dds9852.c

c8051f020+ad9852＋12864＋键盘（频率合成）贝一特电子

#include <main.h>
#include <math.h>

#define ad9852_D     P1
#define ad9852A_Ctrl P2

sbit ddsRST   =P3^5 ;
sbit ddsWR    =P3^4 ;

unsigned char Mul_fctrl=4,M_ctrl=0,PLL_BPnum=0x20;	   //disable PLL
unsigned long F0ctrl_word=0;                           //频率
unsigned char AD9852_F0[6];

/*****************写地址，写数据**************************/
void Write_AD9852(unsigned char ADDR,unsigned char WRdata)
{  
   ad9852A_Ctrl =ADDR;
   ad9852_D=WRdata;
   ddsWR=0;
   ddsWR=1;
}

/**********************工作模式选择***********************/

void WR_AD9852Mode(unsigned char M_ctrl)
{   
   Write_AD9852(0x1F,0x01|(M_ctrl<<1));
}
/**********************DDS初使化************************/
void ddsInit()
{ 
   unsigned char i;
   for(i=15;i>0;i--); 
   ddsRST=0;
   for(i=15;i>0;i--); 
   ddsRST=1;
   for(i=15;i>0;i--); 
   ddsRST=0;
   ddsWR=1;

   Write_AD9852(0x1F,0X01);    //普通模式，内部更新时钟
   Write_AD9852(0x20,0x40);	 //旁路反正弦
		
}
/*******************DDS开始***********************/
void start_dds(F0ctrl_word)
{	  
      unsigned char i; 
      for(i=0;i<4;i++)
	  {  
	     AD9852_F0[i+2]=(unsigned char)( (long)(F0ctrl_word*85.89934592) >>(8*i) );		//f250m=17.179869184
         Write_AD9852((7-i),AD9852_F0[i+2]);											//f50m=
	  }	  	   
}