//chuong trinh dem xung ngoai dung ngat hien thi tren 2 led 7 doan

//chan thuc hien ngat ngoai RB0/int

//portC noi voi cac doan a,b,c..h

//RD0,RD1 lam nhiem vu quet led

#include"16f877a.h"

#include"def_877a.h"

#use delay(clock=4000000)

int bien_dem,chuc,don_vi,chuc_7doan,don_vi_7doan;

//khai bao ngat ngoai

#int_ext

void ngat_ngoai()

{

bien_dem++;

if (bien_dem>=99) bien_dem=0;

}

//dinh nghia ma 7 doan

const int ma_7doan[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};

//chuong trinh con hien thi

void hien_thi()

{

portc=chuc_7doan;

rd0=0;

delay_ms(50);

rd0=1;

portc=don_vi_7doan;

rd1=0;

delay_ms(50);

rd1=1;

}

//chuong trinh chinh

void main()

{

//dinh nghia cac dau vao ra

trisc=0;   

trisd0=0; 

trisd1=0;  

trisb0=1;  

bien_dem=0;

//khai bao cho phep ngat

enable_interrupts(int_ext);

enable_interrupts(global);

ext_int_edge(h_to_l);      

while (true)

{

chuc=bien_dem/10;          

don_vi=bien_dem%10;       

chuc_7doan=ma_7doan[chuc];   

don_vi_7doan=ma_7doan[don_vi];

hien_thi();

}

}