/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 2 $
 * $Date: 16/10/25 4:29p $
 * @brief    Show how to wake up system from Power-down mode by GPIO interrupt.
 * @note
 * Copyright (C) 2016 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC126.h"


#define PLLCTL_SETTING  CLK_PLLCTL_72MHz_HXT
#define PLL_CLOCK       72000000


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

    /* Enter to Power-down mode */
    CLK_PowerDown();
}

/**
 * @brief       PortA/PortB IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The PortA/PortB default IRQ, declared in startup_NUC126.s.
 */
void GPAB_IRQHandler(void)
{
    /* To check if PB.3 interrupt occurred */
    if(GPIO_GET_INT_FLAG(PB, BIT3))
    {
        GPIO_CLR_INT_FLAG(PB, BIT3);
        printf("PB.3 INT occurred.\n");
    }
    else
    {
        /* Un-expected interrupt. Just clear all PB interrupts */
        PB->INTSRC = PB->INTSRC;
        printf("Un-expected interrupts.\n");
    }
}

void SYS_Init(void)
{

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

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

    /* Wait for HIRC clock ready */
    CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);

    /* Select HCLK clock source as HIRC and HCLK source divider as 1 */
    CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));

    /* Enable HXT clock (external XTAL 12MHz) */
    CLK_EnableXtalRC(CLK_PWRCTL_HXTEN_Msk);

    /* Wait for HXT clock ready */
    CLK_WaitClockReady(CLK_STATUS_HXTSTB_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 as HXT and UART module clock divider as 1 */
    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UARTSEL_HXT, CLK_CLKDIV0_UART(1));

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

    /* Set PD multi-function pins for UART0 RXD(PD.0) and TXD(PD.1) */
    SYS->GPD_MFPL = (SYS->GPD_MFPL & (~SYS_GPD_MFPL_PD0MFP_Msk)) | SYS_GPD_MFPL_PD0MFP_UART0_RXD;
    SYS->GPD_MFPL = (SYS->GPD_MFPL & (~SYS_GPD_MFPL_PD1MFP_Msk)) | SYS_GPD_MFPL_PD1MFP_UART0_TXD;

}

void UART0_Init()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 */
    SYS_ResetModule(UART0_RST);

    /* Configure UART0 and set UART0 baud rate */
    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("|    GPIO Power-Down and Wake-up by PB.3 Sample Code    |\n");
    printf("+-------------------------------------------------------+\n\n");

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

    /* Enable interrupt de-bounce function and select de-bounce sampling cycle time is 1024 clocks of LIRC clock */
    GPIO_SET_DEBOUNCE_TIME(GPIO_DBCTL_DBCLKSRC_LIRC, GPIO_DBCTL_DBCLKSEL_1024);
    GPIO_ENABLE_DEBOUNCE(PB, BIT3);

    /* Unlock protected registers before entering Power-down mode */
    SYS_UnlockReg();

    /* Waiting for PB.3 rising-edge interrupt event */
    printf("Enter to Power-Down ......\n");

    /* Enter to Power-down mode */
    PowerDownFunction();

    printf("System waken-up done.\n\n");

    while(1);

}

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