437 lines
12 KiB
C
437 lines
12 KiB
C
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/**
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* \file
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*
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* \brief SAM Frequency Meter (FREQM) Driver
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*
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* Copyright (C) 2015-2016 Atmel Corporation. All rights reserved.
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*
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* \asf_license_start
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*
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* \page License
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3. The name of Atmel may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* 4. This software may only be redistributed and used in connection with an
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* Atmel microcontroller product.
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*
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* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
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* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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* \asf_license_stop
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*
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*/
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/*
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* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
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*/
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#ifndef FREQM_H_INCLUDED
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#define FREQM_H_INCLUDED
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/**
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* \defgroup asfdoc_sam0_freqm_group SAM Frequency Meter (FREQM) Driver
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*
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* This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration
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* and management of the device's Frequency Meter functionality.
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*
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* The following driver API modes are covered by this manual:
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* - Polled APIs
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* \if FREQM_CALLBACK_MODE
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* - Callback APIs
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* \endif
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*
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* The following peripheral is used by this module:
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* - FREQM (Frequency Meter)
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*
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* The following devices can use this module:
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* - Atmel | SMART SAM L22
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* - Atmel | SMART SAM C20
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* - Atmel | SMART SAM C21
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*
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* The outline of this documentation is as follows:
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* - \ref asfdoc_sam0_freqm_prerequisites
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* - \ref asfdoc_sam0_freqm_module_overview
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* - \ref asfdoc_sam0_freqm_special_considerations
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* - \ref asfdoc_sam0_freqm_extra_info
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* - \ref asfdoc_sam0_freqm_examples
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* - \ref asfdoc_sam0_freqm_api_overview
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*
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*
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* \section asfdoc_sam0_freqm_prerequisites Prerequisites
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*
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* There are no prerequisites for this module.
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*
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*
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* \section asfdoc_sam0_freqm_module_overview Module Overview
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*
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* The module accurately measures the frequency of a clock by comparing it to a
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* known reference clock as soon as the FREQM is enabled. Two generic clocks are
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* used by the FREQM. The frequency of the measured clock is:
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* \f[
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* f_{CLK\_MSR} = \frac{VALUE}{REFNUM} \times f_{CLK\_REF}
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* \f]
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* Ratio can be measured with 24-bit accuracy.
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*
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* The FREQM has one interrupt source, which generates when a frequency measurement
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* is done. It can be used to wake up the device from sleep modes.
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*
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* This driver provides an interface for the FREQM functions on the device.
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*
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* \section asfdoc_sam0_freqm_special_considerations Special Considerations
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*
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* There are no special considerations for this module.
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*
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*
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* \section asfdoc_sam0_freqm_extra_info Extra Information
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*
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* For extra information see \ref asfdoc_sam0_freqm_extra. This includes:
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* - \ref asfdoc_sam0_freqm_extra_acronyms
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* - \ref asfdoc_sam0_freqm_extra_dependencies
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* - \ref asfdoc_sam0_freqm_extra_errata
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* - \ref asfdoc_sam0_freqm_extra_history
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*
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*
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* \section asfdoc_sam0_freqm_examples Examples
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*
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* For a list of examples related to this driver, see
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* \ref asfdoc_sam0_freqm_exqsg.
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*
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*
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* \section asfdoc_sam0_freqm_api_overview API Overview
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* @{
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*/
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#include <compiler.h>
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#include <system.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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#if FREQM_CALLBACK_MODE == true
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/** Forward declaration of struct */
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struct freqm_module;
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extern struct freqm_module *_freqm_instance;
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/** Type definition for a FREQM module callback function. */
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typedef void (*freqm_callback_t)(void);
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/** Enum for possible callback types for the FREQM module. */
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enum freqm_callback {
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/** Callback for measurement done */
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FREQM_CALLBACK_DONE = 0,
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/** Number of available callbacks */
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#if !defined(__DOXYGEN__)
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FREQM_CALLBACK_N,
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#endif
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};
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#endif
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/**
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* \brief FREQM software device instance structure.
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*
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* FREQM software instance structure, used to retain software state information
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* of an associated hardware module instance.
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*
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* \note The fields of this structure should not be altered by the user
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* application; they are reserved for module-internal use only.
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*/
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struct freqm_module {
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#if !defined(__DOXYGEN__)
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/** Hardware module pointer of the associated FREQM peripheral */
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Freqm *hw;
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/** The frequency of reference clock in Hz*/
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uint32_t ref_clock_freq;
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# if FREQM_CALLBACK_MODE == true
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/** Array of callbacks */
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freqm_callback_t callback[FREQM_CALLBACK_N];
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# endif
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#endif
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};
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/** Enum for the possible status types for the FREQM module. */
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enum freqm_status {
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/** FREQM measurement is finish */
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FREQM_STATUS_MEASURE_DONE = 0,
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/** FREQM measurement is ongoing or not */
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FREQM_STATUS_MEASURE_BUSY = 1,
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/** FREQM sticky count value overflow */
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FREQM_STATUS_CNT_OVERFLOW = 2,
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};
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/**
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* \brief FREQM module configuration structure.
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*
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* Configuration structure for a Frequency Meter.
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*/
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struct freqm_config {
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/** GCLK source select for measurement */
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enum gclk_generator msr_clock_source;
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/** GCLK source select for reference */
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enum gclk_generator ref_clock_source;
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/** Measurement duration in number of reference clock cycles. Range 1~255 */
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uint16_t ref_clock_circles;
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};
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/**
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* \brief Determines if the hardware module(s) are currently synchronizing to the bus.
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*
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* Checks to see if the underlying hardware peripheral module(s) are currently
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* synchronizing across multiple clock domains to the hardware bus. This
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* function can be used to delay further operations on a module until such time
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* that it is ready, to prevent blocking delays for synchronization in the
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* user application.
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*
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* \return Synchronization status of the underlying hardware module(s).
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*
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* \retval false If the module has completed synchronization
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* \retval true If the module synchronization is ongoing
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*/
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static inline bool freqm_is_syncing(void)
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{
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Freqm *const freqm_module = FREQM;
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if (freqm_module->SYNCBUSY.reg) {
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return true;
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}
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return false;
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}
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/**
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* \name Driver Initialization and Configuration
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* @{
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*/
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enum status_code freqm_init(
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struct freqm_module *const module_inst,
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Freqm *const hw,
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struct freqm_config *const config);
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/**
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* \brief Initializes all members of a FREQM configuration structure
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* to safe defaults.
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*
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* Initializes all members of a given Frequency Meter configuration
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* structure to safe known default values. This function should be called on
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* all new instances of these configuration structures before being modified
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* by the user application.
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*
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* The default configuration is as follows:
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* \li Measurement clock source is GCLK0
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* \li Reference clock source is GCLK1
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* \li Frequency Meter Reference Clock Cycles 127
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*
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* \param[in] config Configuration structure to initialize to default values
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*/
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static inline void freqm_get_config_defaults(
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struct freqm_config *const config)
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{
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/* Sanity check arguments */
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Assert(config);
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/* Default configuration values */
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config->msr_clock_source = GCLK_GENERATOR_0;
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config->ref_clock_source = GCLK_GENERATOR_1;
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config->ref_clock_circles = 127;
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}
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/**
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* \brief Enables a FREQM that was previously configured.
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*
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* Enables Frequency Meter that was previously configured via a
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* call to \ref freqm_init().
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*
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* \param[in] module_inst Software instance for the Frequency Meter peripheral
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*/
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static inline void freqm_enable(
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struct freqm_module *const module_inst)
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{
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/* Sanity check arguments */
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Assert(module_inst);
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Assert(module_inst->hw);
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Freqm *const freqm_module = module_inst->hw;
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/* Enable FREQM */
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freqm_module->CTRLA.reg |= FREQM_CTRLA_ENABLE;
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while (freqm_is_syncing()) {
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/* Wait for all hardware modules to complete synchronization */
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}
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}
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/**
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* \brief Disables a FREQM that was previously enabled.
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*
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* Disables Frequency Meter that was previously started via a call
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* to \ref freqm_enable().
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*
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* \param[in] module_inst Software instance for the Frequency Meter peripheral
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*/
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static inline void freqm_disable(
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struct freqm_module *const module_inst)
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{
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/* Sanity check arguments */
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Assert(module_inst);
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Assert(module_inst->hw);
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Freqm *const freqm_module = module_inst->hw;
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/* Disbale interrupt */
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freqm_module->INTENCLR.reg = FREQM_INTENCLR_MASK;
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/* Clear interrupt flag */
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freqm_module->INTFLAG.reg = FREQM_INTFLAG_MASK;
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/* Disable FREQM */
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freqm_module->CTRLA.reg &= ~FREQM_CTRLA_ENABLE;
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while (freqm_is_syncing()) {
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/* Wait for all hardware modules to complete synchronization */
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}
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}
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/** @} */
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/**
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* \name Read FREQM Result
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* @{
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*/
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/**
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* \brief Start a manual measurement process.
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*
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* \param[in] module Pointer to the FREQM software instance struct
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*/
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static inline void freqm_start_measure(struct freqm_module *const module)
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{
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/* Sanity check arguments */
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Assert(module);
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Assert(module->hw);
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/* Trigger measurement */
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module->hw->CTRLB.reg |= FREQM_CTRLB_START;
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}
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/**
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* \brief Clears module overflow flag.
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*
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* Clears the overflow flag of the module.
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*
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* \param[in] module Pointer to the FREQM software instance struct
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*/
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static inline void freqm_clear_overflow(struct freqm_module *const module)
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{
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/* Sanity check arguments */
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Assert(module);
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Assert(module->hw);
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/* Clear overflow flag */
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module->hw->STATUS.reg = FREQM_STATUS_OVF;
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}
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enum freqm_status freqm_get_result_value(
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struct freqm_module *const module_inst, uint32_t *result);
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/** @} */
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#ifdef __cplusplus
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}
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#endif
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/** @} */
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/**
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* \page asfdoc_sam0_freqm_extra Extra Information for FREQM Driver
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*
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* \section asfdoc_sam0_freqm_extra_acronyms Acronyms
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* Below is a table listing the acronyms used in this module, along with their
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* intended meanings.
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*
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* <table>
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* <tr>
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* <th>Acronym</th>
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* <th>Description</th>
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* </tr>
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* <tr>
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* <td>FREQM</td>
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* <td>Frequency Meter</td>
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* </tr>
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* </table>
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*
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*
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* \section asfdoc_sam0_freqm_extra_dependencies Dependencies
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* This driver has no dependencies.
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*
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*
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||
|
|
* \section asfdoc_sam0_freqm_extra_errata Errata
|
||
|
|
* There are no errata related to this driver.
|
||
|
|
*
|
||
|
|
*
|
||
|
|
* \section asfdoc_sam0_freqm_extra_history Module History
|
||
|
|
* An overview of the module history is presented in the table below, with
|
||
|
|
* details on the enhancements and fixes made to the module since its first
|
||
|
|
* release. The current version of this corresponds to the newest version in
|
||
|
|
* the table.
|
||
|
|
*
|
||
|
|
* <table>
|
||
|
|
* <tr>
|
||
|
|
* <th>Changelog</th>
|
||
|
|
* </tr>
|
||
|
|
* <tr>
|
||
|
|
* <td>Initial Release</td>
|
||
|
|
* </tr>
|
||
|
|
* </table>
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* \page asfdoc_sam0_freqm_exqsg Examples for FREQM Driver
|
||
|
|
*
|
||
|
|
* This is a list of the available Quick Start guides (QSGs) and example
|
||
|
|
* applications for \ref asfdoc_sam0_freqm_group. QSGs are simple examples with
|
||
|
|
* step-by-step instructions to configure and use this driver in a selection of
|
||
|
|
* use cases. Note that a QSG can be compiled as a standalone application or be
|
||
|
|
* added to the user application.
|
||
|
|
*
|
||
|
|
* - \subpage asfdoc_sam0_freqm_basic_use_case
|
||
|
|
* \if FREQM_CALLBACK_MODE
|
||
|
|
* - \subpage asfdoc_sam0_freqm_basic_use_case_callback
|
||
|
|
* \endif
|
||
|
|
*
|
||
|
|
* \page asfdoc_sam0_freqm_document_revision_history Document Revision History
|
||
|
|
*
|
||
|
|
* <table>
|
||
|
|
* <tr>
|
||
|
|
* <th>Doc. Rev.</td>
|
||
|
|
* <th>Date</td>
|
||
|
|
* <th>Comments</td>
|
||
|
|
* </tr>
|
||
|
|
* <tr>
|
||
|
|
* <td>42506A</td>
|
||
|
|
* <td>08/2015</td>
|
||
|
|
* <td>Initial document release</td>
|
||
|
|
* </tr>
|
||
|
|
* </table>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#endif /* FREQM_H_INCLUDED */
|
||
|
|
|