _nop_(); _nop_(); ST=0; _nop_(); _nop_(); _nop_(); _nop_(); while(EOC==0); OE=1; getdata=P0; OE=0; temp=getdata*1.0/255*500; dispbuf[0]=temp%10; dispbuf[1]=temp/10%10; dispbuf[2]=temp/100%10; dispbuf[3]=temp/1000; Display(); } } void t0(void) interrupt 1 using 0 { TH0=(65536-200)/256; TL0=(65536-200)%256; CLK=~CLK; }