main.c

凌阳单片机控制的DDS芯片AD9851（串行和并行控制方式）

#include"SPCE061A.H"
#define  w_clk 0x0100//控制字载入时钟，上升沿
#define FQ_UD 0x0200//频率转换控制，上升沿
#define  RESET 0x0400//复位
#define Fosc   20e+6 //20M晶振
unsigned int KeyFlag=0;//按键标志
unsigned int key;
typedef struct
{  unsigned int W0;
   unsigned int W1;
   unsigned int W2;
   unsigned int W3;
   unsigned int W4;
}ctrl_word;
ctrl_word *cmd_word;
main()
{   
	//initial();//系统初始化
	fstep(1000,1);//系统默认频率
	pstep(0);
	update();
	while(1)
	 *P_Watchdog_Clear=0x0001;	
}   
 void fstep(unsigned long Hz,unsigned int flag)//频率步进
{	
	unsigned long temp;
	if(cmd_word->W0&0x01)
		temp=(unsigned long)(Hz*4294967296)/(6*Fosc);
	else
		temp=(unsigned long)(Hz*4294967296)/Fosc;
	if(flag)
	{
	cmd_word->W1+=(temp&0xff000000>>24);
	cmd_word->W2+=(temp&0x00ff0000>>16);
	cmd_word->W3+=(temp&0x0000ff00>>8);
	cmd_word->W4+=(temp&0x000000ff);
	}
	else
	{
	cmd_word->W1-=temp&0xff000000>>24;
	cmd_word->W2-=temp&0x00ff0000>>16;
	cmd_word->W3-=temp&0x0000ff00>>8;
	cmd_word->W4-=temp&0x000000ff;	
	}
}
void pstep(unsigned int dec)//相位步进
{
	if(cmd_word->W0>>3<32)
	cmd_word->W0=(cmd_word->W0+(dec*32/360)<<3)|0x0001;
}
void update(void)
{
	*P_IOA_Dir=0xffff;
	*P_IOA_Attrib=0xffff;
	*P_IOA_Data=0x00ff;
	*P_IOA_Data=RESET;//复位
     delay(10);  
	*P_IOA_Data=cmd_word->W0;//W0
	*P_IOA_Data|=w_clk;//载入
	    delay(2);
	*P_IOA_Data=cmd_word->W1;//w1
	 *P_IOA_Data|=w_clk;
	    delay(2);
	  *P_IOA_Data=cmd_word->W2; //w2
	  *P_IOA_Data|=w_clk;
	    delay(2);
	  *P_IOA_Data=cmd_word->W3;//w3
	  *P_IOA_Data|=w_clk;
	   delay(2);
	  *P_IOA_Data=cmd_word->W4;//w4
	  *P_IOA_Data|=w_clk;
	   delay(2);
	  *P_IOA_Data=FQ_UD;  //频率刷新
	   delay(10);	
}
/*void initial(void)
{   
   *P_SystemClock=0x0080;
	cmd_word->W0=0;
    cmd_word->W1=0;
    cmd_word->W2=0;
    cmd_word->W3=0;
    cmd_word->W4=0;
	*P_IOA_Dir=0xffff;
	*P_IOA_Attrib=0xffff;
	*P_IOA_Data=0x00ff;
    delay(10);  
           
}*/
void delay(unsigned int time)
{
   while(time--);
   *P_Watchdog_Clear=0x0001;
}