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Arduino/hardware/sam/system/libsam/source/adc.c

321 lines
9.2 KiB
C

/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* Copyright (c) 2009, Atmel Corporation
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the disclaimer below.
*
* Atmel's name may not be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* ----------------------------------------------------------------------------
*/
/** \addtogroup adc_module Working with ADC
* The ADC driver provides the interface to configure and use the ADC peripheral.
* \n
*
* It converts the analog input to digital format. The converted result could be
* 12bit or 10bit. The ADC supports up to 16 analog lines.
*
* To Enable a ADC conversion,the user has to follow these few steps:
* <ul>
* <li> Select an appropriate reference voltage on ADVREF </li>
* <li> Configure the ADC according to its requirements and special needs,which
* could be broken down into several parts:
* -# Select the resolution by setting or clearing ADC_MR_LOWRES bit in
* ADC_MR (Mode Register)
* -# Set ADC clock by setting ADC_MR_PRESCAL bits in ADC_MR, the clock is
* calculated with ADCClock = MCK / ( (PRESCAL+1) * 2 )
* -# Set Startup Time,Tracking Clock cycles and Transfer Clock respectively
* in ADC_MR.
</li>
* <li> Start conversion by setting ADC_CR_START in ADC_CR. </li>
* </ul>
*
* For more accurate information, please look at the ADC section of the
* Datasheet.
*
* Related files :\n
* \ref adc.c\n
* \ref adc.h\n
*/
/*@{*/
/*@}*/
/**
* \file
*
* Implementation of Analog-to-Digital Converter (ADC).
*
*/
/*----------------------------------------------------------------------------
* Headers
*----------------------------------------------------------------------------*/
#include "chip.h"
/*----------------------------------------------------------------------------
* Exported functions
*----------------------------------------------------------------------------*/
/**
* \brief Initialize the ADC controller
*
* \param pAdc Pointer to an Adc instance.
* \param idAdc ADC Index
* \param trgEn trigger mode, software or Hardware
* \param trgSel hardware trigger selection
* \param sleepMode sleep mode selection
* \param resolution resolution selection 10 bits or 12 bits
* \param mckClock value of MCK in Hz
* \param adcClock value of the ADC clock in Hz
* \param startup value of the start up time (in ADCClock) (see datasheet)
* \param tracking Tracking Time (in ADCClock cycle)
*/
extern void ADC_Initialize( Adc* pAdc, uint32_t idAdc )
{
/* Enable peripheral clock*/
PMC->PMC_PCER0 = 1 << idAdc;
/* Reset the controller */
pAdc->ADC_CR = ADC_CR_SWRST;
/* Reset Mode Register set to default */
/* TrackTime set to 0 */
/* Transfer set to 1 */
/* settling set to 3 */
pAdc->ADC_MR = ADC_MR_TRANSFER(1) | ADC_MR_TRACKTIM(0) | ADC_MR_SETTLING(3);
}
/**
* \brief Initialize the ADC Timing
*/
extern void ADC_CfgTiming( Adc* pAdc, uint32_t tracking, uint32_t settling, uint32_t transfer )
{
pAdc->ADC_MR = ADC_MR_TRANSFER( transfer )
| ADC_MR_SETTLING( settling )
| ADC_MR_TRACKTIM( tracking ) ;
}
/**
* \brief Initialize the ADC Timing
*/
extern void ADC_cfgFrequency( Adc* pAdc, uint32_t startup, uint32_t prescal )
{
pAdc->ADC_MR |= ADC_MR_PRESCAL( prescal )
| ( (startup<<ADC_MR_STARTUP_Pos) & ADC_MR_STARTUP_Msk);
}
/**
* \brief Initialize the ADC Trigering
*/
extern void ADC_CfgTrigering( Adc* pAdc, uint32_t trgEn, uint32_t trgSel, uint32_t freeRun )
{
pAdc->ADC_MR |= ((trgEn<<0) & ADC_MR_TRGEN)
| ((trgSel<<ADC_MR_TRGSEL_Pos) & ADC_MR_TRGSEL_Msk)
| ((freeRun<<7) & ADC_MR_FREERUN) ;
}
/**
* \brief Initialize the ADC Low Res
*/
extern void ADC_CfgLowRes( Adc* pAdc, uint32_t resolution )
{
pAdc->ADC_MR |= (resolution<<4) & ADC_MR_LOWRES;
}
/**
* \brief Initialize the ADC PowerSave
*/
extern void ADC_CfgPowerSave( Adc* pAdc, uint32_t sleep, uint32_t fwup )
{
pAdc->ADC_MR |= ( ((sleep<<5) & ADC_MR_SLEEP)
| ((fwup<<6) & ADC_MR_FWUP) );
}
/**
* \brief Initialize the ADC Channel Mode
*/
extern void ADC_CfgChannelMode( Adc* pAdc, uint32_t useq, uint32_t anach )
{
pAdc->ADC_MR |= ( ((anach<<23) & ADC_MR_ANACH)
| ((useq <<31) & (uint32_t)ADC_MR_USEQ) );
}
/**
* \brief calcul_startup
*/
static uint32_t calcul_startup( uint32_t dwStartup )
{
static uint32_t adwValue[16]={ 0, 8, 16, 24, 64, 80, 96, 112, 512, 576, 640, 704, 768, 832, 896, 960 } ;
assert( dwStartup < sizeof( adwValue )/sizeof( adwValue[0] ) ) ;
return adwValue[dwStartup] ;
}
/**
* Return the Channel Converted Data
*
* \param pAdc Pointer to an Adc instance.
* \param channel channel to get converted value
*/
extern uint32_t ADC_GetConvertedData( Adc* pAdc, uint32_t dwChannel )
{
uint32_t dwData = 0;
assert( dwChannel < 16 ) ;
if ( 15 >= dwChannel )
{
dwData=*(pAdc->ADC_CDR+dwChannel) ;
}
return dwData ;
}
/**
* Set compare channel
*
* \param pAdc Pointer to an Adc instance.
* \param channel channel number to be set,16 for all channels
*/
extern void ADC_SetCompareChannel( Adc* pAdc, uint32_t dwChannel )
{
assert( dwChannel <= 16 ) ;
if ( dwChannel < 16 )
{
pAdc->ADC_EMR &= (uint32_t)~(ADC_EMR_CMPALL);
pAdc->ADC_EMR &= (uint32_t)~(ADC_EMR_CMPSEL_Msk);
pAdc->ADC_EMR |= (dwChannel << ADC_EMR_CMPSEL_Pos);
}
else
{
pAdc->ADC_EMR |= ADC_EMR_CMPALL;
}
}
/**
* Set compare mode
*
* \param pAdc Pointer to an Adc instance.
* \param mode compare mode
*/
extern void ADC_SetCompareMode( Adc* pAdc, uint32_t dwMode )
{
pAdc->ADC_EMR &= (uint32_t)~(ADC_EMR_CMPMODE_Msk);
pAdc->ADC_EMR |= (dwMode & ADC_EMR_CMPMODE_Msk) ;
}
/**
* Set comparsion window,one thereshold each time
*
* \param pAdc Pointer to an Adc instance.
* \param hi_lo Comparison Window
*/
extern void ADC_SetComparisonWindow( Adc* pAdc, uint32_t dwHi_Lo )
{
pAdc->ADC_CWR = dwHi_Lo ;
}
/**----------------------------------------------------------------------------
* Test if ADC Interrupt is Masked
*
* \param pAdc Pointer to an Adc instance.
* \param flag flag to be tested
*
* \return 1 if interrupt is masked, otherwise 0
*/
uint32_t ADC_IsInterruptMasked( Adc* pAdc, uint32_t dwFlag )
{
return (ADC_GetInterruptMaskStatus( pAdc ) & dwFlag) ;
}
/**----------------------------------------------------------------------------
* Test if ADC Status is Set
*
* \param pAdc Pointer to an Adc instance.
* \param flag flag to be tested
*
* \return 1 if the staus is set; 0 otherwise
*/
extern uint32_t ADC_IsStatusSet( Adc* pAdc, uint32_t dwFlag )
{
return (ADC_GetStatus( pAdc ) & dwFlag) ;
}
/**----------------------------------------------------------------------------
* Test if ADC channel interrupt Status is Set
*
* \param adc_sr Value of SR register
* \param channel Channel to be tested
*
* \return 1 if interrupt status is set, otherwise 0
*/
extern uint32_t ADC_IsChannelInterruptStatusSet( uint32_t dwAdc_sr, uint32_t dwChannel )
{
uint32_t dwStatus ;
if ( (dwAdc_sr & ((uint32_t)1 << dwChannel)) == ((uint32_t)1 << dwChannel) )
{
dwStatus = 1 ;
}
else
{
dwStatus = 0 ;
}
return dwStatus ;
}
/**
* \brief Read converted data through PDC channel
*
* \param pADC the pointer of adc peripheral
* \param pBuffer the destination buffer
* \param dwSize the size of the buffer
*/
extern uint32_t ADC_ReadBuffer( Adc* pADC, int16_t *pwBuffer, uint32_t dwSize )
{
/* Check if the first PDC bank is free*/
if ( (pADC->ADC_RCR == 0) && (pADC->ADC_RNCR == 0) )
{
pADC->ADC_RPR = (uint32_t)pwBuffer ;
pADC->ADC_RCR = dwSize ;
pADC->ADC_PTCR = ADC_PTCR_RXTEN;
return 1;
}
/* Check if the second PDC bank is free*/
else
{
if ( pADC->ADC_RNCR == 0 )
{
pADC->ADC_RNPR = (uint32_t)pwBuffer ;
pADC->ADC_RNCR = dwSize ;
return 1 ;
}
else
{
return 0 ;
}
}
}