Subversion Repositories openrisc_2011-10-31

/* ----------------------------------------------------------------------------

 *         ATMEL Microcontroller Software Support

 * ----------------------------------------------------------------------------

 * Copyright (c) 2008, 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.

 * ----------------------------------------------------------------------------

 */

//------------------------------------------------------------------------------

//         Headers

//------------------------------------------------------------------------------

#include "board.h"

#include "board_memories.h"

//------------------------------------------------------------------------------

//         Local definitions

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

/// \page "SAM9XE - Oscillator & PLL Parameters"

/// This page lists the parameters which are set for the PLL and main

/// oscillator configuration.

///

/// !Parameters

/// - BOARD_OSCOUNT

/// - BOARD_CKGR_PLLA

/// - BOARD_PLLACOUNT

/// - BOARD_MULA

/// - BOARD_DIVA

/// - BOARD_CKGR_PLLB

/// - BOARD_PLLBCOUNT

/// - BOARD_MULB

/// - BOARD_DIVB

/// - BOARD_USBDIV

/// - BOARD_PRESCALER

/// Main oscillator startup time (in number of slow clock ticks). 

#define BOARD_OSCOUNT           (AT91C_CKGR_OSCOUNT & (64 << 8))

/// PLLA frequency range.

#define BOARD_CKGR_PLLA         (AT91C_CKGR_SRCA | AT91C_CKGR_OUTA_2)

/// PLLA startup time (in number of slow clock ticks).

#define BOARD_PLLACOUNT         (63 << 8)

/// PLLA MUL value.

#define BOARD_MULA              (AT91C_CKGR_MULA & (96 << 16))

/// PLLA DIV value.

#define BOARD_DIVA              (AT91C_CKGR_DIVA & 9)

/// PLLB frequency range

#define BOARD_CKGR_PLLB         AT91C_CKGR_OUTB_1

/// PLLB startup time (in number of slow clock ticks).

#define BOARD_PLLBCOUNT         BOARD_PLLACOUNT

/// PLLB MUL value.

#define BOARD_MULB              (124 << 16)

/// PLLB DIV value.

#define BOARD_DIVB              12

/// USB PLL divisor value to obtain a 48MHz clock.

#define BOARD_USBDIV            AT91C_CKGR_USBDIV_2

/// Master clock prescaler value.

#define BOARD_PRESCALER         AT91C_PMC_MDIV_2

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

//         Local functions

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

/// Default spurious interrupt handler

//------------------------------------------------------------------------------

void DefaultSpuriousHandler(void)

{

    while (1);

}

//------------------------------------------------------------------------------

/// Default handler for fast interrupt requests.

//------------------------------------------------------------------------------

void DefaultFiqHandler(void)

{

    while (1);

}

//------------------------------------------------------------------------------

/// Default handler for standard interrupt requests.

//------------------------------------------------------------------------------

void DefaultIrqHandler(void)

{

    while (1);

}

//------------------------------------------------------------------------------

//         Global functions

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

/// Performs the low-level initialization of the chip.

//------------------------------------------------------------------------------

void LowLevelInit(void)

{

    unsigned char i;

    // Set flash wait states

    //----------------------

    AT91C_BASE_EFC->EFC_FMR = 6 << 8;

//#if !defined(sdram)

    // Initialize main oscillator

    //---------------------------

    AT91C_BASE_PMC->PMC_MOR = BOARD_OSCOUNT | AT91C_CKGR_MOSCEN;

    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS));

    // Initialize PLLA at 200MHz (198.656)

    AT91C_BASE_PMC->PMC_PLLAR = BOARD_CKGR_PLLA

                                | BOARD_PLLACOUNT

                                | BOARD_MULA

                                | BOARD_DIVA;

    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKA));

    // Initialize PLLB for USB usage

    AT91C_BASE_PMC->PMC_PLLBR = BOARD_USBDIV

                                | BOARD_CKGR_PLLB

                                | BOARD_PLLBCOUNT

                                | BOARD_MULB

                                | BOARD_DIVB;

    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKB));

    // Wait for the master clock if it was already initialized

    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));

    // Switch to fast clock

    //---------------------

    // Switch to main oscillator + prescaler

    AT91C_BASE_PMC->PMC_MCKR = BOARD_PRESCALER;

    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));

    // Switch to PLL + prescaler

    AT91C_BASE_PMC->PMC_MCKR |= AT91C_PMC_CSS_PLLA_CLK;

    while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));

//#endif //#if !defined(sdram)

    // Initialize AIC

    //---------------

    AT91C_BASE_AIC->AIC_IDCR = 0xFFFFFFFF;

    AT91C_BASE_AIC->AIC_SVR[0] = (unsigned int) DefaultFiqHandler;

    for (i = 1; i < 31; i++) {

        AT91C_BASE_AIC->AIC_SVR[i] = (unsigned int) DefaultIrqHandler;

    }

    AT91C_BASE_AIC->AIC_SPU = (unsigned int) DefaultSpuriousHandler;

    // Unstack nested interrupts

    for (i = 0; i < 8 ; i++) {

        AT91C_BASE_AIC->AIC_EOICR = 0;

    }

    // Watchdog initialization

    //------------------------

    AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;

    // Remap

    //------

    BOARD_RemapRam();

    // Disable RTT and PIT interrupts (potential problem when program A

    // configures RTT, then program B wants to use PIT only, interrupts

    // from the RTT will still occur since they both use AT91C_ID_SYS)

    AT91C_BASE_RTTC->RTTC_RTMR &= ~(AT91C_RTTC_ALMIEN | AT91C_RTTC_RTTINCIEN);

    AT91C_BASE_PITC->PITC_PIMR &= ~AT91C_PITC_PITIEN;

}