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/* ----------------------------------------------------------------------------
* 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.
* ----------------------------------------------------------------------------
*/
//------------------------------------------------------------------------------
/// \unit
///
/// !Purpose
///
/// Provides the low-level initialization function that gets called on chip
/// startup.
///
/// !Usage
///
/// LowLevelInit() is called in #board_cstartup.S#.
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include "board.h"
#include "board_memories.h"
//------------------------------------------------------------------------------
// Local definitions
//------------------------------------------------------------------------------
/// PLL frequency range.
#define BOARD_CKGR_PLL AT91C_CKGR_OUT_2
/// PLL startup time (in number of slow clock ticks).
#define BOARD_PLLCOUNT AT91C_CKGR_PLLCOUNT
/// PLL MUL value.
#define BOARD_MUL (914 << 16)
/// PLL DIV value.
#define BOARD_DIV 1
/// Master clock prescaler value.
#define BOARD_PRESCALER 0
//------------------------------------------------------------------------------
// Global variables
//------------------------------------------------------------------------------
// SUPC status value read during LowLevelInit(), discarded by read.
unsigned int gLowLevelInitSupcStatus;
//------------------------------------------------------------------------------
// Local functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Default spurious interrupt handler. Infinite loop.
//------------------------------------------------------------------------------
void defaultSpuriousHandler(void)
{
while (1);
}
//------------------------------------------------------------------------------
/// Default handler for fast interrupt requests. Infinite loop.
//------------------------------------------------------------------------------
void defaultFiqHandler(void)
{
while (1);
}
//------------------------------------------------------------------------------
/// Default handler for standard interrupt requests. Infinite loop.
//------------------------------------------------------------------------------
void defaultIrqHandler(void)
{
while (1);
}
//------------------------------------------------------------------------------
// Exported functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Performs the low-level initialization of the chip. This includes EFC, master
/// clock, AIC & watchdog configuration, as well as memory remapping.
//------------------------------------------------------------------------------
void LowLevelInit(void)
{
volatile unsigned int i;
// Set flash wait states in the EFC
// 48MHz = 1 wait state
#if defined(at91sam7l64) || defined(at91sam7l128)
AT91C_BASE_MC->MC_FMR = AT91C_MC_FWS_3FWS;
#else
#error No chip definition ?
#endif
// Enable external oscillator (on first boot only, after that command does nothing)
gLowLevelInitSupcStatus = AT91C_BASE_SUPC->SUPC_SR;
if ((gLowLevelInitSupcStatus & AT91C_SUPC_OSCSEL) != AT91C_SUPC_OSCSEL) {
AT91C_BASE_SUPC->SUPC_CR = (0xA5 << 24) | AT91C_SUPC_XTALSEL;
while ((AT91C_BASE_SUPC->SUPC_SR & AT91C_SUPC_OSCSEL) != AT91C_SUPC_OSCSEL);
}
// Switch to slow clock if necessary (so PLL frequency can be changed)
if ((AT91C_BASE_PMC->PMC_MCKR & AT91C_PMC_CSS) == AT91C_PMC_CSS_PLL_CLK) {
AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_CSS_SLOW_CLK;
while ((AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY) != AT91C_PMC_MCKRDY);
}
// Initialize PLL at 30MHz
AT91C_BASE_PMC->PMC_PLLR = BOARD_CKGR_PLL | BOARD_PLLCOUNT | BOARD_MUL | BOARD_DIV;
while ((AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCK) == 0);
// Switch to PLL
AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_CSS_PLL_CLK;
while ((AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY) == 0);
// 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;
}
// Enable Debug mode
AT91C_BASE_AIC->AIC_DCR = AT91C_AIC_DCR_PROT;
// Watchdog initialization
AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
// Remap the internal SRAM at 0x0
BOARD_RemapRam();
}
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