通常dds的程序是在51单片机实现的，最近我在DSP环境下，实现了对AD9851进行配置，下面分享一下程序吧~

/AD9851的I/O控制口宏定义

#define DDS_W_CLK GpioDataRegs.GPADAT.bit.GPIOA12
#define DDS_FQ_UD GpioDataRegs.GPADAT.bit.GPIOA13
#define DDS_RESET GpioDataRegs.GPADAT.bit.GPIOA14
#define DDS_D7   GpioDataRegs.GPADAT.bit.GPIOA15

//AD9851相关函数申明
void AD9851_Init(void);
void Write_AD9851(Uint32 dds);
void AD9851_Change(Uint32 freq);

/-------------------------------------------------------------------------------
-AD9851.c
-------------------------------------------------------------------------------/

#include "DSP28_Device.h"

//AD9851初始化
void AD9851_Init(void)
{

unsigned int i;
unsigned int Serial_Mode = 0x03;
EALLOW;
//作为一般I/O口
GpioMuxRegs.GPAMUX.bit.TCLKINA_GPIOA12=0;
GpioMuxRegs.GPAMUX.bit.C1TRIP_GPIOA13 =0;
GpioMuxRegs.GPAMUX.bit.C2TRIP_GPIOA14 =0;
GpioMuxRegs.GPAMUX.bit.C3TRIP_GPIOA15 =0;
//选择I/O口作为输出
GpioMuxRegs.GPADIR.bit.GPIOA12=1;
GpioMuxRegs.GPADIR.bit.GPIOA13=1;
GpioMuxRegs.GPADIR.bit.GPIOA14=1;
GpioMuxRegs.GPADIR.bit.GPIOA15=1;
EDIS;
DDS_W_CLK=0;
DDS_FQ_UD=0;
DDS_RESET=0;
DDS_RESET=1;
DelayUs(10000);
DDS_RESET=0;
DelayUs(10000);
//配置串行方式
    for (i = 0;i < 8;i++)
    {
        DDS_W_CLK=0;
        if (Serial_Mode & 0x01)
        {
            DDS_D7=1;
        }
        else
        {
            DDS_D7=0;
        }
        DDS_W_CLK=1;
        Serial_Mode = Serial_Mode >> 1;
   DelayUs(1000);
    }
    DDS_FQ_UD=1;
    DelayUs(2000);
    DDS_FQ_UD=0;
    DDS_W_CLK=0;

}

//频率

void AD9851_Change(Uint32 freq)
{
Uint32 dds;
dds = freq * 23.860929422 ;
    Write_AD9851(dds);
}
//写数据

void Write_AD9851(Uint32 dds)
{
    unsigned int i;
    DDS_W_CLK=0;
    DDS_FQ_UD=0;
    for (i = 0;i < 40;i++)
    {
        DDS_W_CLK=0;
   DelayUs(2000);
        if((dds&0x00000001)||(i==32)) //取数据，6倍频使能
        {
            DDS_D7=1;
        }
        else
        {
            DDS_D7=0;
        }
        DDS_W_CLK=1;
   DelayUs(2000);
        dds = dds >> 1;
    }
DDS_FQ_UD=1;
DDS_W_CLK=0;
DelayUs(2000);
DDS_FQ_UD=0;
}