/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 9 $
 * $Date: 15/07/10 11:35a $
 * @brief    Show how to set GPIO pin mode and use pin data input/output control.
 * @note
 * @copyright SPDX-License-Identifier: Apache-2.0
 * @copyright Copyright (C) 2014 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "NUC131.h"


#define PLLCON_SETTING  CLK_PLLCON_50MHz_HXT
#define PLL_CLOCK       50000000


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

    /* Enable Internal RC 22.1184MHz clock */
    CLK->PWRCON |= CLK_PWRCON_OSC22M_EN_Msk;

    /* Waiting for Internal RC clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_OSC22M_STB_Msk));

    /* Switch HCLK clock source to Internal RC and HCLK source divide 1 */
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLK_S_Msk)) | CLK_CLKSEL0_HCLK_S_HIRC;
    CLK->CLKDIV = (CLK->CLKDIV & (~CLK_CLKDIV_HCLK_N_Msk)) | CLK_CLKDIV_HCLK(1);

    /* Set PLL to Power-down mode */
    CLK->PLLCON |= CLK_PLLCON_PD_Msk;

    /* Enable external XTAL 12MHz clock */
    CLK->PWRCON |= CLK_PWRCON_XTL12M_EN_Msk;

    /* Waiting for external XTAL clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_XTL12M_STB_Msk));

    /* Set core clock as PLL_CLOCK from PLL */
    CLK->PLLCON = PLLCON_SETTING;
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_PLL_STB_Msk));
    CLK->CLKSEL0 = (CLK->CLKSEL0 & (~CLK_CLKSEL0_HCLK_S_Msk)) | CLK_CLKSEL0_HCLK_S_PLL;

    /* Update System Core Clock */
    /* User can use SystemCoreClockUpdate() to calculate PllClock, SystemCoreClock and CyclesPerUs automatically. */
    //SystemCoreClockUpdate();
    PllClock        = PLL_CLOCK;            // PLL
    SystemCoreClock = PLL_CLOCK / 1;        // HCLK
    CyclesPerUs     = PLL_CLOCK / 1000000;  // For CLK_SysTickDelay()

    /* Enable UART module clock */
    CLK->APBCLK |= CLK_APBCLK_UART0_EN_Msk;

    /* Select UART module clock source */
    CLK->CLKSEL1 = (CLK->CLKSEL1 & (~CLK_CLKSEL1_UART_S_Msk)) | CLK_CLKSEL1_UART_S_HXT;

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

    /* Set GPB multi-function pins for UART0 RXD(PB.0) and TXD(PB.1) */
    SYS->GPB_MFP &= ~(SYS_GPB_MFP_PB0_Msk | SYS_GPB_MFP_PB1_Msk);
    SYS->GPB_MFP |= (SYS_GPB_MFP_PB0_UART0_RXD | SYS_GPB_MFP_PB1_UART0_TXD);

}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART0 */
    SYS->IPRSTC2 |=  SYS_IPRSTC2_UART0_RST_Msk;
    SYS->IPRSTC2 &= ~SYS_IPRSTC2_UART0_RST_Msk;

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

/*---------------------------------------------------------------------------------------------------------*/
/* MAIN function                                                                                           */
/*---------------------------------------------------------------------------------------------------------*/
int32_t main(void)
{
    int32_t i32Err;

    /* 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("|    PB.2(Output) and PC.1(Input) Sample Code     |\n");
    printf("+-------------------------------------------------+\n\n");

    /* Configure PB.2 as Output mode and PC.1 as Input mode */
    PB->PMD = (PB->PMD & (~GPIO_PMD_PMD2_Msk)) | (GPIO_PMD_OUTPUT << GPIO_PMD_PMD2_Pos);
    PC->PMD = (PC->PMD & (~GPIO_PMD_PMD1_Msk)) | (GPIO_PMD_INPUT << GPIO_PMD_PMD1_Pos);

    i32Err = 0;
    printf("GPIO PB.2(output mode) connect to PC.1(input mode) ......");

    /* Use Pin Data Input/Output Control to pull specified I/O or get I/O pin status */
    /* Pull PB.2 to Low and check PC.1 status */
    PB2 = 0;
    if(PC1 != 0)
    {
        i32Err = 1;
    }

    /* Pull PB.2 to High and check PC.1 status */
    PB2 = 1;
    if(PC1 != 1)
    {
        i32Err = 1;
    }

    if(i32Err)
    {
        printf("  [FAIL].\n");
    }
    else
    {
        printf("  [OK].\n");
    }

    /* Configure PB.2 and PC.1 to default Quasi-bidirectional mode */
    PB->PMD = (PB->PMD & (~GPIO_PMD_PMD2_Msk)) | (GPIO_PMD_QUASI << GPIO_PMD_PMD2_Pos);
    PC->PMD = (PC->PMD & (~GPIO_PMD_PMD1_Msk)) | (GPIO_PMD_QUASI << GPIO_PMD_PMD1_Pos);

    while(1);
}

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