单片机控制点阵LED一秒刷新显示I心形U

下面是程序源码:
/******点阵LED刷新显示I LVOE U**************/
/**
*功能：点阵LED一秒刷新显示I 心形 U（I LOVE YOU）
*作者：徐冉
*日期：2013-06-14-22：44
*备注：程序已调试成功
**/
/*************AT89C52-RC MCU*******************/
/**************51hei开发板********************/
#include
typedef unsigned int uint;
typedef unsigned char uchar;
sbit din = P2^0;
sbit cs = P2^1;
sbit clk = P2^2;
uchar code table[5][8] = {
   {0x00,0x3C,0x18,0x18,0x18,0x18,0x3C,0x00}, //'I'
   {0x00,0x66,0xFF,0xFF,0xFF,0x7E,0x3C,0x18},  //'心'
   {0x00,0x66,0x66,0x66,0x66,0x7E,0x3C,0x00},  //'U'
          };
uchar i, j;
uint counter;
//写字节
void write_byte(uchar date)
{
 uchar i;
 cs = 0;
 for(i = 0; i < 8; i++)
 {
  clk = 0;
  din = date & 0x80;
  date <<= 1;
  clk = 1;
 }
}
//写MAX7219
void write_max7219(uchar add, uchar date)
{
 cs = 0;
 write_byte(add);
 write_byte(date);
 cs = 1;
}
//MAX7219初始化
void max7219_init()
{
 write_max7219(0x0c, 0x01);//正常模式 
 write_max7219(0x09, 0x00);//译码模式
 write_max7219(0x0a, 0x08);//亮度控制
 write_max7219(0x0b, 0x07);//扫描模式
 write_max7219(0x0f, 0x00);//显示检测
}
//定时器T0初始化
void timer0_init()
{
 TMOD = 0x01;
 TH0 = 0x94; //定时30ms
 TL0 = 0x00;
 TR0 = 1;
 EA = 1;
 ET0 = 1;
}
//主程序
void main(void)
{
 max7219_init();
 timer0_init(); 
 while(1)
 {
   if(i >= 8)
   {
    i = 0;
   }
   if(counter == 40)
   {
    counter = 0;
    j++;
    if(j >= 3)
    {
     j = 0;
    }
   }
   write_max7219(i+1, table[j][i]);
 }
}
//中断服务程序
void timer0_int() interrupt 1
{
 TH0 = 0x94;
 TL0 = 0x00; 
    i++;
 counter++;
}