1  /**
 2   * \file
 3   *
 4   * \brief Low-level initialization functions called upon chip startup
 5   *
 6   * Copyright (c) 2017 Microchip Technology Inc.
 7   *
 8   * \asf_license_start
 9   *
10   * \page License
11   *
12   * SPDX-License-Identifier: Apache-2.0
13   *
14   * Licensed under the Apache License, Version 2.0 (the "License"); you may
15   * not use this file except in compliance with the License.
16   * You may obtain a copy of the Licence at
17   * 
18   * http://www.apache.org/licenses/LICENSE-2.0
19   * 
20   * Unless required by applicable law or agreed to in writing, software
21   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
22   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
23   * See the License for the specific language governing permissions and
24   * limitations under the License.
25   *
26   * \asf_license_stop
27   *
28   */
29  
30  #ifndef _SYSTEM_SAMD21_H_INCLUDED_
31  #define _SYSTEM_SAMD21_H_INCLUDED_
32  
33  #ifdef __cplusplus
34  extern "C" {
35  #endif
36  
37  #include <stdint.h>
38  
39  extern uint32_t SystemCoreClock;   /*!< System Clock Frequency (Core Clock)  */
40  
41  void SystemInit(void);
42  void SystemCoreClockUpdate(void);
43  
44  #ifdef __cplusplus
45  }
46  #endif
47  
48  #endif /* SYSTEM_SAMD21_H_INCLUDED */