关于中断程序，我想通过该代码使流水灯暂停，但是这个结果出来是

#include<reg52.h>
sbit P32=P3^2;
sbit P33=P3^3;
unsigned char liushui[]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};
unsigned char i,a;
void delay(unsigned char n)
{
unsigned char j;
while(n--)
{
for(j=0;j<113;j++);
}
}
void main()
{
TCON=0x05;
IE=0x85;
P1=0xff;
while(1)
{
if(a==1)
P1=0xff;
if(a==0)
for(i=0;i<8;i++)// _crol_(liushui,1);
{
P1=liushui[i];
delay(1000);
}
}
}
void inter0()interrupt 0
{
EX0=0;
a=0;
EX0=1;
}
void inter1()interrupt 2
{
EX1=0;
a=!a;//a+=1;if(a==2)a=0;while(P33==0);
EX1=1;
}