cs8-2.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	
#define  S(a,b)  (a-b)*3
uchar code SEG7[10]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
//===============================
void delay(uint k)		
{					
uint i,j;				
for(i=0;i<k;i++){			
for(j=0;j<121;j++)		
{;}}					
}					
//===============================
void main(void)		
{				
uchar out;		
out= S(100,50);		
while(1)					
	{				
	P0= SEG7[out/100];
	P2=0xfb;			
	delay(1);			
	P0= SEG7[ (out%100)/10];
	P2=0xfd;			
	delay(1);			
	P0= SEG7[ out%10];	
	P2=0xfe;			
	delay(1);			
	}				
}