[技术问答] Mini58

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

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

 * [url=home.php?mod=space&uid=895143]@version[/url]  V1.00

 * $Revision: 3 $

 * $Date: 15/05/28 10:37a $

 * [url=home.php?mod=space&uid=247401]@brief[/url]    Use the timer pin P3.2 to demonstrate timer trigger counting mode

 *           function. And displays the measured input frequency to UART console.

 *

 * @note

 * Copyright (C) 2015 Nuvoton Technology Corp. All rights reserved.

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

#include <stdio.h>

#include "Mini58Series.h"





void TMR0_IRQHandler(void)

{

    uint32_t t = TIMER_GetCaptureData(TIMER0);



    // Timer clock source us 22.1184M

    printf("Input frequency is %dHz\n", 22118400 / t);

    TIMER_ClearCaptureIntFlag(TIMER0);



}





void SYS_Init(void)

{

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

    /* Init System Clock                                                                                       */

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



    /* Unlock protected registers */

    SYS_UnlockReg();



    /* Set P5 multi-function pins for XTAL1 and XTAL2 */

    SYS->P5_MFP &= ~(SYS_MFP_P50_Msk | SYS_MFP_P51_Msk);

    SYS->P5_MFP |= (SYS_MFP_P50_XT1_IN | SYS_MFP_P51_XT1_OUT);



    /* Enable external 12MHz XTAL (UART), and HIRC */

    CLK->PWRCTL = CLK_PWRCTL_XTL12M | CLK_PWRCTL_HIRCEN_Msk;



    /* Waiting for clock ready */

    CLK_WaitClockReady(CLK_STATUS_XTLSTB_Msk | CLK_STATUS_HIRCSTB_Msk);



    /* Enable UART and Timer 0 clock */

    CLK->APBCLK = CLK_APBCLK_UART0CKEN_Msk | CLK_APBCLK_TMR0CKEN_Msk;



    /* Select UART clock source from external crystal*/

    CLK->CLKSEL1 = (CLK->CLKSEL1 & ~CLK_CLKSEL1_UARTSEL_Msk) | CLK_CLKSEL1_UARTSEL_XTAL;



    /* Update System Core Clock */

    /* User can use SystemCoreClockUpdate() to calculate SystemCoreClock and CycylesPerUs automatically. */

    SystemCoreClockUpdate();





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

    /* Init I/O Multi-function                                                                                 */

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

    /* Set P1 multi-function pins for UART RXD, TXD */

    SYS->P1_MFP = SYS_MFP_P12_UART0_RXD | SYS_MFP_P13_UART0_TXD;



    /* Set P3 multi function pin for Timer 0 capture pin */

    SYS->P3_MFP = SYS_MFP_P32_TM0_EXT;



    /* Lock protected registers */

    SYS_LockReg();

}



int main(void)

{

    int volatile i;



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

       In the end of SYS_Init() will issue SYS_LockReg()

       to lock protected register. If user want to write

       protected register, please issue SYS_UnlockReg()

       to unlock protected register if necessary */

    SYS_Init();



    /* Init UART to 115200-8n1 for print message */

    UART_Open(UART0, 115200);



    printf("\nThis sample code demonstrate timer trigger counting mode.\n");

    printf("Please connect input source with Timer 0 capture pin T0EX (P3.2), press any key to continue\n");

    getchar();



    // Give a dummy target frequency here. Will over write capture resolution with macro

    TIMER_Open(TIMER0, TIMER_PERIODIC_MODE, 1000000);



    // Update prescale to set proper resolution.

    TIMER_SET_PRESCALE_VALUE(TIMER0, 0);



    // Set compare value as large as possible, so don't need to worry about counter overrun too frequently.

    TIMER_SET_CMP_VALUE(TIMER0, 0xFFFFFF);



    // Configure Timer 0 free counting mode, capture TDR value on rising edge

    TIMER_EnableCapture(TIMER0, TIMER_CAPTURE_TRIGGER_COUNTING_MODE, TIMER_CAPTURE_RISING_EDGE);



    // Start Timer 0

    TIMER_Start(TIMER0);



    // Enable timer interrupt

    TIMER_EnableCaptureInt(TIMER0);

    NVIC_EnableIRQ(TMR0_IRQn);



    while(1);



}



/*** (C) COPYRIGHT 2015 Nuvoton Technology Corp. ***/