//實(shí)例9：用P0口、P1 口分別顯示加法和減法運(yùn)算結(jié)果
#include<reg51.h>
void main(void)   
{  
  unsigned char m,n;
  m=43;     //即十進(jìn)制數(shù)2x16+11=43
  n=60;     //即十進(jìn)制數(shù)3x16+12=60
  P1=m+n;  //P1=103=0110 0111B,結(jié)果P1.3、P1.4、P1.7 口的燈被點(diǎn)亮
  P0=n-m;  //P0=17=0001 0001B,結(jié)果P0.0、P0.4的燈被熄滅
 }