LED Left Shift Pattern

Refer 'LED Basic Circuit' in 'Embedded Systems Circuits' Label


#include<reg51.h>
#include<intrins.h>
void ms_delay(unsigned int a)
{
unsigned char b=255;
for(;a-->0;)
for(;b-->0;)
_nop_();
}
void main()

{
 unsigned char i,a,b;
 while(1)
 {
  a=0xfe;
  b=0x03;
  for(i=0;i<8;i++)
  {
    P1=a;
   a=a&b;
   a=~a; 
   b=b<<1; 
   ms_delay(500);
  }  
 }
}