/*****************************************************************
                 簡易正弦波\三角波\方波發生器
                 使用keil C51,12MHZ晶振,AT89C2051
                  2005.03.25通過測試
******************************************************************/
#include "reg51.h"
#define uchar unsigned char
#define uint  unsigned int
#define key  P3            //鍵盤口
#define dataout P1        //正弦波等數據輸出口
//
/*************************正弦波數據表*****************************/
uchar code sin_tab[256]=
      {0x80,0x83,0x85,0x88,0x8A,0x8D,0x8F,0x92,
       0x94,0x97,0x99,0x9B,0x9E,0xA0,0xA3,0xA5,
       0xA7,0xAA,0xAC,0xAE,0xB1,0xB3,0xB5,0xB7,
       0xB9,0xBB,0xBD,0xBF,0xC1,0xC3,0xC5,0xC7,
       0xC9,0xCB,0xCC,0xCE,0xD0,0xD1,0xD3,0xD4,
       0xD6,0xD7,0xD8,0xDA,0xDB,0xDC,0xDD,0xDE,
       0xDF,0xE0,0xE1,0xE2,0xE3,0xE3,0xE4,0xE4,
       0xE5,0xE5,0xE6,0xE6,0xE7,0xE7,0xE7,0xE7,
       0xE7,0xE7,0xE7,0xE7,0xE6,0xE6,0xE5,0xE5,
       0xE4,0xE4,0xE3,0xE3,0xE2,0xE1,0xE0,0xDF,
       0xDE,0xDD,0xDC,0xDB,0xDA,0xD8,0xD7,0xD6,
       0xD4,0xD3,0xD1,0xD0,0xCE,0xCC,0xCB,0xC9,
       0xC7,0xC5,0xC3,0xC1,0xBF,0xBD,0xBB,0xB9,
       0xB7,0xB5,0xB3,0xB1,0xAE,0xAC,0xAA,0xA7,
       0xA5,0xA3,0xA0,0x9E,0x9B,0x99,0x97,0x94,
       0x92,0x8F,0x8D,0x8A,0x88,0x85,0x83,0x80,
       0x7D,0x7B,0x78,0x76,0x73,0x71,0x6E,0x6C,
       0x69,0x67,0x65,0x62,0x60,0x5D,0x5B,0x59,
       0x56,0x54,0x52,0x4F,0x4D,0x4B,0x49,0x47,
       0x45,0x43,0x41,0x3F,0x3D,0x3B,0x39,0x37,
       0x35,0x34,0x32,0x30,0x2F,0x2D,0x2C,0x2A,
       0x29,0x28,0x26,0x25,0x24,0x23,0x22,0x21,
       0x20,0x1F,0x1E,0x1D,0x1D,0x1C,0x1C,0x1B,
       0x1B,0x1A,0x1A,0x1A,0x19,0x19,0x19,0x19,
       0x19,0x19,0x19,0x19,0x1A,0x1A,0x1A,0x1B,
       0x1B,0x1C,0x1C,0x1D,0x1D,0x1E,0x1F,0x20,
       0x21,0x22,0x23,0x24,0x25,0x26,0x28,0x29,
       0x2A,0x2C,0x2D,0x2F,0x30,0x32,0x34,0x35,
       0x37,0x39,0x3B,0x3D,0x3F,0x41,0x43,0x45,
       0x47,0x49,0x4B,0x4D,0x4F,0x52,0x54,0x56,
       0x59,0x5B,0x5D,0x60,0x62,0x65,0x67,0x69,
       0x6C,0x6E,0x71,0x73,0x76,0x78,0x7B,0x7D};
//
/***************************三角波數據表**************************/
uchar code thr_tab[256]=
      {0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,
       0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
       0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,
       0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
       0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,
       0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,
       0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,
       0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
       0xBF,0xBE,0xBD,0xBC,0xBB,0xBA,0xB9,0xB8,
       0xB7,0xB6,0xB5,0xB4,0xB3,0xB2,0xB1,0xB0,
       0xAF,0xAE,0xAD,0xAC,0xAB,0xAA,0xA9,0xA8,
       0xA7,0xA6,0xA5,0xA4,0xA3,0xA2,0xA1,0xA0,
       0x9F,0x9E,0x9D,0x9C,0x9B,0x9A,0x99,0x98,
       0x97,0x96,0x95,0x94,0x93,0x92,0x91,0x90,
       0x8F,0x8E,0x8D,0x8C,0x8B,0x8A,0x89,0x88,
       0x87,0x86,0x85,0x84,0x83,0x82,0x81,0x80,
       0x7F,0x7E,0x7D,0x7C,0x7B,0x7A,0x79,0x78,
       0x77,0x76,0x75,0x74,0x73,0x72,0x71,0x70,
       0x6F,0x6E,0x6D,0x6C,0x6B,0x6A,0x69,0x68,
       0x66,0x66,0x65,0x64,0x63,0x62,0x61,0x60,
       0x5F,0x5E,0x5D,0x5C,0x5B,0x5A,0x59,0x58,
       0x55,0x55,0x55,0x54,0x53,0x52,0x51,0x50,
       0x4F,0x4E,0x4D,0x4C,0x4B,0x4A,0x49,0x48,
       0x44,0x44,0x45,0x44,0x43,0x42,0x41,0x40,
       0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,
       0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,
       0x50,0x51,0x52,0x53,0x55,0x55,0x56,0x57,
       0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F,
       0x60,0x61,0x62,0x63,0x66,0x65,0x66,0x67,
       0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
       0x70,0x71,0x72,0x73,0x77,0x75,0x76,0x77,
       0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F};
//
/******************************************************************************/
uint  data  THHL=65535;    //T1的16位定時器初值
uchar data keyword,n=0;    //鍵值存放,查表指針
bdata sinthr;
sbit sin_thr=sinthr^0;  //正弦波\三角波標志(1為正弦波)
sbit ww=key^7;          // 方波輸出口
//
/*******************************鍵掃描子函數***********************************/
keyscan()
{
keyword=key&0x07;
if(keyword!=0x07)
 {
 while((key&0x07)!=0x07);//等待鍵釋放
  switch(keyword)
   {
    case 6:{if(THHL>=65235)THHL=65535;else{THHL=THHL+255;}break;}//
    case 5:{if(THHL<=500)THHL=0;else{THHL=THHL-255;}break;}//
    case 3:{sin_thr=~sin_thr;break;}//
    default:{break;}//
   }
 }
 }
//
/***************************初始化函數****************************************/
clearmen()
{
key=0xff,dataout=0x00;THHL=65535;//按鍵輸入狀態,波形輸出為0
TH1=THHL/256;TL1=THHL%256;//裝定時初值（T1用）
TMOD=0X11;ET1=1;TR1=1;EA=1;//16 位定時模式,T1中斷允許,開定時器,開總中斷
}
//
/*********************************主函數***************************************/
main()
{
clearmen();
while(1)
 {
  keyscan();
  }
}
//
/***********************************T1中斷函數**********************************/
void time_intt1(void) interrupt 3 
{
 EA=0;TR1=0;TH1=THHL/256;TL1=THHL%256;TR1=1;
 if(sin_thr){dataout=sin_tab[n];}
  else {dataout=thr_tab[n];}
 if(n>=255){n=0;}else{ n++;}
 ww=~ww;
 EA=1;
}
//
//***********************************結束****************************************//