/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 5 $
 * $Date: 17/05/04 12:58p $
 * @brief    Change duty cycle and period of output waveform in PWM down count type.
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 * @copyright Copyright (C) 2016 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "M0564.h"


#define PLL_CLOCK       72000000

volatile uint32_t gu32Period;

/**
 * @brief       Timer0 IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The Timer0 default IRQ, declared in startup_M0564.s.
 */
void TMR0_IRQHandler(void)
{
    static uint32_t u32Toggle = 0;

    if(TPWM_GET_PERIOD_INT_FLAG(TIMER0))
    {
        if(u32Toggle == 0)
        {
            /* Set PWM period to generate output frequency 36000 Hz */
            TPWM_SET_PERIOD(TIMER0, ((gu32Period / 2) - 1));

            /* Set PWM duty, 40% */
            TPWM_SET_CMPDAT(TIMER0, (((gu32Period / 2) * 4) / 10));
        }
        else
        {
            /* Set PWM period to generate output frequency 18000 Hz */
            TPWM_SET_PERIOD(TIMER0, (gu32Period - 1));

            /* Set PWM duty, 50% */
            TPWM_SET_CMPDAT(TIMER0, (gu32Period / 2));
        }
        u32Toggle ^= 1;
        TPWM_CLEAR_PERIOD_INT_FLAG(TIMER0);
    }
}

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(PLL_CLOCK);
    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_UARTSEL_PLL, CLK_CLKDIV0_UART(1));
    CLK_SetModuleClock(TMR0_MODULE, CLK_CLKSEL1_TMR0SEL_PCLK0, 0);

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set PD multi-function pins for UART0 RXD and TXD */
    SYS->GPD_MFPL &= ~(SYS_GPD_MFPL_PD0MFP_Msk | SYS_GPD_MFPL_PD1MFP_Msk);
    SYS->GPD_MFPL |= (SYS_GPD_MFPL_PD0MFP_UART0_RXD | SYS_GPD_MFPL_PD1MFP_UART0_TXD);

    /* Set Timer0 PWM CH0(TM0) pin */
    SYS->GPD_MFPL &= ~SYS_GPD_MFPL_PD4MFP_Msk;
    SYS->GPD_MFPL |= SYS_GPD_MFPL_PD4MFP_TM0;
}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART module */
    SYS_ResetModule(UART0_RST);

    /* Configure UART0 and set UART0 Baudrate */
    UART_Open(UART0, 115200);
}

/*---------------------------------------------------------------------------------------------------------*/
/*  MAIN function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int main(void)
{
    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Init System, peripheral clock and multi-function I/O */
    SYS_Init();

    /* Lock protected registers */
    SYS_LockReg();

    /* Init UART0 for printf */
    UART0_Init();

    printf("\n\nCPU @ %d Hz\n", SystemCoreClock);
    printf("+-----------------------------------------------+\n");
    printf("|    Timer PWM Change Duty Cycle Sample Code    |\n");
    printf("+-----------------------------------------------+\n\n");

    printf("# Timer0 PWM_CH0 frequency of first period is 18 kHz and duty is 50%%.\n");
    printf("# Timer0 PWM_CH0 frequency of second period is 36 kHz and duty is 40%%.\n");
    printf("# I/O configuration:\n");
    printf("    - Timer0 PWM_CH0 on PD.4\n\n");
    printf("        Timer0 PWM_CH0 waveform of this sample shown below: \n");
    printf("\n");
    printf("        |<-        PERIOD0+1        ->|                     \n");
    printf("                       |<-   CMP0   ->|                     \n");
    printf("                                      |<-  PERIOD1+1 ->|    \n");
    printf("                                               |<CMP1 >|    \n");
    printf("      __                ______________          _______                             \n");
    printf("        |______50%%_____|     50%%      |___60%%__|  40%%  |___ PWM_CH0 outut duty  \n");
    printf("\n");

    /* Change Timer to PWM counter mode */
    TPWM_ENABLE_PWM_MODE(TIMER0);

    /* Set PWM mode as independent mode*/
    TPWM_ENABLE_INDEPENDENT_MODE(TIMER0);

    /* Set Timer0 PWM output frequency is 18000 Hz, duty 50% in up count type */
    TPWM_ConfigOutputFreqAndDuty(TIMER0, 18000, 50);

    /* Get initial period and comparator value */
    gu32Period = TPWM_GET_PERIOD(TIMER0) + 1;

    /* Set PWM down count type */
    TPWM_SET_COUNTER_TYPE(TIMER0, TPWM_DOWN_COUNT);

    /* Enable output of PWM_CH0 */
    TPWM_ENABLE_OUTPUT(TIMER0, TPWM_CH0);

    /* Enable period event interrupt */
    TPWM_ENABLE_PERIOD_INT(TIMER0);
    NVIC_EnableIRQ(TMR0_IRQn);

    /* Start Timer PWM counter */
    TPWM_START_COUNTER(TIMER0);

    printf("*** Check Timer0 PWM_CH0 output waveform by oscilloscope ***\n");

    while(1);
}

/*** (C) COPYRIGHT 2016 Nuvoton Technology Corp. ***/
