/**************************************************************************//**
 * @file     main.c
 * @version  V1.00
 * $Revision: 3 $
 * $Date: 14/06/11 10:13a $
 * @brief    Use polling mode to check WDT time-out state and reset WDT after
 *           time out occurs
 *
 * @note
 * Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
 *****************************************************************************/
#include <stdio.h>
#include "NUC029FAE.h"


void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/

    /* Unlock protected registers */
    while(SYS->RegLockAddr != 1)
    {
        SYS->RegLockAddr = 0x59;
        SYS->RegLockAddr = 0x16;
        SYS->RegLockAddr = 0x88;
    }

    /* Enable internal RC 22.1184MHz, and  RC 10K (fro WDT) */
    CLK->PWRCON = CLK_PWRCON_IRC22M_EN_Msk | CLK_PWRCON_IRC10K_EN_Msk;

    /* Waiting for clock ready */
    while((CLK->CLKSTATUS & (CLK_CLKSTATUS_IRC22M_STB_Msk | CLK_CLKSTATUS_IRC10K_STB_Msk)) !=
            (CLK_CLKSTATUS_IRC22M_STB_Msk | CLK_CLKSTATUS_IRC10K_STB_Msk));


    /* Enable UART and WDT clock */
    CLK->APBCLK = CLK_APBCLK_UART_EN_Msk | CLK_APBCLK_WDT_EN_Msk;

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


    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set P1 multi-function pins for UART RXD, TXD */
    SYS->P1_MFP = SYS_MFP_P12_RXD | SYS_MFP_P13_TXD;

    /* Lock protected registers */
    SYS->RegLockAddr = 0;
}

void UART_Init(void)
{
    // Set UART to 8 bit character length, 1 stop bit, and no parity
    UART->LCR = UART_LCR_WLS_Msk;
    // 22.1184 MHz reference clock input, for 115200 bps
    // 22118400 / 115200 = 192. Using mode 2 to calculate baudrate, 192 - 2 = 190 = 0xBE
    UART->BAUD = UART_BAUD_DIV_X_EN_Msk | UART_BAUD_DIV_X_ONE_Msk | (0xBE);
}

int32_t main (void)
{
    /* Init System, IP clock and multi-function I/O
       In the end of SYS_Init() will issue SYS_LockReg()
       to lock protected register. If user want to write
       protected register, please issue SYS_UnlockReg()
       to unlock protected register if necessary */
    SYS_Init();

    /* Init UART to 115200-8n1 for print message */
    UART_Init();

    printf("\nThis sample code demonstrate using WDT in polling mode\n");

    // WDT register is locked, so it is necessary to unlock protect register before configure WDT
    while(SYS->RegLockAddr != 1)
    {
        SYS->RegLockAddr = 0x59;
        SYS->RegLockAddr = 0x16;
        SYS->RegLockAddr = 0x88;
    }

    // WDT timeout every 2^14 WDT clock, enable system reset
    WDT->WTCR = WDT_TIMEOUT_2POW14 | WDT_WTCR_WTE_Msk | WDT_WTCR_WTRE_Msk | WDT_WTCR_WTIE_Msk;

    while(1)
    {
        // WDT timeout flag set
        if(WDT->WTCR & WDT_WTCR_WTIF_Msk)
        {
            // Reset WDT and clear time out flag
            WDT->WTCR |= WDT_WTCR_WTR_Msk;
            printf("Reset WDT counter\n");
        }
    }

}

/*** (C) COPYRIGHT 2014 Nuvoton Technology Corp. ***/


