#include<reg52.h>
unsigned char t=20;
unsigned char table[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
sbit P0_0=P0^0;
void int0();
void main()
{
int0();
while(1);
}
void int0()
{
TMOD=1;
EA=1;
ET0=1;
TR0=1;
TL0=(65536-50000)%256;
TH0=(65536-50000)/256;
}
void int0_0() interrupt 1
{
static unsigned char i=7;
TL0=(65536-50000)%256;
TH0=(65536-50000)/256;
while(!t--)
{
P1=table[i--];
if(-1==i)
{
i=7;
}
P0_0=!P0_0;
t=20;
}
}
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