/*8279鍵盤和 LED顯 示程序* /         
/*此程序響應8279的鍵盤中斷，并根據按鍵來更新LED 顯示 */

#include<reg51.h>
#include<absacc.h>
#include<yh.h>

bit int_flag=0; /*中斷標志位*/
uchar key_value;/*中斷返回鍵值 */
uchar js;
/*共陰的七段數碼管譯碼0 1  2    3   4    5    6    7    8   9  a   b    c   d   e    f*/
uchar code table[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71};
uchar code sinbo[]={0x80,0x83,0x86,0x8D,0x90,0x96,0x99,0x9C,0x9f,0xa2,0xa5,0xa8,0xab,0xae,0xb1,0xb4,
					0xb7,0xba,0xbc,0xbf,0xc2,0xc5,0xc7,0xca,0xcf,0xd1,0xd4,0xd6,0xd8,0xda,0xdd,0xdf,
					0xe1,0xe3,0xe5,0xe7,0xe9,0xea,0xec,0xee,0xef,0xf1,0xf2,0xf4,0xf5,0xf6,0xf7,0xf8,
					0xf9,0xfa,0xfb,0xfc,0xfd,0xfd,0xfe,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
					0xff,0xff,0xff,0xfe,0xfd,0xfd,0xfc,0xfb,0xfa,0xf9,0xf8,0xf7,0xf6,0xf5,0xf4,0xf2,
					0xf1,0xef,0xee,0xec,0xeb,0xea,0xe9,0xe7,0xe5,0xe3,0xe1,0xdf,0xdd,0xda,0xd8,0xd6,
					0xd4,0xd1,0xcf,0xcc,0xca,0xc7,0xc5,0xc2,0xbf,0xbc,0xba,0xb7,0xb4,0xb1,0xae,0xab,
					0xa8,0xa5,0xa2,0x9f,0x9c,0x99,0x96,0x93,0x90,0x8d,0x89,0x86,0x83,0x80,0x7c,
					0x79,0x76,0x72,0x6f,0x6c,0x69,0x66,0x63,0x60,0x5d,0x5a,0x57,0x55,0x51,0x4e,0x4c,
					0x48,0x45,0x43,0x40,0x3d,0x3a,0x38,0x35,0x33,0x30,0x2e,0x2b,0x29,0x27,0x25,0x22,
					0x20,0x1e,0x1c,0x1a,0x18,0x16,0x15,0x13,0x11,0x10,0x0e,0x0d,0x0b,0x0a,0x09,0x08,
					0x07,0x06,0x04,0x03,0x02,0x02,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
					0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0d,0x0e,
					0x10,0x11,0x13,0x15,0x16,0x18,0x1a,0x1c,0x1e,0x20,0x22,0x25,0x27,0x29,0x2b,0x2e,
					0x30,0x33,0x35,0x38,0x3a,0x3d,0x40,0x43,0x45,0x48,0x4c,0x4e,0x51,0x55,0x57,0x5a,
					0x5b,0x60,0x63,0x66,0x69,0x6c,0x6f,0x72,0x76,0x79,0x7c,0x80};




///////////////////////////////////////////////////////////////////////////////

//讀取鍵盤數據，返回當前被按下的鍵號	 
uchar keyin(void)
{
 	uchar i;
 	COM8279=0x40;
	i=DAT8279;
	i=i&0x3f; //取鍵盤數據低7位
 	return(i);
}


void main(void)
{	
	//////////////////////////////////////////////////////////////////////////////
	//初始化單片機  
	AUXR = 0x02;/*STC單片機關內部RAM和開ALE*/

	delay(1000);
	//////////////////////////////////////////////////////////////////////////////
	//初始化8279
 	COM8279=0xd1;//1101 0001b 清除所有顯示  
 	do{ACC=COM8279;}
	while(clflag==1);   //清除起來比較慢，所以一條指令執行的時間不足以完成所有清除，故需等待		  
    COM8279=0x00;			
	DA0832=0; 
	COM8255=0x80;	   //pa,pb以方式0工作，三個口都是輸出 
 	COM8255=0x80;
	COM8255=0x80; 
	IE=0x83;             //開中斷 
//    IE=0x81;
	TCON=0x01;        		  
	TMOD=0x00;           //用定時器0，方式0	 
	TH0=0x0F4;
    TL0=0x010;
    TR0=1;
 	//////////////////////////////////////////////////////////////////////////////

    //大循環 
 	while(1)
 	{  
		while(int_flag==0)  /*等待中斷 */
		{
		    //此處可填入后臺程序  
		}
		
		int_flag=0;

        //根據鍵值調用鍵盤響應函數	  
		switch(key_value)
		{
			case 0x00:key0();break;
			case 0x01:key1();break;
	 		case 0x02:key2();break;
	 		case 0x03:key3();break;
	 		case 0x08:key4();break;
			case 0x09:key5();break;
	 	
	 		default:break;
		}
 	}
}

//INT0的中斷服務函數   
//INT0由8279在鍵盤按下時發出    
//注意關鍵字interrupt
void int_int0() interrupt 0 using 0
{
  	//設置標志，告訴主循環中斷發生了   
  	int_flag=1;
  	//讀取鍵值 
	key_value=keyin();
}


void DA_time0() interrupt 1 using 1
{
  
  TR0=0;
  TH0=0x0F4;
  TL0=0x010;
  //DA0832 5Hz 正弦波輸出   			   
  DA0832=sinbo[js];
  js++;
  if(js==251)
    js=0;
  
  TR0=1;
}