/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 7 $
 * $Date: 15/07/02 11:18a $
 * @brief    Demonstrate how to wake-up form Power-down mode by GPIO interrupt.
 * @note
 * Copyright (C) 2014~2015 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC123.h"


#define HCLK_CLOCK           72000000


/*---------------------------------------------------------------------------------------------------------*/
/*  Function for System Entry to Power Down Mode                                                           */
/*---------------------------------------------------------------------------------------------------------*/
void PowerDownFunction(void)
{
    /* To check if all the debug messages are finished */
    UART_WAIT_TX_EMPTY(UART0);

    SCB->SCR = 4;

    CLK->PWRCON = (CLK->PWRCON & ~(CLK_PWRCON_PWR_DOWN_EN_Msk | CLK_PWRCON_PD_WAIT_CPU_Msk)) | CLK_PWRCON_PD_WAIT_CPU_Msk;

    CLK->PWRCON |= CLK_PWRCON_PWR_DOWN_EN_Msk;

    __WFI();
}

/**
 * @brief       GPIO PA/PB IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The PA/PB default IRQ, declared in startup_NUC123Series.s.
 */
void GPAB_IRQHandler(void)
{
    /* To check if PB.5 interrupt occurred */
    if(GPIO_GET_INT_FLAG(PB, BIT5))
    {
        GPIO_CLR_INT_FLAG(PB, BIT5);
        printf("PB.5 INT occurred.\n");
    }
    else
    {
        /* Un-expected interrupt. Just clear all PA and PB interrupts */
        PA->ISRC = PA->ISRC;
        PB->ISRC = PB->ISRC;
        printf("Un-expected interrupts.\n");
    }
}

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

    /* Enable XT1_OUT(PF0) and XT1_IN(PF1) */
    SYS->GPF_MFP &= ~(SYS_GPF_MFP_PF0_Msk | SYS_GPF_MFP_PF1_Msk);
    SYS->GPF_MFP |= SYS_GPF_MFP_PF0_XT1_OUT | SYS_GPF_MFP_PF1_XT1_IN;

    /* Enable Internal RC 22.1184MHz clock */
    CLK_EnableXtalRC(CLK_PWRCON_OSC22M_EN_Msk);

    /* Waiting for Internal RC 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 XTAL 12MHz clock */
    CLK_EnableXtalRC(CLK_PWRCON_XTL12M_EN_Msk);

    /* Waiting for external XTAL clock ready */
    CLK_WaitClockReady(CLK_CLKSTATUS_XTL12M_STB_Msk);

    /* Set core clock as HCLK_CLOCK */
    CLK_SetCoreClock(HCLK_CLOCK);

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

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

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Set GPB multi-function pins for UART0 RXD(PB.0) and TXD(PB.1) */
    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()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 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();

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

    printf("\n\nCPU @ %d Hz\n", SystemCoreClock);
    printf("+-------------------------------------------------------+\n");
    printf("|    GPIO Power-Down and Wake-up by PB.5 Sample Code    |\n");
    printf("+-------------------------------------------------------+\n\n");

    /* Configure PB.5 as Input mode and enable interrupt by rising edge trigger */
    GPIO_SetMode(PB, BIT5, GPIO_PMD_INPUT);
    GPIO_EnableInt(PB, 5, GPIO_INT_RISING);
    NVIC_EnableIRQ(GPAB_IRQn);

    /* Waiting for PB.5 rising-edge interrupt event */
    while(1)
    {
        printf("Enter to Power-Down ......\n");
        PowerDownFunction();
        UART_WAIT_TX_EMPTY(UART0);
        printf("System waken-up done.\n\n");
    }

}

/*** (C) COPYRIGHT 2014~2015 Nuvoton Technology Corp. ***/
