/**************************************************************************//**
 * @file     main.c
 * @version  V3.00
 * $Revision: 4 $
 * $Date: 15/05/22 2:32p $
 * @brief    Implement timer1 event counter function to count the external input event.
 * @note
 * Copyright (C) 2013 Nuvoton Technology Corp. All rights reserved.
 ******************************************************************************/
#include <stdio.h>
#include "M051Series.h"

#define PLLCON_SETTING      CLK_PLLCON_50MHz_HXT
#define PLL_CLOCK           50000000


/*---------------------------------------------------------------------------------------------------------*/
/* Global Interface Variables Declarations                                                                 */
/*---------------------------------------------------------------------------------------------------------*/
volatile uint32_t g_au32TMRINTCount[4] = {0};


/*---------------------------------------------------------------------------------------------------------*/
/*  Create Counter Source by GPIO PORT2                                                                    */
/*---------------------------------------------------------------------------------------------------------*/
void GeneratePORT2Counter(uint32_t u32Pin, uint32_t u32Counts)
{
    while(u32Counts--)
    {
        GPIO_PIN_ADDR(2, u32Pin) = 1;
        GPIO_PIN_ADDR(2, u32Pin) = 0;
    }
}

/**
 * @brief       Timer1 IRQ
 *
 * @param       None
 *
 * @return      None
 *
 * @details     The Timer1 default IRQ, declared in startup_M051Series.s.
 */
void TMR1_IRQHandler(void)
{
    if(TIMER_GetIntFlag(TIMER1) == 1)
    {
        /* Clear Timer1 time-out interrupt flag */
        TIMER_ClearIntFlag(TIMER1);

        g_au32TMRINTCount[1]++;
    }
}

void SYS_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init System Clock                                                                                       */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Enable IRC22M clock */
    CLK->PWRCON |= CLK_PWRCON_IRC22M_EN_Msk;

    /* Waiting for IRC22M clock ready */
    while(!(CLK->CLKSTATUS & CLK_CLKSTATUS_IRC22M_STB_Msk));

    /* Switch HCLK clock source to HIRC */
    CLK->CLKSEL0 = CLK_CLKSEL0_HCLK_S_HIRC;

    /* Set PLL to Power-down mode and PLL_STB bit in CLKSTATUS register will be cleared by hardware.*/
    CLK->PLLCON |= CLK_PLLCON_PD_Msk;

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

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

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

    /* Switch HCLK clock source to PLL, STCLK to HCLK/2 */
    CLK->CLKSEL0 = CLK_CLKSEL0_STCLK_S_HCLK_DIV2 | CLK_CLKSEL0_HCLK_S_PLL;

    /* Enable peripheral clock */
    CLK->APBCLK = CLK_APBCLK_UART0_EN_Msk | CLK_APBCLK_TMR1_EN_Msk;

    /* Peripheral clock source */
    CLK->CLKSEL1 = CLK_CLKSEL1_UART_S_PLL | CLK_CLKSEL1_TMR1_S_HCLK;

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

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set P3 multi-function pins for UART0 RXD, TXD */
    SYS->P3_MFP &= ~(SYS_MFP_P30_Msk | SYS_MFP_P31_Msk);
    SYS->P3_MFP |=  (SYS_MFP_P30_RXD0 | SYS_MFP_P31_TXD0);   
    
    /* Set P3 multi-function pins for T1 */
    SYS->P3_MFP &= ~SYS_MFP_P35_Msk;
    SYS->P3_MFP |= SYS_MFP_P35_T1;
}

void UART0_Init(void)
{
    /*---------------------------------------------------------------------------------------------------------*/
    /* Init UART                                                                                               */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Reset UART */
    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(PllClock, 115200);
    UART0->LCR = UART_WORD_LEN_8 | UART_PARITY_NONE | UART_STOP_BIT_1;
}

/*---------------------------------------------------------------------------------------------------------*/
/*  MAIN function                                                                                          */
/*---------------------------------------------------------------------------------------------------------*/
int main(void)
{
    volatile uint32_t u32InitCount;

    /* 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();
#if !( __GNUC__ )
    printf("\n\nCPU @ %d Hz\n", SystemCoreClock);
#endif
    printf("+-------------------------------------------------+\n");
    printf("|    Timer1 External Counter Input Sample Code    |\n");
    printf("+-------------------------------------------------+\n\n");

    printf("# Timer Settings:\n");
    printf("  Timer1: Clock source is HCLK(50 MHz); Continuous counting mode; Interrupt enable;\n");
    printf("          External counter input enable; TCMP is 56789.\n");
    printf("# Connect P2.0 to T1 pin and pull P2.0 High/Low as T1 counter input source.\n\n");

    /* Configure P2.0 as GPIO output pin and pull pin status to Low first */
    P2->PMD = 0xFFFD;
    P20 = 0;

    /* Enable Timer1 NVIC */
    NVIC_EnableIRQ(TMR1_IRQn);

    /* Clear Timer1 interrupt counts to 0 */
    g_au32TMRINTCount[1] = 0;

    /* Enable Timer1 external counter input function */
    TIMER1->TCMPR = 56789;
    TIMER1->TCSR = TIMER_TCSR_CEN_Msk | TIMER_TCSR_IE_Msk | TIMER_TCSR_CTB_Msk | TIMER_CONTINUOUS_MODE;

    /* To check if TDR of Timer1 must be 0 as default value */
    if(TIMER_GetCounter(TIMER1) != 0)
    {
        printf("Default counter value is not 0. (%d)\n", TIMER_GetCounter(TIMER1));

        /* Stop Timer1 counting */
        TIMER1->TCSR = 0;
        while(1);
    }

    /* To generate one counter event to T1 pin */
    GeneratePORT2Counter(0, 1);

    /* To check if TDR of Timer1 must be 1 */
    while(TIMER_GetCounter(TIMER1) == 0);
    if(TIMER_GetCounter(TIMER1) != 1)
    {
        printf("Get unexpected counter value. (%d)\n", TIMER_GetCounter(TIMER1));

        /* Stop Timer1 counting */
        TIMER1->TCSR = 0;
        while(1);
    }

    /* To generate remains counts to T1 pin */
    GeneratePORT2Counter(0, (56789 - 1));

    while(1)
    {
        if((g_au32TMRINTCount[1] == 1) && (TIMER_GetCounter(TIMER1) == 56789))
        {
            printf("Timer1 external counter input function ... PASS.\n");
            break;
        }
    }

    /* Stop Timer1 counting */
    TIMER1->TCSR = 0;

    while(1);
}

/*** (C) COPYRIGHT 2013 Nuvoton Technology Corp. ***/
