/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 2 $
 * $Date: 16/10/25 4:27p $
 * @brief    Use RTC alarm interrupt event to wake up system.
 * @note
 * Copyright (C) 2016 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC126.h"


#define PLLCON_SETTING  CLK_PLLCTL_72MHz_HXT
#define PLL_CLOCK       72000000


/*---------------------------------------------------------------------------------------------------------*/
/* Global Interface Variables Declarations                                                                 */
/*---------------------------------------------------------------------------------------------------------*/
extern int IsDebugFifoEmpty(void);
volatile uint8_t g_u8IsRTCAlarmINT = 0;


/*---------------------------------------------------------------------------------------------------------*/
/*  Function for System Entry to Power Down Mode                                                           */
/*---------------------------------------------------------------------------------------------------------*/
void PowerDownFunction(void)
{
    printf("\nSystem enter to power-down mode ...\n\n");

    /* To check if all the debug messages are finished */
    while(IsDebugFifoEmpty() == 0);

    SCB->SCR = 4;

    /* To program PWRCTL register, it needs to disable register protection first. */
    CLK->PWRCTL &= ~(CLK_PWRCTL_PDEN_Msk);
    CLK->PWRCTL |= (CLK_PWRCTL_PDEN_Msk | CLK_PWRCTL_PDWKIEN_Msk);

    __WFI();
}

/**
 * @brief       IRQ Handler for RTC Interrupt
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The RTC_IRQHandler is default IRQ of RTC, declared in startup_NUC126.s.
 */
void RTC_IRQHandler(void)
{
    /* To check if RTC alarm interrupt occurred */
    if(RTC_GET_ALARM_INT_FLAG() == 1)
    {
        /* Clear RTC alarm interrupt flag */
        RTC_CLEAR_ALARM_INT_FLAG();

        g_u8IsRTCAlarmINT++;
    }
}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Enable HIRC clock */
    CLK->PWRCTL |= CLK_PWRCTL_HIRCEN_Msk;

    /* Waiting for HIRC clock ready */
    while(!(CLK->STATUS & CLK_STATUS_HIRCSTB_Msk));

    /* Switch HCLK clock source to HIRC */
    CLK->CLKSEL0 = CLK_CLKSEL0_HCLKSEL_HIRC;

    /* Set PLL to Power-down mode and PLLSTB bit in CLK_STATUS register will be cleared by hardware.*/
    CLK->PLLCTL |= CLK_PLLCTL_PD_Msk;

    /* Enable HXT and LXT-32KHz */
    CLK->PWRCTL |= CLK_PWRCTL_HXTEN_Msk | CLK_PWRCTL_LXTEN_Msk;

    /* Enable PLL and Set PLL frequency */
    CLK->PLLCTL = PLLCON_SETTING;

    /* Waiting for clock ready */
    while(!(CLK->STATUS & CLK_STATUS_PLLSTB_Msk));
    while(!(CLK->STATUS & CLK_STATUS_HXTSTB_Msk));
    while(!(CLK->STATUS & CLK_STATUS_LXTSTB_Msk));

    /* Switch STCLK source to HCLK/2 and HCLK clock source to PLL */
    CLK->CLKSEL0 = CLK_CLKSEL0_STCLKSEL_HCLK_DIV2 | CLK_CLKSEL0_HCLKSEL_PLL;

    /* Enable peripheral clock */
    CLK->APBCLK0 = CLK_APBCLK0_UART0CKEN_Msk | CLK_APBCLK0_RTCCKEN_Msk;

    /* Peripheral clock source */
    CLK->CLKSEL1 = CLK_CLKSEL1_UARTSEL_PLL;

    /* Update System Core Clock */
    /* User can use SystemCoreClockUpdate() to calculate PllClock, SystemCoreClock and CycylesPerUs automatically. */
    SystemCoreClockUpdate();

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set PD multi-function pins for UART0 RXD, TXD */
    SYS->GPD_MFPL &= ~(SYS_GPD_MFPL_PD0MFP_Msk | SYS_GPD_MFPL_PD1MFP_Msk);
    SYS->GPD_MFPL |= (SYS_GPD_MFPL_PD0MFP_UART0_RXD | SYS_GPD_MFPL_PD1MFP_UART0_TXD);
}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART module */
    SYS->IPRST1 |=  SYS_IPRST1_UART0RST_Msk;
    SYS->IPRST1 &= ~SYS_IPRST1_UART0RST_Msk;

    /* Configure UART0 and set UART0 Baudrate */
    UART0->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(PllClock, 115200);
    UART0->LINE = UART_WORD_LEN_8 | UART_PARITY_NONE | UART_STOP_BIT_1;
}

/*---------------------------------------------------------------------------------------------------------*/
/*  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 @ %dHz\n", SystemCoreClock);
    printf("+-------------------------------------+\n");
    printf("|    RTC Alarm Wake-up Sample Code    |\n");
    printf("+-------------------------------------+\n\n");

    /* Enable RTC NVIC */
    NVIC_EnableIRQ(RTC_IRQn);

    /* Initial RTC and stay in normal state */
    if(RTC->INIT != RTC_INIT_ACTIVE_Msk)
    {
        RTC->INIT = RTC_INIT_KEY;
        while(RTC->INIT != RTC_INIT_ACTIVE_Msk);
    }

    /* Setting RTC current date/time */
    RTC_WaitAccessEnable();
    RTC->CLKFMT  = RTC_CLOCK_24;
    RTC->WEEKDAY = RTC_SUNDAY;
    RTC->CAL     = 0x00160515;          /* Date: 2016/05/15 */
    RTC->TIME    = 0x00153030;          /* Time: 15:30:30 */

    /* Setting RTC alarm date/time and enable alarm interrupt */
    RTC->CALM  = 0x00160515;            /* Date: 2016/05/15 */
    RTC->TALM  = 0x00153035;            /* Time: 15:30:35 */
    RTC->INTEN = RTC_INTEN_ALMIEN_Msk;

    printf("# Set RTC current date/time: 2016/05/15 15:30:30.\n");
    printf("# Set RTC alarm date/time:   2016/05/15 15:30:35.\n");
    printf("# Wait system waken-up by RTC alarm interrupt event.\n");

    g_u8IsRTCAlarmINT = 0;

    /* System enter to Power-down */
    /* To program PWRCTL register, it needs to disable register protection first. */
    SYS_UnlockReg();
    PowerDownFunction();

    while(g_u8IsRTCAlarmINT == 0);

    /* Read current RTC date/time */
    printf("System has been waken-up and current date/time is:\n");
    printf("    20%02x/%02x/%02x %02x:%02x:%02x\n",
           (RTC->CAL >> RTC_CAL_YEAR_Pos) & 0xFF, (RTC->CAL >> RTC_CAL_MON_Pos) & 0xFF, (RTC->CAL >> RTC_CAL_DAY_Pos) & 0xFF,
           (RTC->TIME >> RTC_TIME_HR_Pos) & 0xFF, (RTC->TIME >> RTC_TIME_MIN_Pos) & 0xFF, (RTC->TIME >> RTC_TIME_SEC_Pos) & 0xFF);

    while(1);
}

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