/**************************************************************************//**
 * @file     main.c
 * @version  V2.00
 * $Revision: 7 $
 * $Date: 15/09/14 4:29p $
 * @brief    Implement periodic WDT time-out interrupt event.
 * @note
 * Copyright (C) 2013 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC131.h"

#define PLL_CLOCK           50000000


/*---------------------------------------------------------------------------------------------------------*/
/* Global Interface Variables Declarations                                                                 */
/*---------------------------------------------------------------------------------------------------------*/
volatile uint8_t g_u8IsWDTTimeoutINT = 0;


/**
 * @brief       IRQ Handler for WDT and WWDT Interrupt
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The WDT_IRQHandler is default IRQ of WDT and WWDT, declared in startup_NUC131.s.
 */
void WDT_IRQHandler(void)
{
    if(WDT_GET_TIMEOUT_INT_FLAG() == 1)
    {
        /* Clear WDT time-out interrupt flag */
        WDT_CLEAR_TIMEOUT_INT_FLAG();

        g_u8IsWDTTimeoutINT = 1;
    }
}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Enable HIRC clock */
    CLK_EnableXtalRC(CLK_PWRCON_IRC22M_EN_Msk);

    /* Waiting for HIRC clock ready */
    CLK_WaitClockReady(CLK_CLKSTATUS_IRC22M_STB_Msk);

    /* Switch HCLK clock source to HIRC */
    CLK_SetHCLK(CLK_CLKSEL0_HCLK_S_HIRC, CLK_CLKDIV_HCLK(1));

    /* Enable HXT and LIRC */
    CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk | CLK_PWRCON_IRC10K_EN_Msk);

    /* Waiting for clock ready */
    CLK_WaitClockReady(CLK_CLKSTATUS_XTL12M_STB_Msk | CLK_CLKSTATUS_IRC10K_STB_Msk);

    /* Set core clock as PLL_CLOCK from PLL and SysTick source to HCLK/2*/
    CLK_SetCoreClock(PLL_CLOCK);
    CLK_SetSysTickClockSrc(CLK_CLKSEL0_STCLK_S_HCLK_DIV2);

    /* Enable peripheral clock */
    CLK_EnableModuleClock(UART0_MODULE);
    CLK_EnableModuleClock(WDT_MODULE);

    /* Peripheral clock source */
    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_PLL, CLK_CLKDIV_UART(1));
    CLK_SetModuleClock(WDT_MODULE, CLK_CLKSEL1_WDT_S_LIRC, 0);

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set PB multi-function pins for UART0 RXD, TXD */
    SYS->GPB_MFP &= ~(SYS_GPB_MFP_PB0_Msk | SYS_GPB_MFP_PB1_Msk);
    SYS->GPB_MFP |= (SYS_GPB_MFP_PB0_UART0_RXD | SYS_GPB_MFP_PB1_UART0_TXD);
}

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

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

/*---------------------------------------------------------------------------------------------------------*/
/*  MAIN function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int main(void)
{
    uint32_t u32IntCnts = 0;

    /* 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("CPU @ %d Hz\n", SystemCoreClock);
    printf("+------------------------------------------+\n");
    printf("|    WDT Time-out Interrupt Sample Code    |\n");
    printf("+------------------------------------------+\n\n");

    printf("# WDT Settings:\n");
    printf("    - Clock source is 10 kHz                \n");
    printf("    - Time-out interval is 2^14 * WDT clock \n");
    printf("      (around 1.6384 second)                \n");
    printf("    - Interrupt enable                      \n");
    printf("# System will generate a WDT time-out interrupt event after around 1.6384 second.\n");
    printf("    (Use PA.0 high/low period time to check WDT time-out interval)\n\n");

    /* Use PA.0 to check time-out period time */
    GPIO_SetMode(PA, BIT0, GPIO_PMD_OUTPUT);
    PA0 = 1;
    PA0 = 0;

    /* Because of all bits can be written in WDT Control Register are write-protected;
       To program it needs to disable register protection first. */
    SYS_UnlockReg();

    /* Select WDT time-out interval to 2^14 * WDT clock then start WDT counting */
    g_u8IsWDTTimeoutINT = 0;
    WDT_Open(WDT_TIMEOUT_2POW14, 0, FALSE, FALSE);

    /* Enable WDT interrupt function */
    WDT_EnableInt();

    /* Enable WDT NVIC */
    NVIC_EnableIRQ(WDT_IRQn);

    while(1)
    {
        /* Check if WDT time-out interrupt occurred or not */
        while(g_u8IsWDTTimeoutINT == 0);

        g_u8IsWDTTimeoutINT = 0;
        PA0 ^= 1;

        printf("WDT time-out interrupt occurred. INT counts: %d      \r", ++u32IntCnts);
    }
}

/*** (C) COPYRIGHT 2013 Nuvoton Technology Corp. ***/
