//程序：ex6_5.c
//功能：產(chǎn)生正弦波，周期約256ms，幅度約2.5V
#include <absacc.h>		  //絕對(duì)地址訪(fǎng)問(wèn)頭文件
#include <reg51.h>
#define uint unsigned int
#define uchar unsigned char 
#define DA0832 XBYTE[0x7fff]
void delay_1ms()；        	//延時(shí)
uchar code sin[]={0x80,0x83,0x86,0x89,0x8D,0x90,0x93,0x96,0x99,0x9C,0x9F,
0xA2,0xA5,0xA8,0xAB,0xAE,0xB1,0xB4,0xB7,0xBA,0xBC,0xBF,0xC2,0xC5,0xC7,0xCA,0xCC,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,0xEA,0xE9,0xE7,0xE5,0xE3,0xE1,0xDF,0xDD,0xDA,0xD8,0xD6,0xD4,0xDl,0xCF,0xCC,0xCA,0xC7,0xC5,0xC2,0xBF,0xBC,0xBA,0xB7,0xB4,0xB1,0xAE,0xAB,0xA8,0xA5,0xA2,0x9F,0x9C,0x99,0x96,0x93,0x90,0x8D,0x89,0x86,0x83,0x80,0x80,0x7C,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,0x09,0x08,0x07,0x06,0x05,0x04,0x03,0x02,0x02,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x02,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,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,0x5D,0x60,0x63,0x66,0x69,0x6C,0x6F,0x72,0x76,0x79,0x7C,0x80};
void main()			// 主函數(shù)
{	
   uchar i;
   TMOD=0x10;         		// 置定時(shí)器1為方式1
   while(1)
   {	
      for(i=0;i<=255;i++)	//形成正弦輸出
      {	
         DA0832=sin[i];		//D/A轉(zhuǎn)換輸出
	 delay_1ms();
      }
   }
}
//函數(shù)名：delay_1ms
//函數(shù)功能：延時(shí)1ms，T1、工作方式1，定時(shí)初值64536
//形式參數(shù)：無(wú)
//返回值：無(wú)
void delay_1ms()
{ 
   TH1=0xfc;				// 置定時(shí)器初值
   TL1=0x18;
   TR1=1;		               	// 啟動(dòng)定時(shí)器1
   while(!TF1);  	           	// 查詢(xún)計(jì)數(shù)是否溢出，即定時(shí)1ms時(shí)間到，TF1=1
   TF1=0;			   	// 1ms時(shí)間到，將定時(shí)器溢出標(biāo)志位TF1清零
}