595soft.txt

两片74HC595级联实现8位7段LED动态显示的驱动测试程序

/*该程序为两片74HC595级联实现8位7段LED动态显示的驱动测试程序
   在8个7段LED上显示"01234567"*/

#include<reg51.h>
#define uchar unsigned char
uchar bdata OutByte;         /*定义待输出字节变量*/
sbit Bit_Out=OutByte^7;         /*定义输出字节的最高位，即输出位*/
sbit     Bout=P2^0;             /*位输出引脚*/
sbit     Sclk=P2^1;             /*位同步脉冲输出*/
sbit    SLclk=P2^2;             /*锁存脉冲输出*/
uchar code Segment[]={
     0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,         /*共阴7段LED段码表*/
     0x7c,0x39,0x5e,0x79,0x71,0x76,0x73,0x3e,0x00};


void OneLed_Out(uchar i,uchar Location)   /*输出点亮一个7段LED显示器*/
{
     uchar j;

     OutByte=Location;             /*先输出位码*/
     for(j=1;j<=8;j++)
     {
         Bout=Bit_Out;
         Sclk=0;Sclk=1;Sclk=0;     /*位同步脉冲输出*/
         OutByte=OutByte<<1;
     }

     OutByte=Segment[i];         /*再输出段码*/
     for(j=1;j<=8;j++)
     {
         Bout=Bit_Out;
         Sclk=0;Sclk=1;Sclk=0;     /*位同步脉冲输出*/
         OutByte=OutByte<<1;
     }

     SLclk=0;SLclk=1;SLclk=0;     /*一个锁存脉冲输出*/
}

void main()
{
     uchar i=0;
     uchar Location=1;                 /*定义位码*/

     while(1)
     {
         OneLed_Out(i,Location);
         i=i+1;
         Location=Location<<1;

         if(i==8)                 /*8次一轮*/
         {
             i=0;
             Location=1;
         }
     }
}