STM32F030控制AD9851产生10Mhz正弦波(EWARM6.7开发环境)

AD9851是一个DDS芯片，主时钟周期达到180MHz，由外部时钟6倍频得到。

输出频率范围可以从1Hz到70MHz，频率控制精度很高。

参数如下：

输出频率的计算公式如下：

在这里采用datasheet里用的数据使输出频率为10MHz，更改频率控制字W1W2W3W4可以得到其他频率。复位时序：

频率控制字写入时序：

AD9851有两种电路连接方法，并行和串行。在这里采用串行的方式。

将如下main.c程序复制进去，并编译运行

//程序描述：利用STM32F030控制DDS芯片AD9851产生10MHz正弦波信号/**********************************************************

硬件电路端口连接

cpu ad9851

PC0----------WCLK

PC1----------FQUD

PC2----------REST

PA0~PA7--------D0~D7

VCC----------------5V

GND-----------GND----------------GND

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

/* Includes ------------------------------------------------------------------*/

#include "stm32f0xx.h"

/* Private typedef -----------------------------------------------------------*/

/* Private define ------------------------------------------------------------*/

#define uchar unsigned char

#define uint unsigned int

typedef char int8; // -128~127

typedef unsigned char uint8; // 0~255

typedef int int16; // -32768~32767

typedef unsigned int uint16; // 0~65535

typedef long int32; // -2147483648~2147483647

typedef unsigned long uint32; // 0~4294967295

/* Private function prototypes -----------------------------------------------*/

/* Private functions ---------------------------------------------------------*/

static __IO uint32_t TimingDelay;

void RCC_Configuration(void);

void GPIO_Configuration(void);

void TimingDelay_Decrement(void);

void Delay(__IO uint32_t nTime);

void reset_ad9851(void);

void set_ad9851(uint32 ad9851_frq);

/* main program

*param:

*description:

int main(void)

{

RCC_Configuration( );

GPIO_Configuration( );

reset_ad9851( );

set_ad9851(0x0e38e38e); //fout=10MHz

}

//Initial the system clock

void RCC_Configuration(void)

{

RCC_ClocksTypeDef RCC_Clocks;

RCC_GetClocksFreq(&RCC_Clocks);

SysTick_Config(RCC_Clocks.HCLK_Frequency / 1000);

/* GPIOC Periph clock enable */

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC, ENABLE);

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

}

/* Configure PC8 and PC9 in output pushpull mode */

void GPIO_Configuration(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 ;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;

GPIO_Init(GPIOC, &GPIO_InitStructure);

}

//sub fuction

void Delay(__IO uint32_t nTime)

{

TimingDelay = nTime;

while(TimingDelay != 0);

}

void TimingDelay_Decrement(void)

{

if (TimingDelay != 0x00)

{

TimingDelay--;

}

//step1:reset the ad9851

void reset_ad9851(void)

{

int reset_i;

GPIO_SetBits(GPIOC , GPIO_Pin_2);

for(reset_i=20; reset_i>0; reset_i--);

GPIO_ResetBits(GPIOC , GPIO_Pin_2);

for(reset_i=200; reset_i>0; reset_i--);

}

//step2:write the frequency and phase parameter to the ad9851

void set_ad9851(uint32 ad9851_freg)

{

uint8 w[5];

uint8 i=0;

int set_i;

w[0]=9;

w[1]=(ad9851_freg&0xff000000)>>24;

w[2]=(ad9851_freg&0x00ff0000)>>16;

w[3]=(ad9851_freg&0x0000ff00)>>8;

w[4]=(ad9851_freg&0x000000ff);

GPIO_ResetBits(GPIOC , GPIO_Pin_1);

for(i=0;i<5;i++)

{

GPIO_ResetBits(GPIOC , GPIO_Pin_0);