请教过零同步

请教各位高手，能帮我把这个C程序的过零检测这段程序换成汇编吗，或者给点思路都行，先谢谢了！






//七色渐变（过零检测）
//晶振24MHZ
#include <reg52.h>
#include <stdio.h>
typedef unsigned char uchar;

sbit blue=P1^7;
sbit green=P1^6;
sbit red=P1^5;
sbit int0_tag=P3^2;
uchar zero_tag;
unsigned int time;
void delay_time1(unsigned int m)
{

uchar j;
EA=0;
while(m--)
{
for(j=0; j<10; j++){;}
}
EA=1;
}
void delay_time(unsigned int m)
{
EA=0;
while(m--)
{
;
}
EA=1;
}

void wait(uchar mm)
{
uchar tt;
for(tt=0;tt<mm;tt++)
{
while(!zero_tag);
zero_tag=0;
delay_time1(400);
}
}
//通过对交流过零点检测，实现七色渐变
void initialize()
{
IT0=1;
EX0=1;
EA=1;
}

void main()
{

unsigned int t,w=500;
initialize();
red=green=blue=1;
do
{

for(t=1;t<w;t++) // 由白色渐变红色
{
while(!zero_tag);
zero_tag=0;
red=1;
green=1;
blue=1;
delay_time1(w-t);

red=1;
green=0;
blue=0;
delay_time1(t);
}


for(t=1;t<w;t++) //由红色渐变黄色
{
while(!zero_tag);
zero_tag=0;
red=1;
green=0;
blue=0;
delay_time1(w-t);
red=1;
green=1;
blue=0;
delay_time1(t);
}


for(t=1;t<w;t++) //由黄色渐变绿色
{
while(!zero_tag);
zero_tag=0;
red=1;
green=1;
blue=0;
delay_time1(w-t);
green=1;
red=0;
blue=0;
delay_time1(t);
}


for(t=1;t<w;t++) //由绿色渐变青色
{ while(!zero_tag);
zero_tag=0;
blue=0;
green=1;
red=0;
delay_time1(w-t);
green=1;
blue=1;
red=0;
delay_time1(t);
}


for(t=1;t<w;t++) //由青色渐变兰色
{ while(!zero_tag);
zero_tag=0;
green=1;
blue=1;
red=0;
delay_time1(w-t);
blue=1;
red=0;
green=0;
delay_time1(t);
}



for(t=1;t<w;t++) //由兰色渐变紫色
{
while(!zero_tag);
zero_tag=0;
red=0;
blue=1;
green=0;
delay_time1(w-t);
blue=1;
red=1;
green=0;
delay_time1(t);
}



for(t=1;t<w;t++) //由紫色渐变白色
{ while(!zero_tag);
zero_tag=0;
red=1;
green=0;
blue=1;
delay_time1(w-t);
red=1;
blue=1;
green=1;
delay_time1(t);
}



} while(1);
}

void int0_int(void) interrupt 0
{
delay_time(4);
if(int0_tag==0)
{
zero_tag=1;
time++;
}
else{;}
}