1 /**
2 * \file
3 *
4 * \brief Low-level initialization functions called upon chip startup.
5 *
6 * Copyright (c) 2014-2015 Atmel Corporation. All rights reserved.
7 *
8 * \asf_license_start
9 *
10 * \page License
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright notice,
16 * this list of conditions and the following disclaimer.
17 *
18 * 2. Redistributions in binary form must reproduce the above copyright notice,
19 * this list of conditions and the following disclaimer in the documentation
20 * and/or other materials provided with the distribution.
21 *
22 * 3. The name of Atmel may not be used to endorse or promote products derived
23 * from this software without specific prior written permission.
24 *
25 * 4. This software may only be redistributed and used in connection with an
26 * Atmel microcontroller product.
27 *
28 * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
29 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
30 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
31 * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
32 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
36 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 *
40 * \asf_license_stop
41 *
42 */
43 /*
44 * Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
45 */
46
47 #include "samd21.h"
48
49 /**
50 * Initial system clock frequency. The System RC Oscillator (RCSYS) provides
51 * the source for the main clock at chip startup.
52 */
53 #define __SYSTEM_CLOCK (1000000)
54
55 uint32_t SystemCoreClock = __SYSTEM_CLOCK;/*!< System Clock Frequency (Core Clock)*/
56
57 /**
58 * Initialize the system
59 *
60 * @brief Setup the microcontroller system.
61 * Initialize the System and update the SystemCoreClock variable.
62 */
SystemInit(void)63 void SystemInit(void)
64 {
65 // Keep the default device state after reset
66 SystemCoreClock = __SYSTEM_CLOCK;
67 return;
68 }
69
70 /**
71 * Update SystemCoreClock variable
72 *
73 * @brief Updates the SystemCoreClock with current core Clock
74 * retrieved from cpu registers.
75 */
SystemCoreClockUpdate(void)76 void SystemCoreClockUpdate(void)
77 {
78 // Not implemented
79 SystemCoreClock = __SYSTEM_CLOCK;
80 return;
81 }
82