/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support
 * ----------------------------------------------------------------------------
 * Copyright (c) 2011, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: 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
 * 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.
 * ----------------------------------------------------------------------------
 */

/**
 * \file
 *
 * Provides the low-level initialization function that called on chip startup.
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "board.h"

/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Performs the low-level initialization of the chip.
 * This includes EFC and master clock configuration.
 * It also enable a low level on the pin NRST triggers a user reset.
 */
extern WEAK void LowLevelInit( void )
{
    /* Set 3 FWS for Embedded Flash Access */
    EFC->EEFC_FMR = EEFC_FMR_FWS(3);
    if ((PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) )  /* Main Oscillator Selection */
    {
        /* Switch MCK to Slow clock  */
        PMC_SetMckSelection(PMC_MCKR_CSS_SLOW_CLK, PMC_MCKR_PRES_CLK);
        /* First, select external clock */
        PMC_SelectExtOsc();
        /* Then, enable Main XTAL oscillator */
        PMC_EnableExtOsc();
        /* Then, cofigure PLLB and switch clock */
        PMC_ConfigureMckWithPllb(0x8, 1, PMC_MCKR_PRES_CLK_2); /* MCK = 12MHz * 8 / 2  = 48MHz */
    }
}
