TMS320F2812_FFT源码..docVIP

TMS320F2812 FFT源码(包括详细的应用文档) /* Fast Fourier Transform (FFT). Using 8 points, takes about 1.2 ms to execute one FFT. Sets up General Purpose Timer 1 to generate events at 10 kHz. Will produce 10 kHz output on T1PWM and T1PWM pins. */ #include system.h #include eva.h #include io2407.h #include adc.h #include interrup.h #include fftcmplx.h /* Complex structure definition*/ extern void FFT(COMPLEX *Y, int N); /* FFT Function */ /* The following define gives the number of samples. */ /* It should divide exactly into 512 */ /* Should N be increased, to say to 32, then the execution */ /* time of the FFT would increase */ #define N 8 unsigned int perform_fft = 0; /* Flag driven by interrupt */ /*************************************************************/ /* Initialise General Purpose Timers GPT1 and GPT2 */ /*************************************************************/ /* Initialise General Purpose Timer 1. */ void init_GPT1(void) { MCRA |= T1PWM; /* Turn on T1PWM */ T1CON = 0x8142; /* Turn off GPT1 */ GPTCONA = 0x0041; /* Active low. */ T1PR = 1475; /* Sample at 10 kHz */ T1CMPR = 0; /* Duty = 0% */ T1CNT = 0xFFFE; /* Set to -2 */ T1CON = 0x9142; /* Start timer 1 */ EVAIFRA = 0xFFFF; /* Clear any pending interrupts */ EVAIMRA |= T1PINT_FLAG; /* Enable T1 period interrupt */ } /* Initialise General Purpose Timer 2 */ void init_GPT2(void) { MCRA |= T2PWM; /* Turn on T2PWM */ T2CON = 0x8142; /* Turn off GPT2 */ GPTCONA |= 0x0008; /* Controlled from GPT1 */ T2PR = 1475; /* Sample at 10 kHz */ T2CMPR = 0; /* Duty cycle 0% decimal */ T2CNT = 0xFFFE; /* Set to -2 */ T2CON = 0x9142; /* Start timer 2 */ } /**************************************************************/ void init_ADC() { /* Non Cascade for 8 measurements. */ /* Will affect RESULT0 to RESULT7 only */ ADCCTRL1 = (ADC_SOFT | ADC_CPS /*| ADC_ACQ_PS3 | ADC_ACQ_PS2*/ ); CHSELSEQ1 = 0x3210; /* 8 measurements 0 */ CHSELSEQ2 = 0x0000;