键盘输入字母液晶显示程序不亮

也就是，用矩阵键盘输入字母，然后显示到液晶上
#include
#define uchar unsigned char
#define uint unsigned int
***it du=P2^6;
***it we=P2^7;
***it en=P3^4;
***it rs=P3^5;
***it rw=P3^6;
uchar code tab[]="ABCDEFGHIJKLMNOP";
uchar key;
void delay(uint z)
{
uint a;
for(z=z;z>0;z--)
for(a=114;a>0;a--);
}

void Write_dat(uchar dat)
{
P0=dat;
rs=1;
en=0;
delay(5);
en=1;
delay(5);
en=0;
}

void Write_com(uchar com)
{
P0=com;
rs=0;
en=0;
delay(5);
en=1;
delay(5);
en=0;
}

void init()
{
delay(20);
Write_com(0x38);
delay(5);
Write_com(0x0c);
delay(5);
Write_com(0x06);
delay(5);
Write_com(0x01);
delay(5);
}

void miskey()
{
uint temp;
P3=0xfe;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{
delay(4);
temp=P3;
temp=temp&0x0f;
if(temp!=0x0f)
{
delay(4);
temp=P3;
switch(temp)
{
case 0xee:
key=0;break;
case 0xde:
key=1; break;
case 0xbe:
key=2; break;
case 0x7e:
key=3; break;

}
while(temp!=0xf0)
{
temp=P3;
temp=temp&0xf0;
}
Write_dat(tab[key]);
delay(5);
}

}
P3=0xfd;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{ delay(5);
temp=P3;
temp=temp&0xf0;
if(temp=temp&0xf0)
{ temp=P3;
switch(temp)
{ case 0xed:
key=4; break;
case 0xdd:
key=5; break;
case 0xbd:
key=6; break;
case 0x7d:
key=7; break;
}
while(temp!=0xf0)
{ temp=P3; temp=temp&0xf0; }
Write_dat(tab[key]);
delay(5);
}
}
P3=0xfb;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{ delay(5);
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{ temp=P3;
switch(temp)
{ case 0xeb:
key=8; break;
case 0xdb:
key=9; break;
case 0xbb:
key=10; break;
case 0x7b:
key=11; break;
}
while(temp!=0xf0)
{ temp=P3; temp=temp&0xf0; }
Write_dat(tab[key]);
delay(5);
}
}
P3=0xf7;
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{ delay(5);
temp=P3;
temp=temp&0xf0;
if(temp!=0xf0)
{ temp=P3;
switch(temp)
{ case 0xe7:
key=12; break;
case 0xd7:
key=13; break;
case 0xb7:
key=14; break;
case 0x77:
key=15; break;
}
while(temp!=0xf0)
{ temp=P3; temp=temp&0xf0;}
Write_dat(tab[key]);
delay(5);

}
}


}

void main()
{
rw=0;
init();
du=0;
we=0;
Write_com(0x80);
while(1)
{
miskey();
}


}