AT24C02做的I2C通信仿真问题，高手进!!

预想的是P3.0口输出低电平，可是仿真结果是P3.7输出了高电平，高手解答下怎么回事，不盛感激~~！！！

#include<reg52.h>
#define uchar unsigned char
sbit scl=P2^0;
sbit sda=P2^1;
void delay(int z)
{
int x,y;
for(x=z;x>0;x--)
for(y=50;y>0;y--);
}
void start()
{
sda=1;
delay(1);
scl=1;
delay(1);
sda=0;
delay(1);
scl=0;
delay(1);
}
void stop()
{
sda=0;
delay(1);
scl=1;
delay(1);
sda=1;
delay(1);
scl=0;
delay(1);
}
void response()
{
uchar i;
scl=1;
delay(1);
while((sda==1)&&(i<255))
i++;
scl=0;
delay(1);
}
void write(uchar dat)
{
uchar i,temp;
temp=dat;
scl=0;
delay(1);
for(i=0;i<8;i++)
{
temp=temp<<1;
sda=CY;
delay(1);
scl=1;
delay(1);
scl=0;
delay(1);
}
}
uchar read()
{
uchar i,j,k;
scl=0;
delay(1);
sda=1;
delay(1);
for(i=0;i<8;i++)
{
scl=1;
delay(1);
j=sda;
delay(1);
k=(k<<1)|j;
scl=0;
delay(1);
}
return k;
}
void main()
{
sda=1;
delay(1);
scl=1;
delay(1);
start();
write(0xa0);
response();
write(1);
response();
write(0xfe);
response();
stop();
delay(100);
start();
write(0xa0);
response();
write(1);
response();
start();
write(0xa1);
P3=read();
stop();
while(1);
}