嵌入式实验二代码

#include<reg51.h>


unsigned char code LED7Code[] = {0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x67};

void delay(void){
    unsigned char i;
    for(i=0;i<250;i++){

    }

}


main(){
    unsigned int num=0;
    char label_4,label_3,label_2,label_1;
    unsigned char i;

    P2=0xFF;

    while(1){
        for(i=0;i<0xFF;i++){

            label_4=num/1000;
            label_3=(num-label_4*1000)/100;
            label_2=(num-label_4*1000-label_3*100)/10;
            label_1=num%10;

            P2 = 0xFF;
            P0 = LED7Code[label_4];
            P20 = 0;
            delay();

            P2 = 0xFF;
            P0 = LED7Code[label_3];
            P21 = 0;
            delay();

            P2 = 0xFF;
            P0 = LED7Code[label_2];
            P22 = 0;
            delay();

            P2 = 0xFF;
            P0 = LED7Code[label_1];
            P23 = 0;
            delay();
        }
        if(i=0xFF){
            num++;
        }


    }
}