main.c

/*******************************************************************************
 * File Name:   main.c
 *
 * Description: This is the source code for the XMC MCU: SCU-Hibernate
 *              for ModusToolbox.
 *
 * Related Document: See README.md
 *
 *******************************************************************************
 *
 * $ Copyright (c) 2015-YEAR, Infineon Technologies AG $
 * All rights reserved.
 *
 * Boost Software License - Version 1.0 - August 17th, 2003
 *
 * Permission is hereby granted, free of charge, to any person or organization
 * obtaining a copy of the software and accompanying documentation covered by
 * this license (the "Software") to use, reproduce, display, distribute,
 * execute, and transmit the Software, and to prepare derivative works of the
 * Software, and to permit third-parties to whom the Software is furnished to
 * do so, all subject to the following:
 *
 * The copyright notices in the Software and this entire statement, including
 * the above license grant, this restriction and the following disclaimer,
 * must be included in all copies of the Software, in whole or in part, and
 * all derivative works of the Software, unless such copies or derivative
 * works are solely in the form of machine-executable object code generated by
 * a source language processor.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 *******************************************************************************/

#include "cybsp.h"
#include "cy_utils.h"
#include "cy_retarget_io.h"
#include <stdio.h>

/*******************************************************************************
 * Defines
 *******************************************************************************/

/* Define macro to enable/disable printing of debug messages */
#define ENABLE_XMC_DEBUG_PRINT              (0)

/* Time delay */
#define TIME_DELAY                          (5)

/*******************************************************************************
 * Function Name: delay
 *******************************************************************************
 * Summary:
 * This is the delay generation function based on the MCU clock cycles
 *
 * Parameters:
 *  uint32_t cycles
 *
 * Return:
 *  void
 *
 ******************************************************************************/
void delay(uint32_t cycles)
{
    while(--cycles)
    {
        __NOP();       /* No operation */
    }
}

/*******************************************************************************
 * Function Name: main
 *******************************************************************************
 * Summary:
 * The device starts showing the LED1 on, and will enter internal hibernate
 * after ~5s, indicated by the RESET led. After ~30s a wakeup event from the
 * RTC will trigger and restart the device. Additionaly the HIB_IO_0 button
 * can be used to wake up the device before expiring the 30s.
 *
 * Parameters:
 *  none
 *
 * Return:
 *  int
 *
 *******************************************************************************/
int main(void)
{
    cy_rslt_t result;

    /* Initialize the device and board peripherals */
    result = cybsp_init();
    if (result != CY_RSLT_SUCCESS)
    {
        CY_ASSERT(0);
    }

    /* Initialize printf retarget */
    cy_retarget_io_init(CYBSP_DEBUG_UART_HW);

    #if ENABLE_XMC_DEBUG_PRINT
    printf("Initialization done\r\n");
    #endif

    if (XMC_SCU_HIB_IsHibernateDomainEnabled() == true)
    {
      /* Read the status bits to see what caused the wake. Clear the wake
       * source so that the device can be put into hibernate mode again. */
      int32_t event = XMC_SCU_HIB_GetEventStatus();
      XMC_SCU_HIB_ClearEventStatus(event);

      if(event & XMC_SCU_HIB_EVENT_WAKEUP_ON_RTC)
      {
        /* Clears periodic and alarm event(s) status*/
        XMC_RTC_ClearEvent(XMC_RTC_EVENT_ALARM);
        printf("Wake from hibernate due to RTC alarm\r\n");
      }
      else
      {
        printf("Wake from hibernate due to HIB_IO_0_PIN\r\n");
      }

      /* Clear detection status of wakeup from hibernate mode */
      XMC_SCU_HIB_ClearWakeupEventDetectionStatus();

      /* Clears the reset reason bits in the reset status register.
       * recommended to ensure a clear indication of the cause of next reset. */
      XMC_SCU_RESET_ClearDeviceResetReason();
      printf("Hibernation enabled\r\n");
    }
    else
    {
      /* Powers up the hibernation domain and moves it out of reset state. */
      XMC_SCU_HIB_EnableHibernateDomain();

      /* Selects the source of Standby clock */
      XMC_SCU_HIB_SetStandbyClockSource(XMC_SCU_HIB_STDBYCLKSRC_OSI);

      /* Selects the source of RTC clock */
      XMC_SCU_HIB_SetRtcClockSource(XMC_SCU_HIB_RTCCLKSRC_OSI);
    }

    /* Stop the Already running RTC for new configuration */
    XMC_RTC_Stop();

    XMC_GPIO_SetOutputHigh(CYBSP_USER_LED_PORT, CYBSP_USER_LED_PIN);

    /* Delay generated for 5s */
    delay((XMC_SCU_CLOCK_GetCpuClockFrequency()/2) * TIME_DELAY);

    /* Selects input for Wake-Up from Hibernate */
    XMC_SCU_HIB_SetWakeupTriggerInput(XMC_SCU_HIB_IO_0);

    /* Enable hibernate wakeup event source
     * In XMC4200 and XMC4400 Kits, HIB_IO_0 pin is externally pulled up */
    XMC_SCU_HIB_EnableEvent(XMC_SCU_HIB_EVENT_WAKEUP_ON_NEG_EDGE | XMC_SCU_HIB_EVENT_WAKEUP_ON_RTC);

    /* RTC initialization */
    XMC_RTC_Init(&RTC_0_config);

    /* Enable Wakeup from hibernate mode on RTC alarm event*/
    XMC_RTC_EnableHibernationWakeUp(XMC_RTC_WAKEUP_EVENT_ON_ALARM);

    /* Start RTC */
    XMC_RTC_Start();

    /* Request enter external hibernate state */
    XMC_SCU_HIB_EnterHibernateStateEx(XMC_SCU_HIB_HIBERNATE_MODE_INTERNAL);

    /* Infinite loop */
    for (;;)
    {
    }
}

/* [] END OF FILE */