403 lines
18 KiB
C
403 lines
18 KiB
C
/**************************************************************************//**
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* @file
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* @brief Operational Amplifier (OPAMP) peripheral API for EFM32.
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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 2011 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 "efm32.h"
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#if defined( OPAMP_PRESENT ) && ( OPAMP_COUNT == 1 )
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#include "efm32_system.h"
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#include "efm32_assert.h"
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#include "efm32_opamp.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 OPAMP
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* @brief Operational Amplifier (OPAMP) peripheral API for EFM32.
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* @details
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* This module contains functions to:
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* @li OPAMP_Enable() Configure and enable an opamp.
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* @li OPAMP_Disable() Disable an opamp.
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*
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* All OPAMP functions assume that the DAC clock is running. If the DAC is not
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* used, the clock can be turned off when the opamp's are configured.
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*
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* If the available gain values dont suit the application at hand, the resistor
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* ladders can be disabled and external gain programming resistors used.
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*
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* A number of predefined opamp setup macros are available for configuration
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* of the most common opamp topologies (see figures below).
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*
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* @note
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* <em>The terms POSPAD and NEGPAD in the figures are used to indicate that these
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* pads should be connected to a suitable signal ground.</em>
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*
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* \n<b>Unity gain voltage follower.</b>\n
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* Use predefined macros @ref OPA_INIT_UNITY_GAIN and
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* @ref OPA_INIT_UNITY_GAIN_OPA2.
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* @verbatim
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___________|+\
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| \_______
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___|_ / |
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| | / |
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|___________|
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@endverbatim
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*
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* \n<b>Non-inverting amplifier.</b>\n
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* Use predefined macros @ref OPA_INIT_NON_INVERTING and
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* @ref OPA_INIT_NON_INVERTING_OPA2.
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* @verbatim
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___________|+\
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| \_______
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___|_ / |
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|_____R2____|
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R1
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NEGPAD @endverbatim
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*
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* \n<b>Inverting amplifier.</b>\n
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* Use predefined macros @ref OPA_INIT_INVERTING and
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* @ref OPA_INIT_INVERTING_OPA2.
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* @verbatim
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_____R2____
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____R1_|___|_\ |
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| \____|___
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___| /
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| |+/
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POSPAD @endverbatim
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*
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* \n<b>Cascaded non-inverting amplifiers.</b>\n
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* Use predefined macros @ref OPA_INIT_CASCADED_NON_INVERTING_OPA0,
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* @ref OPA_INIT_CASCADED_NON_INVERTING_OPA1 and
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* @ref OPA_INIT_CASCADED_NON_INVERTING_OPA2.
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* @verbatim
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___________|+\ OPA0 ___________|+\ OPA1 ___________|+\ OPA2
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| \_________| | \_________| | \_______
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___|_ / | ___|_ / | ___|_ / |
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| | / | | | / | | | / |
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| |/ | | |/ | | |/ |
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|_____R2____| |_____R2____| |_____R2____|
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R1 R1 R1
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NEGPAD NEGPAD NEGPAD @endverbatim
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*
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* \n<b>Cascaded inverting amplifiers.</b>\n
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* Use predefined macros @ref OPA_INIT_CASCADED_INVERTING_OPA0,
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* @ref OPA_INIT_CASCADED_INVERTING_OPA1 and
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* @ref OPA_INIT_CASCADED_INVERTING_OPA2.
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* @verbatim
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_____R2____ _____R2____ _____R2____
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| |\ | | |\ | | |\ |
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____R1_|___|_\ | ____R1_|___|_\ | ____R1_|___|_\ |
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| \____|____| | \____|___| | \____|__
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___| / ___| / ___| /
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| |+/ OPA0 | |+/ OPA1 | |+/ OPA2
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| |/ | |/ | |/
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POSPAD POSPAD POSPAD @endverbatim
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*
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* \n<b>Differential driver with two opamp's.</b>\n
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* Use predefined macros @ref OPA_INIT_DIFF_DRIVER_OPA0 and
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* @ref OPA_INIT_DIFF_DRIVER_OPA1.
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* @verbatim
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__________________________
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| +
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| _____R2____
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___________|+\ OPA0 | | |\ OPA1 |
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| \_________|____R1_|___|_\ | _
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___|_ / | | \____|______
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| | / | ___| /
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| |/ | | |+/
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|________________| | |/
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POSPAD @endverbatim
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*
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* \n<b>Differential receiver with three opamp's.</b>\n
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* Use predefined macros @ref OPA_INIT_DIFF_RECEIVER_OPA0,
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* @ref OPA_INIT_DIFF_RECEIVER_OPA1 and @ref OPA_INIT_DIFF_RECEIVER_OPA2.
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* @verbatim
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__________|+\ OPA1
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_ | \_________
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___|_ / | | _____R2____
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| |/ | | | |\ |
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|___________| |____R1_|___|_\ |
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| \____|___
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|\ ____R1_ ___| /
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+__________|+\ OPA0 | | |+/ OPA2
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| \_________| | |/
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___|_ / | R2
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| |/ | NEGPAD OPA0
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|___________|
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@endverbatim
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*
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* @{
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******************************************************************************/
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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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* Disable an Operational Amplifier.
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*
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* @param[in] dac
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* Pointer to DAC peripheral register block.
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*
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* @param[in] opa
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* Selects an OPA, valid vaules are @ref OPA0, @ref OPA1 and @ref OPA2.
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******************************************************************************/
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void OPAMP_Disable( DAC_TypeDef *dac, OPAMP_TypeDef opa )
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{
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EFM_ASSERT( DAC_REF_VALID( dac ) );
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EFM_ASSERT( DAC_OPA_VALID( opa ) );
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if ( opa == OPA0 )
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{
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dac->CH0CTRL &= ~DAC_CH0CTRL_EN;
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dac->OPACTRL &= ~DAC_OPACTRL_OPA0EN;
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}
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else if ( opa == OPA1 )
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{
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dac->CH1CTRL &= ~DAC_CH1CTRL_EN;
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dac->OPACTRL &= ~DAC_OPACTRL_OPA1EN;
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}
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else /* OPA2 */
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{
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dac->OPACTRL &= ~DAC_OPACTRL_OPA2EN;
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}
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}
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/***************************************************************************//**
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* @brief
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* Configure and enable an Operational Amplifier.
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*
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* @details
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*
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* @param[in] dac
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* Pointer to DAC peripheral register block.
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*
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* @param[in] opa
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* Selects an OPA, valid vaules are @ref OPA0, @ref OPA1 and @ref OPA2.
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*
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* @param[in] init
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* Pointer to a structure containing OPAMP init information.
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******************************************************************************/
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void OPAMP_Enable( DAC_TypeDef *dac, OPAMP_TypeDef opa, const OPAMP_Init_TypeDef *init )
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{
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uint32_t offset;
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EFM_ASSERT( DAC_REF_VALID( dac ) );
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EFM_ASSERT( DAC_OPA_VALID( opa ) );
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EFM_ASSERT( init->bias <= ( _DAC_BIASPROG_BIASPROG_MASK >>
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_DAC_BIASPROG_BIASPROG_SHIFT ) );
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if ( opa == OPA0 )
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{
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EFM_ASSERT( ( init->outPen & ~_DAC_OPA0MUX_OUTPEN_MASK ) == 0 );
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dac->BIASPROG = ( dac->BIASPROG
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& ~( _DAC_BIASPROG_BIASPROG_MASK |
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DAC_BIASPROG_HALFBIAS ) ) |
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( init->bias << _DAC_BIASPROG_BIASPROG_SHIFT ) |
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( init->halfBias ? DAC_BIASPROG_HALFBIAS : 0 );
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if ( init->defaultOffset )
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{
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offset = SYSTEM_GetCalibrationValue( &dac->CAL );
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dac->CAL = ( dac->CAL & ~_DAC_CAL_CH0OFFSET_MASK ) |
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( offset & _DAC_CAL_CH0OFFSET_MASK );
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}
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else
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{
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EFM_ASSERT( init->offset <= ( _DAC_CAL_CH0OFFSET_MASK >>
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_DAC_CAL_CH0OFFSET_SHIFT ) );
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dac->CAL = ( dac->CAL & ~_DAC_CAL_CH0OFFSET_MASK ) |
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( init->offset << _DAC_CAL_CH0OFFSET_SHIFT );
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}
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dac->OPA0MUX = (uint32_t)init->resSel |
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(uint32_t)init->outMode |
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init->outPen |
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(uint32_t)init->resInMux |
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(uint32_t)init->negSel |
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(uint32_t)init->posSel |
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( init->nextOut ? DAC_OPA0MUX_NEXTOUT : 0 ) |
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( init->npEn ? DAC_OPA0MUX_NPEN : 0 ) |
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( init->ppEn ? DAC_OPA0MUX_PPEN : 0 );
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dac->CH0CTRL |= DAC_CH0CTRL_EN;
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dac->OPACTRL = ( dac->OPACTRL
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& ~( DAC_OPACTRL_OPA0SHORT |
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_DAC_OPACTRL_OPA0LPFDIS_MASK |
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DAC_OPACTRL_OPA0HCMDIS ) ) |
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( init->shortInputs ? DAC_OPACTRL_OPA0SHORT : 0 ) |
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( init->lpfPosPadDisable ?
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DAC_OPACTRL_OPA0LPFDIS_PLPFDIS : 0 ) |
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( init->lpfNegPadDisable ?
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DAC_OPACTRL_OPA0LPFDIS_NLPFDIS : 0 ) |
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( init->hcmDisable ? DAC_OPACTRL_OPA0HCMDIS : 0 ) |
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( DAC_OPACTRL_OPA0EN );
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}
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else if ( opa == OPA1 )
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{
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EFM_ASSERT( ( init->outPen & ~_DAC_OPA1MUX_OUTPEN_MASK ) == 0 );
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dac->BIASPROG = ( dac->BIASPROG
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& ~( _DAC_BIASPROG_BIASPROG_MASK |
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DAC_BIASPROG_HALFBIAS ) ) |
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( init->bias << _DAC_BIASPROG_BIASPROG_SHIFT ) |
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( init->halfBias ? DAC_BIASPROG_HALFBIAS : 0 );
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if ( init->defaultOffset )
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{
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offset = SYSTEM_GetCalibrationValue( &dac->CAL );
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dac->CAL = ( dac->CAL & ~_DAC_CAL_CH1OFFSET_MASK ) |
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( offset & _DAC_CAL_CH1OFFSET_MASK );
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}
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else
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{
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EFM_ASSERT( init->offset <= ( _DAC_CAL_CH1OFFSET_MASK >>
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_DAC_CAL_CH1OFFSET_SHIFT ) );
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dac->CAL = ( dac->CAL & ~_DAC_CAL_CH1OFFSET_MASK ) |
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( init->offset << _DAC_CAL_CH1OFFSET_SHIFT );
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}
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dac->OPA1MUX = (uint32_t)init->resSel |
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(uint32_t)init->outMode |
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init->outPen |
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(uint32_t)init->resInMux |
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(uint32_t)init->negSel |
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(uint32_t)init->posSel |
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( init->nextOut ? DAC_OPA1MUX_NEXTOUT : 0 ) |
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( init->npEn ? DAC_OPA1MUX_NPEN : 0 ) |
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( init->ppEn ? DAC_OPA1MUX_PPEN : 0 );
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dac->CH1CTRL |= DAC_CH1CTRL_EN;
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dac->OPACTRL = ( dac->OPACTRL
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& ~( DAC_OPACTRL_OPA1SHORT |
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_DAC_OPACTRL_OPA1LPFDIS_MASK |
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DAC_OPACTRL_OPA1HCMDIS ) ) |
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( init->shortInputs ? DAC_OPACTRL_OPA1SHORT : 0 ) |
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( init->lpfPosPadDisable ?
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DAC_OPACTRL_OPA1LPFDIS_PLPFDIS : 0 ) |
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( init->lpfNegPadDisable ?
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DAC_OPACTRL_OPA1LPFDIS_NLPFDIS : 0 ) |
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( init->hcmDisable ? DAC_OPACTRL_OPA1HCMDIS : 0 ) |
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( DAC_OPACTRL_OPA1EN );
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}
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else /* OPA2 */
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{
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EFM_ASSERT( ( init->posSel == DAC_OPA2MUX_POSSEL_DISABLE ) ||
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( init->posSel == DAC_OPA2MUX_POSSEL_POSPAD ) ||
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( init->posSel == DAC_OPA2MUX_POSSEL_OPA1INP ) ||
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( init->posSel == DAC_OPA2MUX_POSSEL_OPATAP ) );
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EFM_ASSERT( ( init->outMode & ~DAC_OPA2MUX_OUTMODE ) == 0 );
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EFM_ASSERT( ( init->outPen & ~_DAC_OPA2MUX_OUTPEN_MASK ) == 0 );
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dac->BIASPROG = ( dac->BIASPROG
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& ~( _DAC_BIASPROG_OPA2BIASPROG_MASK |
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DAC_BIASPROG_OPA2HALFBIAS ) ) |
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( init->bias << _DAC_BIASPROG_OPA2BIASPROG_SHIFT ) |
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( init->halfBias ? DAC_BIASPROG_OPA2HALFBIAS : 0 );
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if ( init->defaultOffset )
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{
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offset = SYSTEM_GetCalibrationValue( &dac->OPAOFFSET );
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dac->OPAOFFSET = ( dac->OPAOFFSET & ~_DAC_OPAOFFSET_OPA2OFFSET_MASK ) |
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( offset & _DAC_OPAOFFSET_OPA2OFFSET_MASK );
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}
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else
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{
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EFM_ASSERT( init->offset <= ( _DAC_OPAOFFSET_OPA2OFFSET_MASK >>
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_DAC_OPAOFFSET_OPA2OFFSET_SHIFT ) );
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dac->CAL = ( dac->CAL & ~_DAC_OPAOFFSET_OPA2OFFSET_MASK ) |
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( init->offset << _DAC_OPAOFFSET_OPA2OFFSET_SHIFT );
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}
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dac->OPA2MUX = (uint32_t)init->resSel |
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(uint32_t)init->outMode |
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init->outPen |
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(uint32_t)init->resInMux |
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(uint32_t)init->negSel |
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(uint32_t)init->posSel |
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( init->nextOut ? DAC_OPA2MUX_NEXTOUT : 0 ) |
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( init->npEn ? DAC_OPA2MUX_NPEN : 0 ) |
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( init->ppEn ? DAC_OPA2MUX_PPEN : 0 );
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dac->OPACTRL = ( dac->OPACTRL
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& ~( DAC_OPACTRL_OPA2SHORT |
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_DAC_OPACTRL_OPA2LPFDIS_MASK |
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DAC_OPACTRL_OPA2HCMDIS ) ) |
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( init->shortInputs ? DAC_OPACTRL_OPA2SHORT : 0 ) |
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( init->lpfPosPadDisable ?
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DAC_OPACTRL_OPA2LPFDIS_PLPFDIS : 0 ) |
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( init->lpfNegPadDisable ?
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DAC_OPACTRL_OPA2LPFDIS_NLPFDIS : 0 ) |
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( init->hcmDisable ? DAC_OPACTRL_OPA2HCMDIS : 0 ) |
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( DAC_OPACTRL_OPA2EN );
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}
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}
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/** @} (end addtogroup OPAMP) */
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/** @} (end addtogroup EFM32_Library) */
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#endif /* defined( OPAMP_PRESENT ) && ( OPAMP_COUNT == 1 ) */
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