| /** | |
| * \file | |
| * | |
| * \brief Chip-specific system clock management functions | |
| * | |
| * Copyright (C) 2010 Atmel Corporation. All rights reserved. | |
| * | |
| * \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 AVR 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. | |
| */ | |
| #include <compiler.h> | |
| #include <sysclk.h> | |
| #include <osc.h> | |
| #include <pll.h> | |
| #if (CONFIG_OSC_RC32_CAL==48000000UL) | |
| #include <nvm.h> | |
| #endif | |
| void sysclk_init(void) | |
| { | |
| sysclk_set_prescalers(CONFIG_SYSCLK_PSADIV,CONFIG_SYSCLK_PSBCDIV); | |
| //* Replace osc_user_calibration(OSC_ID_RC32MHZ,cal); | |
| DFLLRC32M.CALA=0x40; | |
| DFLLRC32M.CALB=0x23; | |
| osc_enable(OSC_ID_RC32MHZ); | |
| osc_wait_ready(OSC_ID_RC32MHZ); | |
| ccp_write_io((uint8_t *)&CLK.CTRL, CONFIG_SYSCLK_SOURCE); | |
| //* Replace osc_enable_autocalibration(CONFIG_OSC_AUTOCAL,CONFIG_OSC_AUTOCAL_REF_OSC); | |
| OSC.DFLLCTRL &= ~(OSC_RC32MCREF_gm); | |
| // Calibrate 32MRC at 48MHz using USB SOF | |
| // 48MHz/1kHz=0xBB80 | |
| DFLLRC32M.COMP1=0x80; | |
| DFLLRC32M.COMP2=0xBB; | |
| OSC.DFLLCTRL |= OSC_RC32MCREF_USBSOF_gc; | |
| DFLLRC32M.CTRL |= DFLL_ENABLE_bm; | |
| } | |
| /** | |
| * \brief Enable clock for the USB module | |
| * | |
| * \pre CONFIG_USBCLK_SOURCE must be defined. | |
| * | |
| * \param freq The required USB clock frequency in MHz: | |
| * \arg \c 6 for 6 MHz | |
| * \arg \c 48 for 48 MHz | |
| */ | |
| void sysclk_enable_usb(uint8_t freq) | |
| { | |
| Assert(freq == 48); | |
| ccp_write_io((uint8_t *)&CLK.USBCTRL, 0 | |
| | CLK_USBSRC_RCOSC_gc | |
| | CLK_USBSEN_bm); | |
| } | |
| /** | |
| * \brief Disable clock for the USB module | |
| */ | |
| void sysclk_disable_usb(void) | |
| { | |
| ccp_write_io((uint8_t *)&CLK.USBCTRL, 0); | |
| } |