lowlevel.c
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/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support - ROUSSET -
* ----------------------------------------------------------------------------
* Copyright (c) 2006, 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 disclaiimer below.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the disclaimer below in the documentation and/or
* other materials provided with the distribution.
*
* 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 Name : lowlevel.c
* Object : low level initialization file
* Creation : FDy 20-Nov-2006
*-----------------------------------------------------------------------------
*/
/* Include Standard files */
#include "project.h"
/*-----------------------------------------------------------------------------
* Function Name : default_spurious_handler
* Object : default handler for spurious interrupt
*-----------------------------------------------------------------------------*/
void default_spurious_handler(void)
{
dbgu_print_ascii("-F- Spurious Interrupt\n\r ");
while (1);
}
/*-----------------------------------------------------------------------------
* Function Name : default_fiq_handler
* Object : default handler for fast interrupt
*-----------------------------------------------------------------------------*/
void default_fiq_handler(void)
{
dbgu_print_ascii("-F- Unexpected FIQ Interrupt\n\r ");
while (1);
}
/*-----------------------------------------------------------------------------
* Function Name : default_irq_handler
* Object : default handler for irq
*-----------------------------------------------------------------------------*/
void default_irq_handler(void)
{
dbgu_print_ascii("-F- Unexpected IRQ Interrupt\n\r ");
while (1);
}
/*-----------------------------------------------------------------------------
* Function Name : lowlevel_init
* Object : This function performs very low level HW initialization
* this function can use a Stack, depending the compilation
* optimization mode
*-----------------------------------------------------------------------------*/
void lowlevel_init(void)
{
unsigned char i = 0;
///////////////////////////////////////////////////////////////////////////
// Init PMC Step 1. Enable Main Oscillator
// Main Oscillator startup time is board specific:
// Main Oscillator Startup Time worst case (3MHz) corresponds to 15ms
// (0x40 for AT91C_CKGR_OSCOUNT field)
///////////////////////////////////////////////////////////////////////////
AT91C_BASE_PMC->PMC_MOR = (((AT91C_CKGR_OSCOUNT & (0x40 << 8)) | AT91C_CKGR_MOSCEN));
// Wait Main Oscillator stabilization
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MOSCS));
///////////////////////////////////////////////////////////////////////////
// Init PMC Step 2.
// Set PLLA to 200MHz (198,656MHz)
// PLL Startup time depends on PLL RC filter: worst case is choosen
///////////////////////////////////////////////////////////////////////////
AT91C_BASE_PMC->PMC_PLLAR = AT91C_CKGR_SRCA |
AT91C_CKGR_OUTA_2 |
(0x3F << 8) |
(AT91C_CKGR_MULA & (0x6D << 16)) |
(AT91C_CKGR_DIVA & 9);
// Wait for PLLA stabilization
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_LOCKA));
// Wait until the master clock is established for the case we already
// turn on the PLLA
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
///////////////////////////////////////////////////////////////////////////
// Init PMC Step 3.
// Selection of Master Clock MCK equal to (Processor Clock PCK) PLLA/2=100MHz
// The PMC_MCKR register must not be programmed in a single write operation
// (see. Product Errata Sheet)
///////////////////////////////////////////////////////////////////////////
AT91C_BASE_PMC->PMC_MCKR = AT91C_PMC_PRES_CLK | AT91C_PMC_MDIV_2;
// Wait until the master clock is established
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
AT91C_BASE_PMC->PMC_MCKR |= AT91C_PMC_CSS_PLLA_CLK;
// Wait until the master clock is established
while (!(AT91C_BASE_PMC->PMC_SR & AT91C_PMC_MCKRDY));
///////////////////////////////////////////////////////////////////////////
// Reset AIC: assign default handler for each interrupt source
///////////////////////////////////////////////////////////////////////////
AT91C_BASE_AIC->AIC_SVR[0] = (int) default_fiq_handler ;
for (i = 1; i < 31; i++) {
AT91C_BASE_AIC->AIC_SVR[i] = (int) default_irq_handler ;
}
AT91C_BASE_AIC->AIC_SPU = (unsigned int) default_spurious_handler;
// Perform 8 IT acknoledge (write any value in EOICR)
for (i = 0; i < 8 ; i++) {
AT91C_BASE_AIC->AIC_EOICR = 0;
}
///////////////////////////////////////////////////////////////////////////
// Disable Watchdog
///////////////////////////////////////////////////////////////////////////
AT91C_BASE_WDTC->WDTC_WDMR = AT91C_WDTC_WDDIS;
///////////////////////////////////////////////////////////////////////////
// Remap
///////////////////////////////////////////////////////////////////////////
AT91C_BASE_MATRIX->MATRIX_MRCR = AT91C_MATRIX_RCA926I | AT91C_MATRIX_RCA926D;
}