#include<stc90.h>
void delay(unsigned int s){
    while(s--);
}
void main(void){
unsigned char a;
a=0xFE;
 while(1){
 P0=a;
 delay(60000);
 a=a << 1;
 a=a|0x01;
 if(a==0xFF) a=0xFE;
 }

}

頂