#include <AT89X52.H>
sbit rs=P0^0;      //寄存器類型選擇位
sbit rw=P0^1;      //數據讀寫類型控制位
sbit e=P0^2;       //下降沿使能控制位
sbit flag=ACC^7;   //LCD忙狀態判斷標志位
void wait(void);
void delay(unsigned int temp);
void initial(void);
unsigned char code seg[]={0x43,0x68,0x69,0x6E,0x61,0x20,0x55,0x6E,0x69,0x76,    //China University of Mining and
                            0x65,0x72,0x73,0x69,0x74,0x79,0x20,0x6F,0x66,0x20,  //Techlonogy    17--302
									 0x4D,0x69,0x6E,0x69,0x6E,0x67,0x20,0x61,0x6E,0x64,
									 0x20,0x20,0x54,0x65,0x63,0x68,0x6C,0x6F,0x6E,0x6F,0x67,
									 0x79,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x5C,0x5C,
									 0x31,0x37,0x2D,0x2D,0x33,0x30,0x32,0x5C,0x5C,0x20,0x20,0x20};
void main(void){
      unsigned char data_index;
	   unsigned char add_first,add_second,add_third,add_fourth;     //LCD行地址為80H，C0H，90H，D0H
      initial();        //初始化LCD
      while(1){     
		               data_index=0;add_first=0x80;add_second=0xC0;add_third=0x90;add_fourth=0xD0;
		               while(data_index<=15){   
	                      rs=0;rw=0;P2=add_first+data_index;e=1;e=0;    //第一行顯示
								 wait();
								 rs=1;rw=0;P2=seg[data_index];e=1;e=0;
								 wait();	
		 						 data_index++;
			           }
						  while(data_index<=31){                           //第二行顯示
	                      rs=0;rw=0;P2=add_second+data_index-16;e=1;e=0;
								 wait();
								 rs=1;rw=0;P2=seg[data_index];e=1;e=0;
								 wait();
		 						 data_index++;
			           }
						  while(data_index<=47){                          //第三行顯示
	                      rs=0;rw=0;P2=add_third+data_index-32;e=1;e=0;
								 wait();
								 rs=1;rw=0;P2=seg[data_index];e=1;e=0;
								 wait();	
		 						 data_index++;
			           }
						  while(data_index<=63){                        //第四行顯示
	                      rs=0;rw=0;P2=add_fourth+data_index-48;e=1;e=0;
								 wait();
								 rs=1;rw=0;P2=seg[data_index];e=1;e=0;
								 wait();	
		 						 data_index++;
			           }
	  }
}
void initial(void){
           rs=0;rw=0;P2=0x3C;   //置功能，8位數據位，2行顯示,5×7點陣
			  e=1; e=0;wait();
			  rs=0;rw=0;P2=0x06;   //地址計數器自動加1，顯示屏不移動
			  e=1;e=0;wait(); 
			  rs=0;rw=0;P2=0x0E;   //顯示開，光標顯示，光標閃爍
			  e=1;e=0;wait();
			  rs=0;rw=0;P2=0x01;   //清顯示，光標復位到00H
			  e=1;e=0;wait();
}
void wait(void){                   //判斷LCD處于空閑狀態
             do{
                  rs=0;rw=1;
                  e=1;
						e=0;delay(0);
                  P2_7=1;flag=P2_7;
               }while(flag==0);
              
}
void delay(unsigned int temp){
      unsigned int jj;
		for(jj=0;jj<=temp;jj++)
		;
}