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system_sam3x.c
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/**
* \file
*
* \brief Provides the low-level initialization functions that called
* on chip startup.
*
* Copyright (c) 2011 - 2013 Atmel Corporation. All rights reserved.
*
* \asf_license_start
*
* \page License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name of Atmel may not be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 4. This software may only be redistributed and used in connection with an
* Atmel microcontroller product.
*
* 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
* EXPRESSLY AND SPECIFICALLY 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.
*
* \asf_license_stop
*
*/
#include "at91sam3x8.h"
#include "system_sam3x.h"
#include <stdint.h>
/* @cond 0 */
/**INDENT-OFF**/
#ifdef __cplusplus
extern "C" {
#endif
/**INDENT-ON**/
/* @endcond */
/* Clock settings (84MHz) */
#define SYS_BOARD_OSCOUNT (CKGR_MOR_MOSCXTST(0x8))
#define SYS_BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \
| CKGR_PLLAR_MULA(0xdUL) \
| CKGR_PLLAR_PLLACOUNT(0x3fUL) \
| CKGR_PLLAR_DIVA(0x1UL))
#define SYS_BOARD_MCKR (PMC_MCKR_PRES_CLK_2 | PMC_MCKR_CSS_PLLA_CLK)
/* Clock Definitions */
#define SYS_UTMIPLL (480000000UL) /* UTMI PLL frequency */
#define SYS_CKGR_MOR_KEY_VALUE CKGR_MOR_KEY(0x37) /* Key to unlock MOR register */
/* FIXME: should be generated by sock */
uint32_t SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
/**
* \brief Setup the microcontroller system.
* Initialize the System and update the SystemFrequency variable.
*/
void SystemInit(void)
{
/* Set FWS according to SYS_BOARD_MCKR configuration */
EFC0->EEFC_FMR = EEFC_FMR_FWS(4);
EFC1->EEFC_FMR = EEFC_FMR_FWS(4);
*AT91C_WDTC_WDMR = AT91C_WDTC_WDDIS; // disable watchdog
/* Initialize main oscillator */
if (!(*AT91C_PMC_MOR & CKGR_MOR_MOSCSEL)) {
*AT91C_PMC_MOR = SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT |
CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN;
while (!(PMC->PMC_SR & PMC_SR_MOSCXTS)) {
}
}
/* Switch to 3-20MHz Xtal oscillator */
*AT91C_PMC_MOR = SYS_CKGR_MOR_KEY_VALUE | SYS_BOARD_OSCOUNT |
CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCSEL;
while (!(PMC->PMC_SR & PMC_SR_MOSCSELS)) {
}
PMC->PMC_MCKR = (PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk) |
PMC_MCKR_CSS_MAIN_CLK;
while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) {
}
/* Initialize PLLA */
PMC->CKGR_PLLAR = SYS_BOARD_PLLAR;
while (!(PMC->PMC_SR & PMC_SR_LOCKA)) {
}
/* Switch to main clock */
PMC->PMC_MCKR = (SYS_BOARD_MCKR & ~PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK;
while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) {
}
/* Switch to PLLA */
PMC->PMC_MCKR = SYS_BOARD_MCKR;
while (!(PMC->PMC_SR & PMC_SR_MCKRDY)) {
}
SystemCoreClock = CHIP_FREQ_CPU_MAX;
}
void system_init_flash(uint32_t ul_clk)
{
/* Set FWS for embedded Flash access according to operating frequency */
if (ul_clk < CHIP_FREQ_FWS_0) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(0);
EFC1->EEFC_FMR = EEFC_FMR_FWS(0);
} else if (ul_clk < CHIP_FREQ_FWS_1) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(1);
EFC1->EEFC_FMR = EEFC_FMR_FWS(1);
} else if (ul_clk < CHIP_FREQ_FWS_2) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(2);
EFC1->EEFC_FMR = EEFC_FMR_FWS(2);
} else if (ul_clk < CHIP_FREQ_FWS_3) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(3);
EFC1->EEFC_FMR = EEFC_FMR_FWS(3);
} else if (ul_clk < CHIP_FREQ_FWS_4) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(4);
EFC1->EEFC_FMR = EEFC_FMR_FWS(4);
} else {
EFC0->EEFC_FMR = EEFC_FMR_FWS(5);
EFC1->EEFC_FMR = EEFC_FMR_FWS(5);
}
}
/* @cond 0 */
/**INDENT-OFF**/
#ifdef __cplusplus
}
#endif
/**INDENT-ON**/
/* @endcond */