cs14-1.c

《手把手教你学单片机的C程序设计》及实验程序

#include <REG51.H>	
#define uchar unsigned char			
#define uint unsigned int		
/****************************************************************/
void delay(uint k)			
{						
uint i,j;					
for(i=0;i<k;i++){			
for(j=0;j<121;j++)				
{;}}						
}				
/***********************************************/
void main(void)		
{				
 uchar a,b;			
 uchar *p;			
 p=&b;				
 a=0x7f;			
 *p=0x7f;
 while(1)			
{
 P0=b;	
 P2=0xfe;
 delay(1);			
 P3=a;
 P2=0xf7;
 delay(1);				
}			
}