cpu.c
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/*
* Copyright (C) 2014 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup cpu_nrf51822
* @{
*
* @file
* @brief Implementation of the CPU initialization
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @}
*/
#include "cpu.h"
#include "periph_conf.h"
/**
* @brief Initialize the CPU, set IRQ priorities
*/
void cpu_init(void)
{
/* initialize the Cortex-M core */
cortexm_init();
/* set the correct clock source for HFCLK */
#if CLOCK_CRYSTAL == 32
NRF_CLOCK->XTALFREQ = CLOCK_XTALFREQ_XTALFREQ_32MHz;
NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
NRF_CLOCK->TASKS_HFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0) {}
#elif CLOCK_CRYSTAL == 16
NRF_CLOCK->XTALFREQ = CLOCK_XTALFREQ_XTALFREQ_16MHz;
NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
NRF_CLOCK->TASKS_HFCLKSTART = 1;
while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0) {}
#endif
}