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/**************************************************************************//**
* @file em_opamp.c
* @brief Operational Amplifier (OPAMP) peripheral API
* @version 4.2.1
******************************************************************************
* @section License
* <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b>
*******************************************************************************
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
* obligation to support this Software. Silicon Labs 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.
*
* Silicon Labs 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 "em_opamp.h"
#if defined(OPAMP_PRESENT) && (OPAMP_COUNT == 1)
#include "em_system.h"
#include "em_assert.h"
/***************************************************************************//**
* @addtogroup EM_Library
* @{
******************************************************************************/
/***************************************************************************//**
* @addtogroup OPAMP
* @brief Operational Amplifier (OPAMP) peripheral API
* @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
* <em>The terms POSPAD and NEGPAD in the figures are used to indicate that these
* pads should be connected to a suitable signal ground.</em>
*
* \n<b>Unity gain voltage follower.</b>\n
* Use predefined macros @ref OPA_INIT_UNITY_GAIN and
* @ref OPA_INIT_UNITY_GAIN_OPA2.
* @verbatim
|\
___________|+\
| \_______
___|_ / |
| | / |
| |/ |
|___________|
@endverbatim
*
* \n<b>Non-inverting amplifier.</b>\n
* Use predefined macros @ref OPA_INIT_NON_INVERTING and
* @ref OPA_INIT_NON_INVERTING_OPA2.
* @verbatim
|\
___________|+\
| \_______
___|_ / |
| | / |
| |/ |
|_____R2____|
|
R1
|
NEGPAD @endverbatim
*
* \n<b>Inverting amplifier.</b>\n
* Use predefined macros @ref OPA_INIT_INVERTING and
* @ref OPA_INIT_INVERTING_OPA2.
* @verbatim
_____R2____
| |
| |\ |
____R1_|___|_\ |
| \____|___
___| /
| |+/
| |/
|
POSPAD @endverbatim
*
* \n<b>Cascaded non-inverting amplifiers.</b>\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
*
* \n<b>Cascaded inverting amplifiers.</b>\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
*
* \n<b>Differential driver with two opamp's.</b>\n
* Use predefined macros @ref OPA_INIT_DIFF_DRIVER_OPA0 and
* @ref OPA_INIT_DIFF_DRIVER_OPA1.
* @verbatim
__________________________
| +
| _____R2____
|\ | | |
___________|+\ OPA0 | | |\ OPA1 |
| \_________|____R1_|___|_\ | _
___|_ / | | \____|______
| | / | ___| /
| |/ | | |+/
|________________| | |/
|
POSPAD @endverbatim
*
* \n<b>Differential receiver with three opamp's.</b>\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.
*
* @note
* The value of the alternate output enable bit mask in the OPAMP_Init_TypeDef
* structure should consist of one or more of the
* DAC_OPA[opa#]MUX_OUTPEN_OUT[output#] flags
* (defined in \<part_name\>_dac.h) OR'ed together. @n @n
* For OPA0:
* @li DAC_OPA0MUX_OUTPEN_OUT0
* @li DAC_OPA0MUX_OUTPEN_OUT1
* @li DAC_OPA0MUX_OUTPEN_OUT2
* @li DAC_OPA0MUX_OUTPEN_OUT3
* @li DAC_OPA0MUX_OUTPEN_OUT4
*
* For OPA1:
* @li DAC_OPA1MUX_OUTPEN_OUT0
* @li DAC_OPA1MUX_OUTPEN_OUT1
* @li DAC_OPA1MUX_OUTPEN_OUT2
* @li DAC_OPA1MUX_OUTPEN_OUT3
* @li DAC_OPA1MUX_OUTPEN_OUT4
*
* For OPA2:
* @li DAC_OPA2MUX_OUTPEN_OUT0
* @li DAC_OPA2MUX_OUTPEN_OUT1
*
* E.g: @n
* init.outPen = DAC_OPA0MUX_OUTPEN_OUT0 | DAC_OPA0MUX_OUTPEN_OUT4;
*
* @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->OPAOFFSET = (dac->OPAOFFSET & ~_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 EM_Library) */
#endif /* defined( OPAMP_PRESENT ) && ( OPAMP_COUNT == 1 ) */