- #include<reg52.h>
- #define uint unsigned int
- #define uchar unsigned char
- sbit D1=P0^7;
- uchar sr;
- uchar jf;
- uchar code table[]={0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,
- 19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,
- 37,38,39,40,41,42,43,44,45,46,47,48,49};
- void light(uchar num);
- void delay(uint z);
- void main()
- {
- //設置計數器
- //選取計數方式1
- TMOD = 0x11;
- //給計數器寫初值
- TH0 = 0;
- TL0 = 0;
- ////////////////////
- //操作單片機
- //開啟CPU中斷
- EA = 1;
- ///////////////////
- //開啟定時器T0位中斷
- ET0 = 1;
- //開啟計數器
- TR0 = 1;
- //操作二極管
- P1=0;
- while(1)
- {
- if(sr<50)
- light(sr);
- else sr=0;
- }
- }
- //子函數
- void light(uchar num)
- {
- uchar tme;
- D1 = 0;
- tme = table[num];
- delay(tme);
- D1 = 1;
- delay(49-tme);
- }
- //中斷函數
- void time () interrupt 1
- {
- //自變量自加
- if (jf<2)
- {
- jf++;
- TH0 =0;
- TL0 = 0;
- }
-
- if (jf==2)
- {
- //寫初值
- jf=0;
-
- TH0 = 254;
- TL0 = 254;
- sr++;
- }
- }
- void delay(uint z)
- {
- uint x,y;
- for(x=10;x>0;x--)
- for(y=z;y>0;y--);
- }
{
jf++;
TH0 =0;
TL0 = 0;
}不是很明白，如果不給定時器重新賦初值的話，定時器還有用嗎
|
