/**************************************************************************//**
 * @file     main.c
 * @version  V1.00
 * $Revision: 3 $
 * $Date: 15/02/06 10:22a $
 * @brief    Change duty cycle and period of output waveform by PWM Double Buffer function.
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 *
 * @copyright Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "M058S.h"

/*---------------------------------------------------------------------------------------------------------*/
/* Macro, type and constant definitions                                                                    */
/*---------------------------------------------------------------------------------------------------------*/

#define PLL_CLOCK           50000000


/*---------------------------------------------------------------------------------------------------------*/
/* Global variables                                                                                        */
/*---------------------------------------------------------------------------------------------------------*/

/**
 * @brief       PWMA IRQ Handler
 *
 * @param       None
 *
 * @return      None
 *
 * @details     ISR to handle PWMA interrupt event
 */
void PWMA_IRQHandler(void)
{
    static int toggle = 0;

    /* Update PWMA channel 0 period and duty */
    if(toggle == 0)
    {
        PWM_SET_CNR(PWMA, PWM_CH0, 99);
        PWM_SET_CMR(PWMA, PWM_CH0, 39);
    }
    else
    {
        PWM_SET_CNR(PWMA, PWM_CH0, 199);
        PWM_SET_CMR(PWMA, PWM_CH0, 99);
    }
    toggle ^= 1;
    /* Clear channel 0 period interrupt flag */
    PWM_ClearPeriodIntFlag(PWMA, 0);
}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable Internal RC clock */
    CLK_EnableXtalRC(CLK_PWRCON_OSC22M_EN_Msk);

    /* Waiting for IRC22M clock ready */
    CLK_WaitClockReady(CLK_CLKSTATUS_OSC22M_STB_Msk);

    /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
    CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_HIRC, CLK_CLKDIV_HCLK(1));

    /* Enable external 12MHz XTAL, internal 22.1184MHz */
    CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk | CLK_PWRCON_OSC22M_EN_Msk);

    /* Enable PLL and Set PLL frequency */
    CLK_SetCoreClock(PLL_CLOCK);

    /* Waiting for clock ready */
    CLK_WaitClockReady(CLK_CLKSTATUS_PLL_STB_Msk | CLK_CLKSTATUS_XTL12M_STB_Msk | CLK_CLKSTATUS_OSC22M_STB_Msk);

    /* Switch HCLK clock source to PLL */
    CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_PLL, CLK_CLKDIV_HCLK(2));

    /* Enable UART module clock */
    CLK_EnableModuleClock(UART0_MODULE);

    /* Enable PWM module clock */
    CLK_EnableModuleClock(PWM01_MODULE);
    CLK_EnableModuleClock(PWM23_MODULE);

    /* Select UART module clock source */
    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_HXT, CLK_CLKDIV_UART(1));

    /* Select PWM module clock source */
    CLK_SetModuleClock(PWM01_MODULE, CLK_CLKSEL1_PWM01_S_HXT, 0);
    CLK_SetModuleClock(PWM23_MODULE, CLK_CLKSEL1_PWM23_S_HXT, 0);

    /* Reset PWMA channel0~channel3 */
    SYS_ResetModule(PWM03_RST);

    /* Update System Core Clock */
    SystemCoreClockUpdate();

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set P3 multi-function pins for UART RXD and TXD  */
    SYS->P3_MFP &= ~(SYS_MFP_P30_Msk | SYS_MFP_P31_Msk);
    SYS->P3_MFP |= (SYS_MFP_P30_RXD | SYS_MFP_P31_TXD);
    /* Set P2 multi-function pins for PWMA Channel0~3 */
		SYS->P2_MFP &= ~(SYS_MFP_P20_Msk | SYS_MFP_P21_Msk | SYS_MFP_P22_Msk | SYS_MFP_P23_Msk);
    SYS->P2_MFP |= (SYS_MFP_P20_PWM0 | SYS_MFP_P21_PWM1 | SYS_MFP_P22_PWM2 | SYS_MFP_P23_PWM3);
}

/*---------------------------------------------------------------------------------------------------------*/
/*  Main Function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
    /* 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 */

    /* Unlock protected registers */
    SYS_UnlockReg();

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

    /* Lock protected registers */
    SYS_LockReg();

    /* Init UART to 115200-8n1 for print message */
    UART_Open(UART0, 115200);
    printf("+------------------------------------------------------------------------+\n");
    printf("|                          PWM Driver Sample Code                        |\n");
    printf("|                                                                        |\n");
    printf("+------------------------------------------------------------------------+\n");
    printf("  This sample code will use PWMA channel 0 to output waveform\n");
    printf("  I/O configuration:\n");
    printf("    waveform output pin: PWM0(P2.0)\n");
    printf("\nUse double buffer feature.\n");

    /*
        PWMA channel 0 waveform of this sample shown below:

        |<-        CNR + 1  clk     ->|  CNR + 1 = 199 + 1 CLKs
                       |<-CMR+1 clk ->|  CMR + 1 = 99 + 1 CLKs
                                      |<-   CNR + 1  ->|  CNR + 1 = 99 + 1 CLKs
                                               |<CMR+1>|  CMR + 1 = 39 + 1 CLKs
      __                ______________          _______
        |______100_____|     100      |____60__|   40  |_____PWM waveform

    */

    /*
      Configure PWMA channel 0 init period and duty.
      Period is __HXT / (prescaler * clock divider * (CNR + 1))
      Duty ratio = (CMR + 1) / (CNR + 1)
      Period = 12 MHz / (2 * 1 * (199 + 1)) =  30000 Hz
      Duty ratio = (99 + 1) / (199 + 1) = 50%
    */
    /* set PWMA channel 0 output configuration */
    PWM_ConfigOutputChannel(PWMA, PWM_CH0, 30000, 50);

    /* Enable PWM Output path for PWMA channel 0 */
    PWM_EnableOutput(PWMA, 0x1);

    /* Enable PWM channel 0 period interrupt */
    PWMA->PIER = PWM_PIER_PWMIE0_Msk;
    NVIC_EnableIRQ(PWMA_IRQn);

    /* Start */
    PWM_Start(PWMA, 0x1);

    while(1);

}




