
/******************************************************************************
 * @file     main.c
 * @version  V0.10
 * $Revision: 2 $
 * $Date: 16/10/25 4:28p $
 * @brief    Demonstrate how ACMP works with internal band-gap voltage.
 * @note
 * Copyright (C) 2016 Nuvoton Technology Corp. All rights reserved.
*****************************************************************************/
#include <stdio.h>
#include "NUC1261.h"


/* Function prototype declaration */
void SYS_Init(void);

int32_t main(void)
{
    /* Unlock protected registers */
    SYS_UnlockReg();
    /* Init System, IP clock and multi-function I/O. */
    SYS_Init();
    /* Lock protected registers */
    SYS_LockReg();

    /* Configure UART0: 115200, 8-bit word, no parity bit, 1 stop bit. */
    UART_Open(UART0, 115200);

    printf("\n\n");
    printf("+---------------------------------------+\n");
    printf("|           ACMP Sample Code            |\n");
    printf("+---------------------------------------+\n");

    printf("\nThis sample code demonstrates ACMP0 function. Using ACMP0_P0 (PB7) as ACMP0\n");
    printf("positive input and using internal band-gap voltage as the negative input.\n");
    printf("The compare result reflects on ACMP0_O (PD6).\n");

    printf("When the voltage of the positive input is greater than the voltage of the negative input,\n");
    printf("the analog comparator outputs logical one; otherwise, it outputs logical zero.\n");
    printf("This sample code will show the expression of the comparator's inputs and a sequence ");
    printf("number when detecting a transition of analog comparator's output.\n");
    printf("Press any key to start ...");
    getchar();
    printf("\n");

    /* Configure ACMP0. Enable ACMP0 and select band-gap voltage as the source of ACMP negative input. */
    ACMP_Open(ACMP01, 0, ACMP_CTL_NEGSEL_VBG, ACMP_CTL_HYSTERESIS_DISABLE);
    /* Enable interrupt */
    ACMP_ENABLE_INT(ACMP01, 0);

    /* Enable ACMP01 interrupt */
    NVIC_EnableIRQ(ACMP01_IRQn);

    while(1);

}

void ACMP01_IRQHandler(void)
{
    static uint32_t u32Cnt = 0;

    /* Clear ACMP 0 interrupt flag */
    ACMP_CLR_INT_FLAG(ACMP01, 0);
    /* Check Comparator 0 Output Status */
    if(ACMP_GET_OUTPUT(ACMP01, 0))
        printf("ACMP0_P voltage > Band-gap voltage (%d)\n", u32Cnt);
    else
        printf("ACMP0_P voltage <= Band-gap voltage (%d)\n", u32Cnt);

    u32Cnt++;
}


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

    /* Enable external 12MHz XTAL */
    CLK_EnableXtalRC(CLK_PWRCTL_HXTEN_Msk);

    /* Waiting for clock ready */
    CLK_WaitClockReady(CLK_STATUS_HXTSTB_Msk);

    /* Select HXT as the clock source of UART */
    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UARTSEL_HXT, CLK_CLKDIV0_UART(1));

    /* Enable UART peripheral clock */
    CLK_EnableModuleClock(UART0_MODULE);
    /* Enable ACMP01 peripheral clock */
    CLK_EnableModuleClock(ACMP01_MODULE);

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

    /*---------------------------------------------------------------------------------------------------------*/
    /* Init I/O Multi-function                                                                                 */
    /*---------------------------------------------------------------------------------------------------------*/
    /* Set PB7 multi-function pin for ACMP0 positive input pin */
    SYS->GPB_MFPL &= ~(SYS_GPB_MFPL_PB7MFP_Msk);
    SYS->GPB_MFPL |= SYS_GPB_MFPL_PB7MFP_ACMP0_P0;

    /* Set PD7 multi-function pin for ACMP0 output pin */
    SYS->GPD_MFPL &= ~(SYS_GPD_MFPL_PD7MFP_Msk);
    SYS->GPD_MFPL |= SYS_GPD_MFPL_PD7MFP_ACMP0_O;

    /* Set PA multi-function pins for UART0 RXD and TXD */
    SYS->GPA_MFPL &= ~(SYS_GPA_MFPL_PA3MFP_Msk | SYS_GPA_MFPL_PA2MFP_Msk);
    SYS->GPA_MFPL |= (SYS_GPA_MFPL_PA3MFP_UART0_RXD | SYS_GPA_MFPL_PA2MFP_UART0_TXD);

    /* Disable digital input path of analog pin ACMP0_P0 to prevent leakage */
    GPIO_DISABLE_DIGITAL_PATH(PB, (1ul << 7));

}


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


