text: /**
   * \file
   *
   * \brief Low-level initialization functions called upon chip startup.
   *
   * Copyright (c) 2018 Microchip Technology Inc.
   *
   * \asf_license_start
   *
   * \page License
   *
   * SPDX-License-Identifier: Apache-2.0
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may
   * not use this file except in compliance with the License.
   * You may obtain a copy of the Licence at
   * 
   * http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   * \asf_license_stop
   *
   */
  
  #include "samc20.h"
  
  /**
   * Initial system clock frequency. The System RC Oscillator (RCSYS) provides
   *  the source for the main clock at chip startup.
   */
  #define __SYSTEM_CLOCK    (4000000)
  
  uint32_t SystemCoreClock = __SYSTEM_CLOCK;/*!< System Clock Frequency (Core Clock)*/
  
  /**
   * Initialize the system
   *
   * @brief  Setup the microcontroller system.
   *         Initialize the System and update the SystemCoreClock variable.
   */
  void SystemInit(void)
  {
          // Keep the default device state after reset
          SystemCoreClock = __SYSTEM_CLOCK;
          return;
  }
  
  /**
   * Update SystemCoreClock variable
   *
   * @brief  Updates the SystemCoreClock with current core Clock
   *         retrieved from cpu registers.
   */
  void SystemCoreClockUpdate(void)
  {
          // Not implemented
          SystemCoreClock = __SYSTEM_CLOCK;
          return;
  }
  