/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 2 $
 * $Date: 16/10/25 4:26p $
 * @brief    Show the usage of GPIO external interrupt function and de-bounce function.
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 * @copyright 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


/**
 * @brief       External INT0/2/4 IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The External INT0/2/4 default IRQ, declared in startup_NUC126.s.
 */
void EINT024_IRQHandler(void)
{
    /* For PD.2, clear the INT flag */
    GPIO_CLR_INT_FLAG(PD, BIT2);

    printf("PD.2 EINT0 occurred.\n");
}

/**
 * @brief       External INT1/3/5 IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The External INT1/3/5 default IRQ, declared in startup_NUC126.s.
 */
void EINT135_IRQHandler(void)
{
    /* For PD.3, clear the INT flag */
    GPIO_CLR_INT_FLAG(PD, BIT3);

    printf("PD.3 EINT1 occurred.\n");
}

void SYS_Init(void)
{
	uint32_t u32TimeOutCnt;


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

    /* Enable HIRC clock (Internal RC 22.1184MHz) */
    CLK->PWRCTL |= CLK_PWRCTL_HIRCEN_Msk;

    /* Wait for HIRC clock ready */
    u32TimeOutCnt = __HIRC;
    while(!(CLK->STATUS & CLK_STATUS_HIRCSTB_Msk))
		if(--u32TimeOutCnt == 0) break;

    /* Select HCLK clock source as HIRC and HCLK clock divider as 1 */
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLKSEL_Msk)) | CLK_CLKSEL0_HCLKSEL_HIRC;
    CLK->CLKDIV0 = (CLK->CLKDIV0 & (~CLK_CLKDIV0_HCLKDIV_Msk)) | CLK_CLKDIV0_HCLK(1);

    /* Set PLL to Power-down mode */
    CLK->PLLCTL |= CLK_PLLCTL_PD_Msk;

    /* Enable HXT clock (external XTAL 12MHz) */
    CLK->PWRCTL |= CLK_PWRCTL_HXTEN_Msk;

    /* Wait for HXT clock ready */
    u32TimeOutCnt = __HIRC;
    while(!(CLK->STATUS & CLK_STATUS_HXTSTB_Msk))
		if(--u32TimeOutCnt == 0) break;

    /* Set core clock as PLL_CLOCK from PLL */
    CLK->PLLCTL = PLLCTL_SETTING;
    u32TimeOutCnt = __HIRC;
    while(!(CLK->STATUS & CLK_STATUS_PLLSTB_Msk))
		if(--u32TimeOutCnt == 0) break;
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLKSEL_Msk)) | CLK_CLKSEL0_HCLKSEL_PLL;

    /* Update System Core Clock */
    PllClock        = PLL_CLOCK;            // PLL
    SystemCoreClock = PLL_CLOCK / 1;        // HCLK
    CyclesPerUs     = PLL_CLOCK / 1000000;  // For CLK_SysTickDelay()

    /* Enable UART module clock */
    CLK->APBCLK0 |= CLK_APBCLK0_UART0CKEN_Msk;

    /* Select UART module clock source as HXT and UART module clock divider as 1 */
    CLK->CLKSEL1 = (CLK->CLKSEL1 & (~CLK_CLKSEL1_UARTSEL_Msk)) | CLK_CLKSEL1_UARTSEL_HXT;
    CLK->CLKDIV0 = (CLK->CLKDIV0 & (~CLK_CLKDIV0_UARTDIV_Msk)) | 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;

    /* Set PD multi-function pin for EINT0(PD.2) and EINT1(PD.3) */
    SYS->GPD_MFPL = (SYS->GPD_MFPL & (~SYS_GPD_MFPL_PD2MFP_Msk)) | SYS_GPD_MFPL_PD2MFP_INT0;
    SYS->GPD_MFPL = (SYS->GPD_MFPL & (~SYS_GPD_MFPL_PD3MFP_Msk)) | SYS_GPD_MFPL_PD3MFP_INT1;
}

void UART0_Init()
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 */
    SYS->IPRST1 |=  SYS_IPRST1_UART0RST_Msk;
    SYS->IPRST1 &= ~SYS_IPRST1_UART0RST_Msk;

    /* Configure UART0 and set UART0 baud rate */
    UART0->BAUD = UART_BAUD_MODE2 | UART_BAUD_MODE2_DIVIDER(__HXT, 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 @ %d Hz\n", SystemCoreClock);
    printf("+------------------------------------------------------------+\n");
    printf("|    GPIO EINT0/EINT1 Interrupt and De-bounce Sample Code    |\n");
    printf("+------------------------------------------------------------+\n\n");

    /*-----------------------------------------------------------------------------------------------------*/
    /* GPIO External Interrupt Function Test                                                               */
    /*-----------------------------------------------------------------------------------------------------*/
    printf("EINT0(PD.2) and EINT1(PD.3) are used to test interrupt \n");

    /* Configure PD.2 as EINT0 pin and enable interrupt by falling edge trigger */
    PD->MODE = (PD->MODE & (~GPIO_MODE_MODE2_Msk)) | (GPIO_MODE_INPUT << GPIO_MODE_MODE2_Pos);
    PD->INTTYPE |= (GPIO_INTTYPE_EDGE << GPIO_INTTYPE_TYPE2_Pos);
    PD->INTEN |= GPIO_INTEN_FLIEN2_Msk;
    NVIC_EnableIRQ(EINT024_IRQn);

    /* Configure PD.3 as EINT1 pin and enable interrupt by falling and rising edge trigger */
    PD->MODE = (PD->MODE & (~GPIO_MODE_MODE3_Msk)) | (GPIO_MODE_INPUT << GPIO_MODE_MODE3_Pos);
    PD->INTTYPE |= (GPIO_INTTYPE_EDGE << GPIO_INTTYPE_TYPE3_Pos);
    PD->INTEN |= (GPIO_INTEN_FLIEN3_Msk | GPIO_INTEN_RHIEN3_Msk);
    NVIC_EnableIRQ(EINT135_IRQn);

    /* Enable interrupt de-bounce function and select de-bounce sampling cycle time is 1024 clocks of LIRC clock */
    GPIO->DBCTL = (GPIO_DBCTL_ICLK_ON | GPIO_DBCTL_DBCLKSRC_LIRC | GPIO_DBCTL_DBCLKSEL_1024);
    PD->DBEN |= (BIT2 | BIT3);

    /* Waiting for interrupts */
    while(1);
}

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