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/*! \file *********************************************************************
*
* \brief Provides the low-level initialization functions that called
* on chip startup.
*
* $asf_license$
*
* \par Purpose
*
* This file provides basic support for Cortex-M processor based
* microcontrollers.
*
* \author Atmel Corporation: http://www.atmel.com \n
* Support and FAQ: http://support.atmel.no/
*
******************************************************************************/
#include "sam3xa.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_ONE \
| 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);
/* Initialize main oscillator */
if (!(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL)) {
PMC->CKGR_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 */
PMC->CKGR_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 SystemCoreClockUpdate(void)
{
/* Determine clock frequency according to clock register values */
switch (PMC->PMC_MCKR & PMC_MCKR_CSS_Msk) {
case PMC_MCKR_CSS_SLOW_CLK: /* Slow clock */
if (SUPC->SUPC_SR & SUPC_SR_OSCSEL) {
SystemCoreClock = CHIP_FREQ_XTAL_32K;
} else {
SystemCoreClock = CHIP_FREQ_SLCK_RC;
}
break;
case PMC_MCKR_CSS_MAIN_CLK: /* Main clock */
if (PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) {
SystemCoreClock = CHIP_FREQ_XTAL_12M;
} else {
SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
switch (PMC->CKGR_MOR & CKGR_MOR_MOSCRCF_Msk) {
case CKGR_MOR_MOSCRCF_4_MHz:
break;
case CKGR_MOR_MOSCRCF_8_MHz:
SystemCoreClock *= 2U;
break;
case CKGR_MOR_MOSCRCF_12_MHz:
SystemCoreClock *= 3U;
break;
default:
break;
}
}
break;
case PMC_MCKR_CSS_PLLA_CLK: /* PLLA clock */
case PMC_MCKR_CSS_UPLL_CLK: /* UPLL clock */
if (PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) {
SystemCoreClock = CHIP_FREQ_XTAL_12M;
} else {
SystemCoreClock = CHIP_FREQ_MAINCK_RC_4MHZ;
switch (PMC->CKGR_MOR & CKGR_MOR_MOSCRCF_Msk) {
case CKGR_MOR_MOSCRCF_4_MHz:
break;
case CKGR_MOR_MOSCRCF_8_MHz:
SystemCoreClock *= 2U;
break;
case CKGR_MOR_MOSCRCF_12_MHz:
SystemCoreClock *= 3U;
break;
default:
break;
}
}
if ((PMC->PMC_MCKR & PMC_MCKR_CSS_Msk) == PMC_MCKR_CSS_PLLA_CLK) {
SystemCoreClock *= ((((PMC->CKGR_PLLAR) & CKGR_PLLAR_MULA_Msk) >>
CKGR_PLLAR_MULA_Pos) + 1U);
SystemCoreClock /= ((((PMC->CKGR_PLLAR) & CKGR_PLLAR_DIVA_Msk) >>
CKGR_PLLAR_DIVA_Pos));
} else {
SystemCoreClock = SYS_UTMIPLL / 2U;
}
break;
}
if ((PMC->PMC_MCKR & PMC_MCKR_PRES_Msk) == PMC_MCKR_PRES_CLK_3) {
SystemCoreClock /= 3U;
} else {
SystemCoreClock >>= ((PMC->PMC_MCKR & PMC_MCKR_PRES_Msk) >>
PMC_MCKR_PRES_Pos);
}
}
/**
* Initialize flash.
*/
void system_init_flash(uint32_t dw_clk)
{
/* Set FWS for embedded Flash access according to operating frequency */
if (dw_clk < CHIP_FREQ_FWS_0) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(0);
EFC1->EEFC_FMR = EEFC_FMR_FWS(0);
} else if (dw_clk < CHIP_FREQ_FWS_1) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(1);
EFC1->EEFC_FMR = EEFC_FMR_FWS(1);
} else if (dw_clk < CHIP_FREQ_FWS_2) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(2);
EFC1->EEFC_FMR = EEFC_FMR_FWS(2);
} else if (dw_clk < CHIP_FREQ_FWS_3) {
EFC0->EEFC_FMR = EEFC_FMR_FWS(3);
EFC1->EEFC_FMR = EEFC_FMR_FWS(3);
} else {
EFC0->EEFC_FMR = EEFC_FMR_FWS(4);
EFC1->EEFC_FMR = EEFC_FMR_FWS(4);
}
}
/* @cond 0 */
/**INDENT-OFF**/
#ifdef __cplusplus
}
#endif
/**INDENT-ON**/
/* @endcond */
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