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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"
#include <pmc/pmc.h>
//------------------------------------------------------------------------------
// Internal definitions
//------------------------------------------------------------------------------
// Startup time of main oscillator (in number of slow clock ticks).
#define BOARD_OSCOUNT (AT91C_CKGR_OSCOUNT & (0x40 << 8))
// USB PLL divisor value to obtain a 48MHz clock.
#define BOARD_USBDIV AT91C_CKGR_USBDIV_1
// PLL frequency range.
#define BOARD_CKGR_PLL AT91C_CKGR_OUT_0
// PLL startup time (in number of slow clock ticks).
#define BOARD_PLLCOUNT (16 << 8)
// PLL MUL value.
#define BOARD_MUL (AT91C_CKGR_MUL & (72 << 16))
// PLL DIV value.
#define BOARD_DIV (AT91C_CKGR_DIV & 14)
// Master clock prescaler value.
#define BOARD_PRESCALER AT91C_PMC_PRES_CLK_2
//------------------------------------------------------------------------------
// Internal 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 )
{
unsigned char i;
/* Set flash wait states in the EFC
**********************************/
/* 48MHz = 1 wait state */
#if defined(at91sam7x512)
AT91C_BASE_EFC0->EFC_FMR = AT91C_MC_FWS_1FWS;
AT91C_BASE_EFC1->EFC_FMR = AT91C_MC_FWS_1FWS;
#elif defined(at91sam7x128) || defined(at91sam7x256)
AT91C_BASE_MC->MC_FMR = AT91C_MC_FWS_1FWS;
#else
#error No chip definition ?
#endif
/* Initialize main oscillator
****************************/
AT91C_BASE_PMC->PMC_MOR = BOARD_OSCOUNT | AT91C_CKGR_MOSCEN;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS));
/* Initialize PLL at 96MHz (96.109) and USB clock to 48MHz */
AT91C_BASE_PMC->PMC_PLLR = BOARD_USBDIV | BOARD_CKGR_PLL | BOARD_PLLCOUNT
| BOARD_MUL | BOARD_DIV;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCK));
/* 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 slow clock + prescaler */
AT91C_BASE_PMC->PMC_MCKR = BOARD_PRESCALER;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
/* Switch to fast clock + prescaler */
AT91C_BASE_PMC->PMC_MCKR |= AT91C_PMC_CSS_PLL_CLK;
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
/* 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
*******/
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;
}
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