/* ---------------------------------------------------------------------------- | |
* ATMEL Microcontroller Software Support | |
* ---------------------------------------------------------------------------- | |
* Copyright (c) 2009, 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. | |
* ---------------------------------------------------------------------------- | |
*/ | |
/** | |
* \file | |
* | |
* Provides the low-level initialization function that called on chip startup. | |
*/ | |
/*---------------------------------------------------------------------------- | |
* Headers | |
*----------------------------------------------------------------------------*/ | |
#include "board.h" | |
/*---------------------------------------------------------------------------- | |
* Local definitions | |
*----------------------------------------------------------------------------*/ | |
/* Clock settings at 48MHz for 18 MHz crystal */ | |
#if (BOARD_MCK == 48000000) | |
#define BOARD_OSCOUNT (CKGR_MOR_MOSCXTST(0x8)) | |
#define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | |
| CKGR_PLLAR_MULA(0xc) \ | |
| CKGR_PLLAR_PLLACOUNT(0x1) \ | |
| CKGR_PLLAR_DIVA(0x5)) | |
#define BOARD_MCKR (PMC_MCKR_PRES_CLK | PMC_MCKR_CSS_PLLA_CLK) | |
/* Clock settings at 64MHz for 18 MHz crystal */ | |
#elif (BOARD_MCK == 64000000) | |
#define BOARD_OSCOUNT (CKGR_MOR_MOSCXTST(0x8)) | |
#define BOARD_PLLAR (CKGR_PLLAR_STUCKTO1 \ | |
| CKGR_PLLAR_MULA(0x06) \ | |
| CKGR_PLLAR_PLLACOUNT(0x1) \ | |
| CKGR_PLLAR_DIVA(0x2)) | |
#define BOARD_MCKR (PMC_MCKR_PRES_CLK | PMC_MCKR_CSS_PLLA_CLK) | |
#else | |
#error "No settings for current BOARD_MCK." | |
#endif | |
/* Define clock timeout */ | |
#define CLOCK_TIMEOUT 0xFFFFFFFF | |
/*---------------------------------------------------------------------------- | |
* Exported functions | |
*----------------------------------------------------------------------------*/ | |
/** | |
* \brief Performs the low-level initialization of the chip. | |
* This includes EFC and master clock configuration. | |
* It also enable a low level on the pin NRST triggers a user reset. | |
*/ | |
extern WEAK void LowLevelInit( void ) | |
{ | |
uint32_t timeout = 0; | |
/* Set 3 FWS for Embedded Flash Access */ | |
EFC->EEFC_FMR = EEFC_FMR_FWS(3); | |
/* Select external slow clock */ | |
/* if ((SUPC->SUPC_SR & SUPC_SR_OSCSEL) != SUPC_SR_OSCSEL_CRYST) | |
{ | |
SUPC->SUPC_CR = (uint32_t)(SUPC_CR_XTALSEL_CRYSTAL_SEL | SUPC_CR_KEY(0xA5)); | |
timeout = 0; | |
while (!(SUPC->SUPC_SR & SUPC_SR_OSCSEL_CRYST) ); | |
} | |
*/ | |
/* Initialize main oscillator */ | |
/* if ( !(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) ) | |
{ | |
PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | BOARD_OSCOUNT | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN; | |
timeout = 0; | |
while (!(PMC->PMC_SR & PMC_SR_MOSCXTS) && (timeout++ < CLOCK_TIMEOUT)); | |
}*/ | |
/* Switch to 3-20MHz Xtal oscillator */ | |
PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | BOARD_OSCOUNT | CKGR_MOR_MOSCRCEN | CKGR_MOR_MOSCXTEN | CKGR_MOR_MOSCSEL; | |
timeout = 0; | |
while (!(PMC->PMC_SR & PMC_SR_MOSCSELS) && (timeout++ < CLOCK_TIMEOUT)); | |
PMC->PMC_MCKR = (PMC->PMC_MCKR & ~(uint32_t)PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK; | |
for ( timeout = 0; !(PMC->PMC_SR & PMC_SR_MCKRDY) && (timeout++ < CLOCK_TIMEOUT) ; ); | |
/* Initialize PLLA */ | |
PMC->CKGR_PLLAR = BOARD_PLLAR; | |
timeout = 0; | |
while (!(PMC->PMC_SR & PMC_SR_LOCKA) && (timeout++ < CLOCK_TIMEOUT)); | |
/* Switch to main clock */ | |
PMC->PMC_MCKR = (BOARD_MCKR & ~PMC_MCKR_CSS_Msk) | PMC_MCKR_CSS_MAIN_CLK; | |
for ( timeout = 0; !(PMC->PMC_SR & PMC_SR_MCKRDY) && (timeout++ < CLOCK_TIMEOUT) ; ); | |
PMC->PMC_MCKR = BOARD_MCKR ; | |
for ( timeout = 0; !(PMC->PMC_SR & PMC_SR_MCKRDY) && (timeout++ < CLOCK_TIMEOUT) ; ); | |
} |