/**************************************************************************//**
* @file
* @brief Operational Amplifier (OPAMP) peripheral API for EFM32.
* @author Energy Micro AS
* @version 2.3.2
******************************************************************************
* @section License
* (C) Copyright 2011 Energy Micro AS, http://www.energymicro.com
******************************************************************************
*
* This source code is the property of Energy Micro AS. The source and compiled
* code may only be used on Energy Micro "EFM32" microcontrollers.
*
* This copyright notice may not be removed from the source code nor changed.
*
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
* obligation to support this Software. Energy Micro AS is providing the
* Software "AS IS", with no express or implied warranties of any kind,
* including, but not limited to, any implied warranties of merchantability
* or fitness for any particular purpose or warranties against infringement
* of any proprietary rights of a third party.
*
* Energy Micro AS will not be liable for any consequential, incidental, or
* special damages, or any other relief, or for any claim by any third party,
* arising from your use of this Software.
*
*****************************************************************************/
#include "efm32.h"
#if defined( OPAMP_PRESENT ) && ( OPAMP_COUNT == 1 )
#include "efm32_system.h"
#include "efm32_assert.h"
#include "efm32_opamp.h"
/***************************************************************************//**
* @addtogroup EFM32_Library
* @{
******************************************************************************/
/***************************************************************************//**
* @addtogroup OPAMP
* @brief Operational Amplifier (OPAMP) peripheral API for EFM32.
* @details
* This module contains functions to:
* @li OPAMP_Enable() Configure and enable an opamp.
* @li OPAMP_Disable() Disable an opamp.
*
* All OPAMP functions assume that the DAC clock is running. If the DAC is not
* used, the clock can be turned off when the opamp's are configured.
*
* If the available gain values dont suit the application at hand, the resistor
* ladders can be disabled and external gain programming resistors used.
*
* A number of predefined opamp setup macros are available for configuration
* of the most common opamp topologies (see figures below).
*
* @note
* The terms POSPAD and NEGPAD in the figures are used to indicate that these
* pads should be connected to a suitable signal ground.
*
* \nUnity gain voltage follower.\n
* Use predefined macros @ref OPA_INIT_UNITY_GAIN and
* @ref OPA_INIT_UNITY_GAIN_OPA2.
* @verbatim
|\
___________|+\
| \_______
___|_ / |
| | / |
| |/ |
|___________|
@endverbatim
*
* \nNon-inverting amplifier.\n
* Use predefined macros @ref OPA_INIT_NON_INVERTING and
* @ref OPA_INIT_NON_INVERTING_OPA2.
* @verbatim
|\
___________|+\
| \_______
___|_ / |
| | / |
| |/ |
|_____R2____|
|
R1
|
NEGPAD @endverbatim
*
* \nInverting amplifier.\n
* Use predefined macros @ref OPA_INIT_INVERTING and
* @ref OPA_INIT_INVERTING_OPA2.
* @verbatim
_____R2____
| |
| |\ |
____R1_|___|_\ |
| \____|___
___| /
| |+/
| |/
|
POSPAD @endverbatim
*
* \nCascaded non-inverting amplifiers.\n
* Use predefined macros @ref OPA_INIT_CASCADED_NON_INVERTING_OPA0,
* @ref OPA_INIT_CASCADED_NON_INVERTING_OPA1 and
* @ref OPA_INIT_CASCADED_NON_INVERTING_OPA2.
* @verbatim
|\ |\ |\
___________|+\ OPA0 ___________|+\ OPA1 ___________|+\ OPA2
| \_________| | \_________| | \_______
___|_ / | ___|_ / | ___|_ / |
| | / | | | / | | | / |
| |/ | | |/ | | |/ |
|_____R2____| |_____R2____| |_____R2____|
| | |
R1 R1 R1
| | |
NEGPAD NEGPAD NEGPAD @endverbatim
*
* \nCascaded inverting amplifiers.\n
* Use predefined macros @ref OPA_INIT_CASCADED_INVERTING_OPA0,
* @ref OPA_INIT_CASCADED_INVERTING_OPA1 and
* @ref OPA_INIT_CASCADED_INVERTING_OPA2.
* @verbatim
_____R2____ _____R2____ _____R2____
| | | | | |
| |\ | | |\ | | |\ |
____R1_|___|_\ | ____R1_|___|_\ | ____R1_|___|_\ |
| \____|____| | \____|___| | \____|__
___| / ___| / ___| /
| |+/ OPA0 | |+/ OPA1 | |+/ OPA2
| |/ | |/ | |/
| | |
POSPAD POSPAD POSPAD @endverbatim
*
* \nDifferential driver with two opamp's.\n
* Use predefined macros @ref OPA_INIT_DIFF_DRIVER_OPA0 and
* @ref OPA_INIT_DIFF_DRIVER_OPA1.
* @verbatim
__________________________
| +
| _____R2____
|\ | | |
___________|+\ OPA0 | | |\ OPA1 |
| \_________|____R1_|___|_\ | _
___|_ / | | \____|______
| | / | ___| /
| |/ | | |+/
|________________| | |/
|
POSPAD @endverbatim
*
* \nDifferential receiver with three opamp's.\n
* Use predefined macros @ref OPA_INIT_DIFF_RECEIVER_OPA0,
* @ref OPA_INIT_DIFF_RECEIVER_OPA1 and @ref OPA_INIT_DIFF_RECEIVER_OPA2.
* @verbatim
|\
__________|+\ OPA1
_ | \_________
___|_ / | | _____R2____
| | / | | | |
| |/ | | | |\ |
|___________| |____R1_|___|_\ |
| \____|___
|\ ____R1_ ___| /
+__________|+\ OPA0 | | |+/ OPA2
| \_________| | |/
___|_ / | R2
| | / | |
| |/ | NEGPAD OPA0
|___________|
@endverbatim
*
* @{
******************************************************************************/
/*******************************************************************************
************************** GLOBAL FUNCTIONS *******************************
******************************************************************************/
/***************************************************************************//**
* @brief
* Disable an Operational Amplifier.
*
* @param[in] dac
* Pointer to DAC peripheral register block.
*
* @param[in] opa
* Selects an OPA, valid vaules are @ref OPA0, @ref OPA1 and @ref OPA2.
******************************************************************************/
void OPAMP_Disable( DAC_TypeDef *dac, OPAMP_TypeDef opa )
{
EFM_ASSERT( DAC_REF_VALID( dac ) );
EFM_ASSERT( DAC_OPA_VALID( opa ) );
if ( opa == OPA0 )
{
dac->CH0CTRL &= ~DAC_CH0CTRL_EN;
dac->OPACTRL &= ~DAC_OPACTRL_OPA0EN;
}
else if ( opa == OPA1 )
{
dac->CH1CTRL &= ~DAC_CH1CTRL_EN;
dac->OPACTRL &= ~DAC_OPACTRL_OPA1EN;
}
else /* OPA2 */
{
dac->OPACTRL &= ~DAC_OPACTRL_OPA2EN;
}
}
/***************************************************************************//**
* @brief
* Configure and enable an Operational Amplifier.
*
* @details
*
* @param[in] dac
* Pointer to DAC peripheral register block.
*
* @param[in] opa
* Selects an OPA, valid vaules are @ref OPA0, @ref OPA1 and @ref OPA2.
*
* @param[in] init
* Pointer to a structure containing OPAMP init information.
******************************************************************************/
void OPAMP_Enable( DAC_TypeDef *dac, OPAMP_TypeDef opa, const OPAMP_Init_TypeDef *init )
{
uint32_t offset;
EFM_ASSERT( DAC_REF_VALID( dac ) );
EFM_ASSERT( DAC_OPA_VALID( opa ) );
EFM_ASSERT( init->bias <= ( _DAC_BIASPROG_BIASPROG_MASK >>
_DAC_BIASPROG_BIASPROG_SHIFT ) );
if ( opa == OPA0 )
{
EFM_ASSERT( ( init->outPen & ~_DAC_OPA0MUX_OUTPEN_MASK ) == 0 );
dac->BIASPROG = ( dac->BIASPROG
& ~( _DAC_BIASPROG_BIASPROG_MASK |
DAC_BIASPROG_HALFBIAS ) ) |
( init->bias << _DAC_BIASPROG_BIASPROG_SHIFT ) |
( init->halfBias ? DAC_BIASPROG_HALFBIAS : 0 );
if ( init->defaultOffset )
{
offset = SYSTEM_GetCalibrationValue( &dac->CAL );
dac->CAL = ( dac->CAL & ~_DAC_CAL_CH0OFFSET_MASK ) |
( offset & _DAC_CAL_CH0OFFSET_MASK );
}
else
{
EFM_ASSERT( init->offset <= ( _DAC_CAL_CH0OFFSET_MASK >>
_DAC_CAL_CH0OFFSET_SHIFT ) );
dac->CAL = ( dac->CAL & ~_DAC_CAL_CH0OFFSET_MASK ) |
( init->offset << _DAC_CAL_CH0OFFSET_SHIFT );
}
dac->OPA0MUX = (uint32_t)init->resSel |
(uint32_t)init->outMode |
init->outPen |
(uint32_t)init->resInMux |
(uint32_t)init->negSel |
(uint32_t)init->posSel |
( init->nextOut ? DAC_OPA0MUX_NEXTOUT : 0 ) |
( init->npEn ? DAC_OPA0MUX_NPEN : 0 ) |
( init->ppEn ? DAC_OPA0MUX_PPEN : 0 );
dac->CH0CTRL |= DAC_CH0CTRL_EN;
dac->OPACTRL = ( dac->OPACTRL
& ~( DAC_OPACTRL_OPA0SHORT |
_DAC_OPACTRL_OPA0LPFDIS_MASK |
DAC_OPACTRL_OPA0HCMDIS ) ) |
( init->shortInputs ? DAC_OPACTRL_OPA0SHORT : 0 ) |
( init->lpfPosPadDisable ?
DAC_OPACTRL_OPA0LPFDIS_PLPFDIS : 0 ) |
( init->lpfNegPadDisable ?
DAC_OPACTRL_OPA0LPFDIS_NLPFDIS : 0 ) |
( init->hcmDisable ? DAC_OPACTRL_OPA0HCMDIS : 0 ) |
( DAC_OPACTRL_OPA0EN );
}
else if ( opa == OPA1 )
{
EFM_ASSERT( ( init->outPen & ~_DAC_OPA1MUX_OUTPEN_MASK ) == 0 );
dac->BIASPROG = ( dac->BIASPROG
& ~( _DAC_BIASPROG_BIASPROG_MASK |
DAC_BIASPROG_HALFBIAS ) ) |
( init->bias << _DAC_BIASPROG_BIASPROG_SHIFT ) |
( init->halfBias ? DAC_BIASPROG_HALFBIAS : 0 );
if ( init->defaultOffset )
{
offset = SYSTEM_GetCalibrationValue( &dac->CAL );
dac->CAL = ( dac->CAL & ~_DAC_CAL_CH1OFFSET_MASK ) |
( offset & _DAC_CAL_CH1OFFSET_MASK );
}
else
{
EFM_ASSERT( init->offset <= ( _DAC_CAL_CH1OFFSET_MASK >>
_DAC_CAL_CH1OFFSET_SHIFT ) );
dac->CAL = ( dac->CAL & ~_DAC_CAL_CH1OFFSET_MASK ) |
( init->offset << _DAC_CAL_CH1OFFSET_SHIFT );
}
dac->OPA1MUX = (uint32_t)init->resSel |
(uint32_t)init->outMode |
init->outPen |
(uint32_t)init->resInMux |
(uint32_t)init->negSel |
(uint32_t)init->posSel |
( init->nextOut ? DAC_OPA1MUX_NEXTOUT : 0 ) |
( init->npEn ? DAC_OPA1MUX_NPEN : 0 ) |
( init->ppEn ? DAC_OPA1MUX_PPEN : 0 );
dac->CH1CTRL |= DAC_CH1CTRL_EN;
dac->OPACTRL = ( dac->OPACTRL
& ~( DAC_OPACTRL_OPA1SHORT |
_DAC_OPACTRL_OPA1LPFDIS_MASK |
DAC_OPACTRL_OPA1HCMDIS ) ) |
( init->shortInputs ? DAC_OPACTRL_OPA1SHORT : 0 ) |
( init->lpfPosPadDisable ?
DAC_OPACTRL_OPA1LPFDIS_PLPFDIS : 0 ) |
( init->lpfNegPadDisable ?
DAC_OPACTRL_OPA1LPFDIS_NLPFDIS : 0 ) |
( init->hcmDisable ? DAC_OPACTRL_OPA1HCMDIS : 0 ) |
( DAC_OPACTRL_OPA1EN );
}
else /* OPA2 */
{
EFM_ASSERT( ( init->posSel == DAC_OPA2MUX_POSSEL_DISABLE ) ||
( init->posSel == DAC_OPA2MUX_POSSEL_POSPAD ) ||
( init->posSel == DAC_OPA2MUX_POSSEL_OPA1INP ) ||
( init->posSel == DAC_OPA2MUX_POSSEL_OPATAP ) );
EFM_ASSERT( ( init->outMode & ~DAC_OPA2MUX_OUTMODE ) == 0 );
EFM_ASSERT( ( init->outPen & ~_DAC_OPA2MUX_OUTPEN_MASK ) == 0 );
dac->BIASPROG = ( dac->BIASPROG
& ~( _DAC_BIASPROG_OPA2BIASPROG_MASK |
DAC_BIASPROG_OPA2HALFBIAS ) ) |
( init->bias << _DAC_BIASPROG_OPA2BIASPROG_SHIFT ) |
( init->halfBias ? DAC_BIASPROG_OPA2HALFBIAS : 0 );
if ( init->defaultOffset )
{
offset = SYSTEM_GetCalibrationValue( &dac->OPAOFFSET );
dac->OPAOFFSET = ( dac->OPAOFFSET & ~_DAC_OPAOFFSET_OPA2OFFSET_MASK ) |
( offset & _DAC_OPAOFFSET_OPA2OFFSET_MASK );
}
else
{
EFM_ASSERT( init->offset <= ( _DAC_OPAOFFSET_OPA2OFFSET_MASK >>
_DAC_OPAOFFSET_OPA2OFFSET_SHIFT ) );
dac->CAL = ( dac->CAL & ~_DAC_OPAOFFSET_OPA2OFFSET_MASK ) |
( init->offset << _DAC_OPAOFFSET_OPA2OFFSET_SHIFT );
}
dac->OPA2MUX = (uint32_t)init->resSel |
(uint32_t)init->outMode |
init->outPen |
(uint32_t)init->resInMux |
(uint32_t)init->negSel |
(uint32_t)init->posSel |
( init->nextOut ? DAC_OPA2MUX_NEXTOUT : 0 ) |
( init->npEn ? DAC_OPA2MUX_NPEN : 0 ) |
( init->ppEn ? DAC_OPA2MUX_PPEN : 0 );
dac->OPACTRL = ( dac->OPACTRL
& ~( DAC_OPACTRL_OPA2SHORT |
_DAC_OPACTRL_OPA2LPFDIS_MASK |
DAC_OPACTRL_OPA2HCMDIS ) ) |
( init->shortInputs ? DAC_OPACTRL_OPA2SHORT : 0 ) |
( init->lpfPosPadDisable ?
DAC_OPACTRL_OPA2LPFDIS_PLPFDIS : 0 ) |
( init->lpfNegPadDisable ?
DAC_OPACTRL_OPA2LPFDIS_NLPFDIS : 0 ) |
( init->hcmDisable ? DAC_OPACTRL_OPA2HCMDIS : 0 ) |
( DAC_OPACTRL_OPA2EN );
}
}
/** @} (end addtogroup OPAMP) */
/** @} (end addtogroup EFM32_Library) */
#endif /* defined( OPAMP_PRESENT ) && ( OPAMP_COUNT == 1 ) */