295 lines
11 KiB
C
295 lines
11 KiB
C
/***************************************************************************//**
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* @file
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* @brief Analog Comparator (ACMP) peripheral module library implementation
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* for EFM32 devices.
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* @author Energy Micro AS
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* @version 2.3.2
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*******************************************************************************
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* @section License
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* <b>(C) Copyright 2010 Energy Micro AS, http://www.energymicro.com</b>
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*******************************************************************************
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*
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* This source code is the property of Energy Micro AS. The source and compiled
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* code may only be used on Energy Micro "EFM32" microcontrollers.
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*
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* This copyright notice may not be removed from the source code nor changed.
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*
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* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
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* obligation to support this Software. Energy Micro AS is providing the
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* Software "AS IS", with no express or implied warranties of any kind,
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* including, but not limited to, any implied warranties of merchantability
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* or fitness for any particular purpose or warranties against infringement
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* of any proprietary rights of a third party.
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*
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* Energy Micro AS will not be liable for any consequential, incidental, or
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* special damages, or any other relief, or for any claim by any third party,
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* arising from your use of this Software.
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*
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******************************************************************************/
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#include <stdbool.h>
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#include "efm32_acmp.h"
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#include "efm32_bitband.h"
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#include "efm32_assert.h"
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/***************************************************************************//**
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* @addtogroup EFM32_Library
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* @{
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******************************************************************************/
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/***************************************************************************//**
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* @addtogroup ACMP
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* @brief Analog comparator (ACMP) Peripheral API for EFM32
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* @{
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******************************************************************************/
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/*******************************************************************************
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******************************* DEFINES ***********************************
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******************************************************************************/
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/** @cond DO_NOT_INCLUDE_WITH_DOXYGEN */
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/** Validation of ACMP register block pointer reference
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* for assert statements. */
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#if (ACMP_COUNT == 1)
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#define ACMP_REF_VALID(ref) ((ref) == ACMP0)
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#elif (ACMP_COUNT == 2)
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#define ACMP_REF_VALID(ref) (((ref) == ACMP0) || ((ref) == ACMP1))
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#else
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#error Undefined number of analog comparators (ACMP).
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#endif
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/** @endcond */
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/*******************************************************************************
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************************** GLOBAL FUNCTIONS *******************************
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******************************************************************************/
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/***************************************************************************//**
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* @brief
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* Sets up the ACMP for use in capacative sense applications.
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*
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* @details
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* This function sets up the ACMP for use in capacacitve sense applications.
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* To use the capacative sense functionality in the ACMP you need to use
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* the PRS output of the ACMP module to count the number of oscillations
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* in the capacative sense circuit (possibly using a TIMER).
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*
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* @note
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* A basic example of capacative sensing can be found in the STK BSP
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* (capsense demo).
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*
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* @param[in] acmp
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* Pointer to ACMP peripheral register block.
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*
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* @param[in] init
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* Pointer to initialization structure used to configure ACMP for capacative
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* sensing operation.
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******************************************************************************/
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void ACMP_CapsenseInit(ACMP_TypeDef *acmp, const ACMP_CapsenseInit_TypeDef *init)
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{
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/* Make sure the module exists on the selected chip */
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EFM_ASSERT(ACMP_REF_VALID(acmp));
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/* Make sure that vddLevel is within bounds */
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EFM_ASSERT(init->vddLevel < 64);
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/* Make sure biasprog is within bounds */
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EFM_ASSERT(init->biasProg < 16);
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/* Set control register. No need to set interrupt modes */
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acmp->CTRL = (init->fullBias << _ACMP_CTRL_FULLBIAS_SHIFT)
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| (init->halfBias << _ACMP_CTRL_HALFBIAS_SHIFT)
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| (init->biasProg << _ACMP_CTRL_BIASPROG_SHIFT)
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| (init->warmTime << _ACMP_CTRL_WARMTIME_SHIFT)
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| (init->hysteresisLevel << _ACMP_CTRL_HYSTSEL_SHIFT);
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/* Select capacative sensing mode by selecting a resistor and enabling it */
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acmp->INPUTSEL = (init->resistor << _ACMP_INPUTSEL_CSRESSEL_SHIFT)
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| ACMP_INPUTSEL_CSRESEN
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| (init->lowPowerReferenceEnabled << _ACMP_INPUTSEL_LPREF_SHIFT)
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| (init->vddLevel << _ACMP_INPUTSEL_VDDLEVEL_SHIFT)
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| ACMP_INPUTSEL_NEGSEL_CAPSENSE;
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/* Enable ACMP if requested.
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* Note: BITBAND_Peripheral() function is used for setting/clearing single
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* bit peripheral register bitfields. */
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BITBAND_Peripheral(&(acmp->CTRL),
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(uint32_t)_ACMP_CTRL_EN_SHIFT,
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(uint32_t)init->enable);
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}
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/***************************************************************************//**
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* @brief
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* Sets the ACMP channel used for capacative sensing.
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*
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* @note
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* A basic example of capacative sensing can be found in the STK BSP
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* (capsense demo).
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*
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* @param[in] acmp
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* Pointer to ACMP peripheral register block.
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*
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* @param[in] channel
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* The ACMP channel to use for capacative sensing (Possel).
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******************************************************************************/
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void ACMP_CapsenseChannelSet(ACMP_TypeDef *acmp, ACMP_Channel_TypeDef channel)
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{
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/* Make sure that only external channels are used */
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EFM_ASSERT(channel < _ACMP_INPUTSEL_NEGSEL_1V25);
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/* Set channel as positive channel in ACMP */
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SET_BIT_FIELD(acmp->INPUTSEL, _ACMP_INPUTSEL_POSSEL_MASK, channel,
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_ACMP_INPUTSEL_POSSEL_SHIFT);
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}
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/***************************************************************************//**
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* @brief
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* Disables the ACMP.
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*
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* @param[in] acmp
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* Pointer to ACMP peripheral register block.
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******************************************************************************/
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void ACMP_Disable(ACMP_TypeDef *acmp)
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{
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acmp->CTRL &= ~ACMP_CTRL_EN;
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}
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/***************************************************************************//**
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* @brief
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* Enables the ACMP.
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*
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* @param[in] acmp
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* Pointer to ACMP peripheral register block.
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******************************************************************************/
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void ACMP_Enable(ACMP_TypeDef *acmp)
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{
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acmp->CTRL |= ACMP_CTRL_EN;
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}
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/***************************************************************************//**
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* @brief
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* Reset ACMP to same state as after a HW reset.
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*
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* @note
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* The ROUTE register is NOT reset by this function, in order to allow for
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* centralized setup of this feature.
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*
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* @param[in] acmp
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* Pointer to the ACMP peripheral register block.
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******************************************************************************/
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void ACMP_Reset(ACMP_TypeDef *acmp)
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{
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/* Make sure the module exists on the selected chip */
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EFM_ASSERT(ACMP_REF_VALID(acmp));
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acmp->CTRL = _ACMP_CTRL_RESETVALUE;
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acmp->INPUTSEL = _ACMP_INPUTSEL_RESETVALUE;
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acmp->IEN = _ACMP_IEN_RESETVALUE;
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acmp->IFC = _ACMP_IF_MASK;
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}
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/***************************************************************************//**
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* @brief
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* Sets up GPIO output from the ACMP.
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*
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* @note
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* GPIO must be enabled in the CMU before this function call, i.e.
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* @verbatim CMU_ClockEnable(cmuClock_GPIO, true); @endverbatim
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*
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* @param[in] acmp
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* Pointer to the ACMP peripheral register block.
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*
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* @param location
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* The pin location to use. See the datasheet for location to pin mappings.
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*
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* @param enable
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* Enable or disable pin output.
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*
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* @param invert
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* Invert output.
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******************************************************************************/
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void ACMP_GPIOSetup(ACMP_TypeDef *acmp, uint32_t location, bool enable, bool invert)
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{
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/* Sanity checking of location */
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EFM_ASSERT(location < 4);
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/* Set GPIO inversion */
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SET_BIT_FIELD(acmp->CTRL, _ACMP_CTRL_GPIOINV_MASK, invert,
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_ACMP_CTRL_GPIOINV_SHIFT);
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acmp->ROUTE = (location << _ACMP_ROUTE_LOCATION_SHIFT)
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| (enable << _ACMP_ROUTE_ACMPPEN_SHIFT);
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}
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/***************************************************************************//**
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* @brief
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* Sets which channels should be used in ACMP comparisons.
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*
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* @param[in] acmp
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* Pointer to the ACMP peripheral register block.
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*
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* @param negSel
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* Channel to use on the negative input to the ACMP.
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*
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* @param posSel
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* Channel to use on the positive input to the ACMP.
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******************************************************************************/
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void ACMP_ChannelSet(ACMP_TypeDef *acmp, ACMP_Channel_TypeDef negSel,
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ACMP_Channel_TypeDef posSel)
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{
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/* Make sure that only external channels are used as ACMP positive input */
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EFM_ASSERT(posSel < _ACMP_INPUTSEL_NEGSEL_1V25);
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/* Sanity checking of ACMP negative input */
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EFM_ASSERT(negSel <= _ACMP_INPUTSEL_NEGSEL_VDD);
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acmp->INPUTSEL = (acmp->INPUTSEL & ~(_ACMP_INPUTSEL_POSSEL_MASK |
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_ACMP_INPUTSEL_NEGSEL_MASK))
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| (negSel << _ACMP_INPUTSEL_NEGSEL_SHIFT)
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| (posSel << _ACMP_INPUTSEL_POSSEL_SHIFT);
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}
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/***************************************************************************//**
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* @brief
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*
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*
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* @param[in] acmp
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* Pointer to the ACMP peripheral register block.
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*
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* @param[in] init
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* Pointer to initialization structure used to configure ACMP for capacative
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* sensing operation.
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******************************************************************************/
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void ACMP_Init(ACMP_TypeDef *acmp, const ACMP_Init_TypeDef *init)
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{
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/* Make sure the module exists on the selected chip */
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EFM_ASSERT(ACMP_REF_VALID(acmp));
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/* Make sure biasprog is within bounds */
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EFM_ASSERT(init->biasProg < 16);
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/* Set control register. No need to set interrupt modes */
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acmp->CTRL = (init->fullBias << _ACMP_CTRL_FULLBIAS_SHIFT)
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| (init->halfBias << _ACMP_CTRL_HALFBIAS_SHIFT)
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| (init->biasProg << _ACMP_CTRL_BIASPROG_SHIFT)
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| (init->interruptOnFallingEdge << _ACMP_CTRL_IFALL_SHIFT)
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| (init->interruptOnRisingEdge << _ACMP_CTRL_IRISE_SHIFT)
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| (init->warmTime << _ACMP_CTRL_WARMTIME_SHIFT)
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| (init->hysteresisLevel << _ACMP_CTRL_HYSTSEL_SHIFT)
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| (init->inactiveValue << _ACMP_CTRL_INACTVAL_SHIFT);
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acmp->INPUTSEL = (init->lowPowerReferenceEnabled << _ACMP_INPUTSEL_LPREF_SHIFT)
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| (init->vddLevel << _ACMP_INPUTSEL_VDDLEVEL_SHIFT);
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/* Enable ACMP if requested.
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* Note: BITBAND_Peripheral() function is used for setting/clearing single
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* bit peripheral register bitfields. */
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BITBAND_Peripheral(&(acmp->CTRL),
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(uint32_t)_ACMP_CTRL_EN_SHIFT,
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(uint32_t)init->enable);
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}
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/** @} (end addtogroup ACMP) */
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/** @} (end addtogroup EFM32_Library) */
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