M451的DSP内核FFT应用

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

 * [url=home.php?mod=space&uid=288409]@file[/url]     main.c

 * [url=home.php?mod=space&uid=895143]@version[/url]  V1.0

 * $Date: 16/09/22 10:04a $

 * @brief

 *         Display how to use DSP FFT function

 *                     

 * @note

 * Copyright (C) 2016 Nuvoton Technology Corp. All rights reserved.

 *

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

#include <stdio.h>

#include "M451Series.h" 

#include "arm_math.h" 



#define TEST_LENGTH_SAMPLES 2048 //Must be fftsize*2

 

/* ------------------------------------------------------------------- 

* External Input and Output buffer Declarations for FFT Bin Example 

* ------------------------------------------------------------------- */ 

extern float32_t testInput_f32_10khz[TEST_LENGTH_SAMPLES]; 

static float32_t testOutput[TEST_LENGTH_SAMPLES/2]; 



/* ------------------------------------------------------------------ 

* Global variables for FFT Bin Example 

* ------------------------------------------------------------------- */ 

uint32_t fftSize = 1024; 

uint32_t ifftFlag = 0; 

uint32_t doBitReverse = 1; 

/* Reference index at which max energy of bin ocuurs */ 

uint32_t refIndex = 213, testIndex = 0; 

arm_cfft_radix4_instance_f32 S; 

float32_t maxValue,Mainfreq; 

int CalTime;

void SYS_Init(void)

{

           /*---------------------------------------------------------------------------------------------------------*/

    /* Init System Clock                                                                                       */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable HIRC clock */

    CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);



    /* Waiting for HIRC clock ready */

    CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);



    /* Switch HCLK clock source to HIRC */

    CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));



    /* Enable HXT */

    CLK_EnableXtalRC(CLK_PWRCTL_HXTEN_Msk);



    /* Waiting for clock ready */

    CLK_WaitClockReady(CLK_STATUS_HXTSTB_Msk);



    /* Set core clock as PLL_CLOCK from PLL and SysTick source to HCLK/2*/

    CLK_SetCoreClock(72000000);

    CLK_SetSysTickClockSrc(CLK_CLKSEL0_STCLKSEL_HCLK_DIV2);



    /* Enable peripheral clock */

    CLK_EnableModuleClock(UART0_MODULE);

    CLK_EnableModuleClock(TMR0_MODULE);



    /* Peripheral clock source */

    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_TMR0SEL_HXT, CLK_CLKDIV0_UART(1));

    CLK_SetModuleClock(TMR0_MODULE, CLK_CLKSEL1_TMR0SEL_HXT, 0);



}



void UART_Init(void)

{

    /* Set PD multi-function pins for UART0 RXD and TXD */

    SYS->GPD_MFPL = SYS_GPD_MFPL_PD0MFP_UART0_RXD | SYS_GPD_MFPL_PD1MFP_UART0_TXD;

    /* Reset UART module */

    SYS_ResetModule(UART0_RST);



    /* Configure UART0 and set UART0 Baudrate */

    UART_Open(UART0, 115200);

}



/*---------------------------------------------------------------------------------------------------------*/

/*  Main Function                                                                                          */

/*---------------------------------------------------------------------------------------------------------*/

int32_t main(void)

{

        /* Unlock protected registers */

    SYS_UnlockReg();



    /* Init System, peripheral clock and multi-function I/O */

    SYS_Init();



    /* Lock protected registers */

    SYS_LockReg();



    /* Init UART for printf */

    UART_Init();



                /* Measure FFT calcultion time */

                TIMER_Open(TIMER0, TIMER_CONTINUOUS_MODE, 1);

                TIMER_Start(TIMER0);

         

                /* Initialize the CFFT/CIFFT module */  

                arm_cfft_radix4_init_f32(&S, fftSize,ifftFlag, doBitReverse); 

        

                /* Process the data through the CFFT/CIFFT module */ 

                arm_cfft_radix4_f32(&S, testInput_f32_10khz); 

                TIMER_Close(TIMER0);

                /* Process the data through the Complex Magnitude Module for calculating the magnitude at each bin */ 

                arm_cmplx_mag_f32(testInput_f32_10khz, testOutput,fftSize/2);  



                /* Calculates maxValue and returns corresponding BIN value */ 

                arm_max_f32(testOutput, fftSize/2, &maxValue, &testIndex); 



                CalTime=TIMER_GetCounter(TIMER0);



                /* Mainfreq=testindex*sample rate/fftsize */

                Mainfreq=testIndex*5000/fftSize;

                

                printf("Main frequency is %f\n",Mainfreq);

                printf("time is %d \n",CalTime); 

         

    while(1);      

         

}