DDS AD9959應(yīng)用電路和配置源程序

AD9959是一款有四個DDS通道，最高達(dá)500M SPS的數(shù)字頻率合成芯片。

        常用電路接法：

主要程序：

#include "config.h"
void delay(void)
{
 unsigned int i;
 for(i=0;i<10;i++);
}

/*****************************************************************************

功能描述: 加載寄存器，上升延有效



*****************************************************************************/
void run(void)
{
 CLR_IOUPDATE;
 CLR_IOUPDATE;
 CLR_IOUPDATE;
 CLR_IOUPDATE;
 CLR_IOUPDATE;
 CLR_IOUPDATE;
 CLR_IOUPDATE;
 
 
 SET_IOUPDATE;
 SET_IOUPDATE;   
}

/*****************************************************************************
函數(shù)名: write_a_byte

功能描述: 通過串口寫一個字節(jié)，MSB first，上升延有效



*****************************************************************************/
void write_a_byte(uint8 w_data)
{
 uint8 i;    
 for(i=0;i<8;i++)
  {
   if(w_data & 0x80)
   {
    SET_SDIO0;
   }
   else
   {
    CLR_SDIO0;
   }
   w_data <<= 1;
   SET_DDSSCLK;
   CLR_DDSSCLK;
  }
}

/*****************************************************************************
函數(shù)名: write_CSR

功能描述: 寫CSR寄存器：

*****************************************************************************/
void write_CSR(uint8 w_data)
{
 CLR_SDIO3;
 CLR_DDSCS;
 write_a_byte(0x00);    //write address 0.  CSR's address is 0.
 write_a_byte(w_data);
 SET_DDSCS;
 SET_SDIO3;
}

void write_FR1(uint8 w_data1,uint8 w_data2,uint8 w_data3)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x01);    //write address 1.  FR1's address is 0x01
 write_a_byte(w_data1);
 write_a_byte(w_data2);
 write_a_byte(w_data3);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_FR2(uint8 w_data1,uint8 w_data2)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x02);    //write address 2
 write_a_byte(w_data1);
 write_a_byte(w_data2);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_CFR(uint8 w_data1,uint8 w_data2,uint8 w_data3)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x03);
 write_a_byte(w_data1);
 write_a_byte(w_data2);
 write_a_byte(w_data3);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_CTW0(uint32 F_word)  //Channel Frequency Tuning Word  (CTW0)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x04);
 write_a_byte(((unsigned char *)(&F_word))[3]);
 write_a_byte(((unsigned char *)(&F_word))[2]);
 write_a_byte(((unsigned char *)(&F_word))[1]);
 write_a_byte(((unsigned char *)(&F_word))[0]);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_CPW0(uint16 P_word)                  //Channel Phase1 Offset Word (CPW0) (0x05)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x05);
 write_a_byte(((unsigned char *)(&P_word))[1]&0x3F);
 write_a_byte((((unsigned char *)(&P_word))[0]));
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_ACR(uint32 A_word)
{
 CLR_SDIO3;
 CLR_DDSCS;
 write_a_byte(0x06);
 
 write_a_byte(((unsigned char *)(&A_word))[3]);
 write_a_byte(((unsigned char *)(&A_word))[2]);
 write_a_byte(((unsigned char *)(&A_word))[1]);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_LSR(uint8 rising,uint8 falling)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x07);
 write_a_byte(rising);
 write_a_byte(falling);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_RDW(uint32 rising)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x08);
 write_a_byte(((unsigned char *)(&rising))[3]);
 write_a_byte(((unsigned char *)(&rising))[2]);
 write_a_byte(((unsigned char *)(&rising))[1]);
 write_a_byte(((unsigned char *)(&rising))[0]);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_FDW(uint32 falling)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(0x09);
 write_a_byte(((unsigned char *)(&falling))[3]);
 write_a_byte(((unsigned char *)(&falling))[2]);
 write_a_byte(((unsigned char *)(&falling))[1]);
 write_a_byte(((unsigned char *)(&falling))[0]);
 
 SET_DDSCS;
 SET_SDIO3;
}

void write_CTWn(uint8 n,uint32 w_data)
{
 CLR_SDIO3;
 CLR_DDSCS;
 
 write_a_byte(n+0x09);   //CTWn's address is n+0x09.n>=1 and n<=15.
 write_a_byte(((unsigned char *)(&w_data))[3]);
 write_a_byte(((unsigned char *)(&w_data))[2]);
 write_a_byte(((unsigned char *)(&w_data))[1]);
 write_a_byte(((unsigned char *)(&w_data))[0]);
 
 SET_DDSCS;
 SET_SDIO3;
}

#define PLL_DIV 5
#define systemp_frequency (22.1184*1000000*PLL_DIV)

void set_frequency(uint32 f)
{
 unsigned long int temp;
 temp=(unsigned long int)f*(0xFFFFFFFF/(float)systemp_frequency+1.0/systemp_frequency);
 write_CTW0(temp);
}

uint32 change(uint32 f)
{
 unsigned long int temp;
 temp=(unsigned long int)f*(0xFFFFFFFF/(float)systemp_frequency+1.0/systemp_frequency);
 return temp;
}

void AD9959_init(void)
{
 uint16 i;
 DDS_DDR = 0xff;
 CLR_DDSRESET;
 for(i=0;i<10000;i++);
 
 SET_DDSCS;
 CLR_DDSSCLK;
 SET_SDIO3;
 SET_DDSRESET;
 
 for(i=0;i<10000;i++);
 
 CLR_DDSRESET;
 for(i=0;i<100;i++);
}