/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 4 $
 * $Date: 15/05/22 2:52p $
 * @brief    Show how to wake up system from Power-down mode by GPIO interrupt.
 *
 * @note
 * Copyright (C) 2013 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "M051Series.h"


#define PLL_CLOCK           50000000


/*---------------------------------------------------------------------------------------------------------*/
/*  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_PD_WU_INT_EN_Msk;
    CLK->PWRCON |= CLK_PWRCON_PWR_DOWN_EN_Msk;

    __WFI();
}

/**
 * @brief       Port0/Port1 IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The Port0/Port1 default IRQ, declared in startup_M051Series.s.
 */
void GPIOP0P1_IRQHandler(void)
{
    /* To check if P1.3 interrupt occurred */
    if(GPIO_GET_INT_FLAG(P1, BIT3))
    {
        GPIO_CLR_INT_FLAG(P1, BIT3);
        printf("P1.3 INT occurred.\n");
    }
    else
    {
        /* Un-expected interrupt. Just clear all PORT0, PORT1 interrupts */
        P0->ISRC = P0->ISRC;
        P1->ISRC = P1->ISRC;
        printf("Un-expected interrupts.\n");
    }
}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/
    /* 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 PLL_CLOCK from PLL */
    CLK_SetCoreClock(PLL_CLOCK);

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

    /* Select UART module clock source */
    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART_S_PLL, CLK_CLKDIV_UART(1));

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

    /* Set P3 multi-function pins for UART0 RXD and TXD */
    SYS->P3_MFP &= ~(SYS_MFP_P30_Msk | SYS_MFP_P31_Msk);
    SYS->P3_MFP |= (SYS_MFP_P30_RXD0 | SYS_MFP_P31_TXD0);

}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 */
    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 P1.3 Sample Code    |\n");
    printf("+-------------------------------------------------------+\n\n");

    /* Configure P1.3 as Input mode and enable interrupt by rising edge trigger */
    GPIO_SetMode(P1, BIT3, GPIO_PMD_INPUT);
    GPIO_EnableInt(P1, 3, GPIO_INT_RISING);
    NVIC_EnableIRQ(GPIO_P0P1_IRQn);

    /* Waiting for P1.3 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 2013 Nuvoton Technology Corp. ***/
