實驗內(nèi)容：

按下圖連接器件：

程序如下所示：

#include reg52.h>
#include intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit SDA=P1^1;
sbit SHIFT = P1^2;
sbit ST = P1^0;
#define NOP _nop_()
uchar led[] = {0x5b,0x3f,0x3f,0x6f};
uchar select[] = {0x0fe,0xfd,0xfb,0xf7};
uchar i=0;
void Init()
{
 SDA = 0;
 SHIFT = 0;
 ST = 0;
}
void delay()
{
uchar jj;
for(jj=0;jj200;jj++);
while(jj--);
}
void display(uchar dat)
{
 uchar ii;
 uchar sdata=dat;
for(ii=0;ii8;ii++)
{
 if(sdata0x80)
SDA=1;
 else
SDA = 0;
 sdata=1;
 SHIFT =0;
 NOP;
 NOP;
 SHIFT = 1;
 NOP;
 NOP;
 }
 ST = 1;
 NOP;
 NOP;
 ST = 0;
}
void main()
{
 Init();
 while(1)
{
 delay();
delay();
 P2 = select[i];
 display(led[i]);
 i=(i+1)%4;
 }
}