/** * \file * * \brief Low-level initialization functions called upon chip startup. * * Copyright (c) 2015 Atmel Corporation. All rights reserved. * * \asf_license_start * * \page License * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * \asf_license_stop * */ #include "samd21.h" /** * Initial system clock frequency. The System RC Oscillator (RCSYS) provides * the source for the main clock at chip startup. */ #define __SYSTEM_CLOCK (1000000) 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; }