/**************************************************************************//**
 * @file     main.c
 * @version  V1.00
 * @brief    Use the timer periodic mode to generate timer interrupt every 1 second.
 *
 * SPDX-License-Identifier: Apache-2.0
 * @copyright (C) 2020 Nuvoton Technology Corp. All rights reserved.
 ****************************************************************************/
#include <stdio.h>
#include "NuMicro.h"


void TMR0_IRQHandler(void)
{
    static uint32_t sec = 1;
    printf("%d sec\n", sec++);

    /* clear timer interrupt flag */
    TIMER_ClearIntFlag(TIMER0);
}

void SYS_Init(void)
{
    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Enable HIRC */
    CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);

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

    /* Switch HCLK clock source to HIRC */
    CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));

    /* Set both PCLK0 and PCLK1 as HCLK/2 */
    CLK->PCLKDIV = (CLK_PCLKDIV_APB0DIV_DIV2 | CLK_PCLKDIV_APB1DIV_DIV2);

    /* Switch UART0 clock source to HIRC */
    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART0SEL_HIRC, CLK_CLKDIV0_UART0(1));

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

    /* Enable IP clock */
    CLK_EnableModuleClock(TMR0_MODULE);

    /* Select IP clock source */
    CLK_SetModuleClock(TMR0_MODULE, CLK_CLKSEL1_TMR0SEL_HIRC, 0);

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

    /*----------------------------------------------------------------------*/
    /* Init I/O Multi-function                                              */
    /*----------------------------------------------------------------------*/
    /* Set PB multi-function pins for UART0 RXD=PB.6 and TXD=PB.4 */
    SYS->GPB_MFP1 = (SYS->GPB_MFP1 & ~(SYS_GPB_MFP1_PB4MFP_Msk | SYS_GPB_MFP1_PB6MFP_Msk)) |
                    (SYS_GPB_MFP1_PB4MFP_UART0_TXD | SYS_GPB_MFP1_PB6MFP_UART0_RXD);

    /* Lock protected registers */
    SYS_LockReg();
}

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

    /* Configure UART0 and set UART0 baud rate */
    UART_Open(UART0, 115200);
}

int main(void)
{
    int volatile i;

    /* Init System, IP clock and multi-function I/O. */
    SYS_Init();

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

    printf("\nThis sample code use timer to generate interrupt every 1 second \n");

    /* Set timer frequency to 1HZ */
    TIMER_Open(TIMER0, TIMER_PERIODIC_MODE, 1);

    /* Enable timer interrupt */
    TIMER_EnableInt(TIMER0);
    NVIC_EnableIRQ(TMR0_IRQn);

    /* Start Timer 0 */
    TIMER_Start(TIMER0);

    while(1);
}
