用12864下半屏显示图形。为何上半屏会花屏呢

#include<reg52.h>
#include<intrins.h>

#define uchar unsigned char
#define uint unsigned int

uchar code table2[]={
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x1E,0x00,0x00,0x00,0x00,0x00,0x07,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x00,0x7F,0x80,0x00,0x00,0x00,0x00,0x18,0x0C,0x00,0x00,0x01,0x00,0x00,0x00,0x00,
0x01,0xFF,0x80,0x00,0x00,0x00,0x00,0x20,0x00,0x00,0x00,0x13,0x10,0x03,0xFE,0x00,
0x03,0xFF,0xC0,0x00,0x00,0x00,0x00,0x58,0x00,0x00,0x00,0x3F,0x30,0x1F,0xFF,0xC0,
0x03,0xFF,0xE0,0x00,0x00,0x00,0x00,0x8C,0x03,0xF0,0x00,0x7F,0xE0,0x7C,0x01,0xE0,
0x03,0xFF,0xF0,0x00,0x00,0x00,0x01,0x36,0x06,0xC0,0x00,0x5F,0xC0,0xFF,0xFC,0x60,
0x01,0xFF,0xF0,0x00,0x00,0x00,0x02,0x1B,0x0F,0x80,0x00,0xFF,0x01,0xFE,0x0F,0x30,
0x00,0xEF,0xF0,0x00,0x00,0x00,0x02,0x6D,0x9F,0x00,0x00,0x3E,0x03,0xFF,0xF1,0x90,
0x00,0xFF,0xF8,0x00,0x00,0x00,0x04,0x36,0xFE,0x00,0x01,0xFF,0x07,0xFF,0xFC,0x90,
0x00,0xEF,0xFF,0xFF,0x80,0x00,0x04,0xDB,0x7E,0x00,0x03,0xFF,0x87,0xFF,0xFC,0xD0,
0x00,0x0F,0xFF,0xFF,0xC0,0x00,0x04,0x6D,0xFC,0x00,0x07,0xFF,0x8F,0xFF,0xFE,0x50,
0x00,0x0F,0xFF,0xFF,0xE0,0x00,0x04,0x36,0xFC,0x10,0x07,0xFF,0x8F,0xFF,0xFE,0x90,
0x00,0x0F,0xFF,0xFF,0xE0,0x00,0x04,0x1B,0xF8,0x10,0x07,0xFF,0xCF,0xFF,0xFE,0x80,
0x00,0x0F,0xFF,0xFF,0xF0,0x00,0x04,0x0F,0xF8,0x10,0x07,0xFF,0xFF,0xFF,0xFA,0x00,
0x00,0x07,0xFF,0xFF,0xF0,0x00,0x04,0x07,0xF0,0x10,0x07,0xFF,0xFF,0xFF,0xFA,0x00,
0x00,0xFF,0xFF,0xFF,0xF8,0x00,0x02,0x03,0xF0,0x20,0x07,0xFF,0xFF,0xFF,0xBA,0x00,
0x00,0xFD,0xFF,0xFF,0xFC,0x00,0x02,0x03,0xF0,0x20,0x03,0xFF,0xFF,0xDF,0xB8,0x00,
0x00,0xC1,0xC0,0x3F,0xFC,0x00,0x01,0x01,0xE0,0x40,0x00,0xFF,0xFF,0xDF,0xB0,0x00,
0x00,0x81,0xC0,0x3F,0xCE,0x00,0x00,0x81,0xE0,0x80,0x00,0x7F,0xFF,0xDF,0xA0,0x00,
0x00,0x81,0x80,0x1D,0xCF,0x00,0x00,0x41,0xE1,0x00,0x00,0x3F,0xFF,0x9B,0x00,0x00,
0x01,0x83,0x80,0x1F,0xC7,0x80,0x00,0x21,0xE2,0x00,0x00,0x1F,0xFD,0xB6,0x00,0x00,
0x01,0xC3,0x00,0x0E,0xE6,0x80,0x00,0x19,0xEC,0x00,0x00,0x07,0xFE,0x20,0x00,0x00,
0x00,0xC3,0x00,0x07,0x67,0x40,0x00,0x07,0xF0,0x00,0x00,0x03,0x3E,0x00,0x00,0x00,
0x00,0x02,0x00,0x03,0xE7,0xA0,0x00,0x00,0x00,0x00,0x00,0x02,0x8E,0x00,0x00,0x00,
0x00,0x06,0x00,0x03,0x83,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x03,0x00,0x00,0x00,
0x00,0x06,0x00,0x07,0x03,0x00,0x77,0x46,0x74,0x24,0x80,0x06,0x04,0x00,0x00,0x00,
0x00,0x1C,0x00,0x06,0x00,0x00,0x55,0x45,0x54,0x57,0x80,0x00,0x00,0x00,0x00,0x00,
0x00,0x1C,0x00,0x0E,0x00,0x00,0x45,0x45,0x74,0x57,0x80,0x08,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x1C,0x00,0x00,0x55,0x45,0x44,0x74,0x80,0xF0,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x38,0x00,0x00,0x77,0x76,0x47,0x54,0x80,0x00,0x00,0x00,0x00,0x00,
0x00,0x00,0x00,0x00,0x00,0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
};


sbit rs = P3^0;
sbit rw = P3^1;
sbit en = P3^2;
sbit psb= P3^3;
sbit rst= P3^5;

sbit busy=P0^7;
uchar y=0x80;
uchar x1=0x80;
uchar x2=0x88;



void check_busy()
{
P0=0xff;
rs=0;
rw=1;
en=1;
_nop_();
while(busy==1);
en=0;
}


void write_cmd12864( uchar cmd)
{
check_busy();
rs=0;
rw=0;
P0=cmd;
en=1;
_nop_();
en=0;
}

void write_dat12864(uchar dat)
{
check_busy();
rs=1;
rw=0;
P0=dat;
en=1;
_nop_();
en=0;
}

void init12864()
{
rst=1;
psb=1;
write_cmd12864(0x30);
write_cmd12864(0x01);
write_cmd12864(0x06);
write_cmd12864(0x0c);
}


void bottom_dis(uchar *img)
{
uchar i,j;
for(j=0;j<32;j++)
{
for(i=0;i<8;i++)
{
write_cmd12864(0x34);
write_cmd12864(y+j);
write_cmd12864(x2+i);
write_cmd12864(0x30);
write_dat12864(img[j*16+i*2]);
write_dat12864(img[j*16+i*2+1]);
}
// write_cmd12864(0x36);
}
write_cmd12864(0x36);
}





main()
{
//uint i,j;
SP=0x5f;
init12864();
bottom_dis(table2);
/* write_cmd12864(0x01);
for(j=0;j<32;j++)
{
for(i=0;i<8;i++)
{
write_cmd12864(0x34);
write_cmd12864(j+y);
write_cmd12864(x2+i);
write_cmd12864(0x30);
write_dat12864(table2[j*16+i*2]);
write_dat12864(table2[j*16+i*2+1]);

}
// write_cmd12864(0x36);
}
write_cmd12864(0x36);*/

while(1);


}