| /* ---------------------------------------------------------------------------- | |
| * 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 | |
| *----------------------------------------------------------------------------*/ | |
| //#define OSC_12MHZ 12000000 | |
| // | |
| ///// MCFR Min and Max values with 32kHz RC | |
| //#define MCFR_32RC_MIN(freq) ((freq * 16)/44000) | |
| //#define MCFR_32RC_MAX(freq) ((freq * 16)/20000) | |
| /* Define clock dwTimeout */ | |
| #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 dwTimeout; | |
| /* Set 3 WS for Embedded Flash Access for 84 MHz */ | |
| EFC0->EEFC_FMR = EEFC_FMR_FWS( 3 ); | |
| EFC1->EEFC_FMR = EEFC_FMR_FWS( 3 ); | |
| /* Initialize main oscillator */ | |
| if ( !(PMC->CKGR_MOR & CKGR_MOR_MOSCSEL) ) /* Main Oscillator Selection */ | |
| { | |
| /* The Main Crystal Oscillator is enabled */ | |
| PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | |
| | CKGR_MOR_MOSCXTST(0x8) /* Main Crystal Oscillator Start-up Time: 1.4ms(datasheet) */ | |
| /* Specifies the number of Slow Clock cycles multiplied by 8 for the Main Crystal Oscillator start-up time */ | |
| | CKGR_MOR_MOSCRCEN /* Main On-Chip RC Oscillator Enable */ | |
| | CKGR_MOR_MOSCXTEN; /* Main Crystal Oscillator Enable */ | |
| /* MOSCSEL: The Main On-Chip RC Oscillator is selected */ | |
| /* MOSCRCF: The Fast RC Oscillator Frequency is at 4 MHz (default) */ | |
| /* CFDEN: The Clock Failure Detector is disabled. */ | |
| dwTimeout = 0; | |
| while ( !(PMC->PMC_SR & PMC_SR_MOSCXTS) && (dwTimeout++ < CLOCK_TIMEOUT) ); | |
| } | |
| /* Switch to 3-20MHz Xtal oscillator */ | |
| /* The Main Crystal Oscillator is enabled */ | |
| PMC->CKGR_MOR = CKGR_MOR_KEY(0x37) | |
| | CKGR_MOR_MOSCXTST(0x8) /* Main Crystal Oscillator Start-up Time: 1.4ms(datasheet) */ | |
| /* Specifies the number of Slow Clock cycles multiplied by 8 for the Main Crystal Oscillator start-up time */ | |
| | CKGR_MOR_MOSCRCEN /* Main On-Chip RC Oscillator Enable */ | |
| | CKGR_MOR_MOSCXTEN /* Main Crystal Oscillator Enable */ | |
| | CKGR_MOR_MOSCSEL; /* The Main Crystal Oscillator is selected */ | |
| /* MOSCRCF: The Fast RC Oscillator Frequency is at 4 MHz (default) */ | |
| /* CFDEN: The Clock Failure Detector is disabled. */ | |
| dwTimeout = 0; | |
| /* Wait Main XTAL Oscillator Status */ | |
| while (!(PMC->PMC_SR & PMC_SR_MOSCXTS) && (dwTimeout++ < CLOCK_TIMEOUT)); | |
| /* configure PLLA to 168 MHz */ | |
| PMC->CKGR_PLLAR = CKGR_PLLAR_STUCKTO1 | |
| | CKGR_PLLAR_MULA(13) /* PLLA Multiplier 12 MHz x (13+1) = 168 MHz */ | |
| | CKGR_PLLAR_PLLACOUNT(2) /* PLLA Counter 200µs(datasheet) */ | |
| | CKGR_PLLAR_DIVA(1); /* Divider bypassed */ | |
| dwTimeout = 0; | |
| /* Wait PLL A Lock Status */ | |
| while (!(PMC->PMC_SR & PMC_SR_LOCKA) && (dwTimeout++ < CLOCK_TIMEOUT)); | |
| PMC->PMC_MCKR = PMC_MCKR_PRES_CLK_2 /* Selected clock divided by 2 => 168/2 = 84 MHz */ | |
| | PMC_MCKR_CSS_MAIN_CLK; /* Main Clock is selected */ | |
| dwTimeout = 0; | |
| /* Wait Master Clock Status */ | |
| while (!(PMC->PMC_SR & PMC_SR_MCKRDY) && (dwTimeout++ < CLOCK_TIMEOUT)); | |
| PMC->PMC_MCKR = PMC_MCKR_PRES_CLK_2 /* Selected clock divided by 2 => 168/2 = 84 MHz */ | |
| | PMC_MCKR_CSS_PLLA_CLK; /* PLLA Clock is selected */ | |
| dwTimeout = 0; | |
| /* Wait Master Clock Status */ | |
| while (!(PMC->PMC_SR & PMC_SR_MCKRDY) && (dwTimeout++ < CLOCK_TIMEOUT)); | |
| } |