main.c

DDS芯片9833的驱动

#include <reg52.h>

#define uint unsigned int
#define uchar unsigned char
sbit dds_en=P1^4;
sbit dds_clk=P1^5;
sbit dds_dat=P1^6;


void delay(uint k)
{
	while (--k);
}

void write_2byte(uint a)	 //写2BYTE到DDS
{
	uchar i;
	dds_clk=1;
	dds_dat=1;
	dds_en=1;
//	control=0;
	delay(1000);
	dds_clk=1;
	delay(2);
	dds_en=0;
	for(i=0;i<16;i++)
		{
			if(a&0x8000){dds_dat=1;}//the MSB=1
			else dds_dat=0;//the MSB=0
			dds_clk=0;
			delay(5);
			dds_clk=1;
			a=a<<1;
		}
	delay(2);
	dds_en=1;
	dds_clk=0;
	delay(1000);
//	control=1;
}

void init_dds(void)//初始化DDS芯片
{
	write_2byte(0x2100);
	write_2byte(0x2000);//write command;28mode;
	write_2byte(0x4000);//write LSB of freq0 reg  置入00FC000
	write_2byte(0x403F);//write MSB of freq0 reg
	write_2byte(0x2900);
	write_2byte(0x8000);//write LSB of freq1 reg  置入00FC000
	write_2byte(0x803F);//write MSB of freq1 reg
	write_2byte(0xC000);//write phase0 reg
	write_2byte(0xF000);//write phase1 reg
	write_2byte(0x2000);//lect freq0,phase 0,28bit mode,rst=0
}
//输出指定频率
void output(unsigned long freq_value)
{
	unsigned long dds;//32 bit data for dds control word
	uint dds1,dds2;
	dds=freq_value*18.64135111111;
	dds=dds<<2;
	dds1=dds;	 //低字节
	dds2=dds>>16;  //高字节
	dds1=dds1>>2;
	dds2=dds2&0x7FFF;
	dds2=dds2|0x4000;
	write_2byte(0x2000);//enable the command mode is 28mode
	write_2byte(dds1);
	write_2byte(dds2);
}

void main()
{
	init_dds();
	output(1000000);
	while (1);
}