MSP430控制AD9850产生频率可调的方波及正弦波

/***************************** code name : AD9850 code function : the code is used to control the AD9850 with msp430. DDS Frequency : under 45MHz( 125Mhz XTAL ) coder : Du Li, David Pei fisrt code date : 09-8-4 last updated : 09-8-6 *******************************/ /************pin definition******** P2.0(pin 80) -->D7(pin 25) P2.1(pin 79) W_CLK(pin 7) P2.2(pin 78) FQ_UD(pin 8) P2.3(pin 77) RESET(pin 22) **********************************/ #include "msp430x44x.h" #define dat BIT0; #define clk BIT1; #define update BIT2; #define rst BIT3; //RESET FUNCTION void reset(); //DELAY FUNCTION void delay(int i); //SET THE FREQUENCY void set_fq(unsigned long fq); void main() { unsigned long feq,i; WDTCTL = WDTPW + WDTHOLD; P2SEL=0; P2DIR=0xFF; P2OUT=0; for(i=0;i<20;i++) { reset(); } feq= 10* 34359738.37; //set frequency to 10MHz; while(1) { set_fq(feq); } }; void reset() { P2OUT|=rst; delay(10); P2OUT^=rst; _NOP(); } void set_fq(unsigned long fq) { unsigned char FqWord[5]; int i,j; //set the 32bit tuning word(frequency control word) FqWord[0]=(fq & 0x000000ff); //7~0 FqWord[1]=(fq & 0x0000ff00)>>8; //15~8 FqWord[2]=(fq & 0x00ff0000)>>16; //23~16 FqWord[3]=(fq & 0xff000000)>>24; //31~24 FqWord[4]=0; //39~32 //load P2OUT &= ~update; for(i=0;i<5;i++) { unsigned char tmp=0x00000001; for(j=0;j<8;j++) { if( ( FqWord[i] & tmp ) == tmp ) //load each bit seperately { P2OUT |= dat; } else { P2OUT &= ~dat; } _NOP(); P2OUT |= clk; _NOP(); P2OUT &= ~clk; _NOP(); tmp=tmp<<1; } } P2OUT |= update; delay(10); P2OUT = 0x00; } void delay(int i) { for(;i-->0;); }