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Arduino/hardware/arduino/sam/system/libsam/source/adc10_sam3u.c
2012-01-11 13:46:51 +01:00

332 lines
8.7 KiB
C

/*! \file *********************************************************************
*
* \brief API for SAM3 Analog-to-Digital Converter (ADC/ADC12B) controller.
*
* ----------------------------------------------------------------------------
* SAM Software Package License
* ----------------------------------------------------------------------------
* Copyright (c) 2011, 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.
*
* - Compiler: IAR EWARM and CodeSourcery GCC for ARM
* - Supported devices: All SAM devices with a Analog-to-Digital Converter can be used.
* - AppNote:
*
* \author Atmel Corporation: http://www.atmel.com \n
* Support and FAQ: http://support.atmel.com/
*
*******************************************************************************/
#include "../chip.h"
/// @cond 0
/**INDENT-OFF**/
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**INDENT-ON**/
/// @endcond
#if SAM3U
/**
* \brief Initializes the given ADC with the specified ADC clock and startup time.
*
* \param p_adc Pointer to an ADC instance.
* \param dw_mck Main clock of the device (value in Hz).
* \param dw_adc_clock Analog-to-Digital conversion clock (value in Hz).
* \param ul_startuptime ADC start up time value(value in us). Please refer to the product datasheet for details.
* \param ul_offmode_startuptime ADC off mode startup Time value(value in us). Please refer to the product datasheet for details.
*
* \retval 0 The initialization operation succeeds.
* \retval others The initialization operation fails.
*/
uint32_t adc_init(Adc *p_adc, uint32_t ul_mck, uint32_t ul_adc_clock, uint32_t ul_startuptime)
{
p_adc->ADC_CR = ADC_CR_SWRST;
/* Reset Mode Register */
p_adc->ADC_MR = 0;
/* Reset PDC transfer */
p_adc->ADC_PTCR = (ADC_PTCR_RXTDIS | ADC_PTCR_TXTDIS);
p_adc->ADC_RCR = 0;
p_adc->ADC_RNCR = 0;
p_adc->ADC_TCR = 0;
p_adc->ADC_TNCR = 0;
uint32_t prescal = ul_mck/(2 * ul_adc_clock) - 1;
// check for rounding errors
if ( (ul_mck/((prescal+1)*2)) > ul_adc_clock ) {
prescal++;
ul_adc_clock = ul_mck/((prescal+1)*2);
}
uint32_t startup = ((ul_adc_clock/1000000) * ul_startuptime / 8) - 1;
p_adc->ADC_MR |= ADC_MR_PRESCAL(prescal) | ADC_MR_STARTUP(startup);
return 0;
}
/**
* \brief Configures conversion resolution.
*
* \param p_adc Pointer to an ADC instance.
* \param resolution ADC resolution.
*/
void adc_set_resolution(Adc *p_adc, adc_resolution_t resolution)
{
p_adc->ADC_MR |= (resolution<<4) & ADC_MR_LOWRES;
}
/**
* \brief Configures conversion trigger and free run mode.
*
* \param p_adc Pointer to an ADC instance.
* \param trigger Conversion trigger.
*/
void adc_configure_trigger(Adc *p_adc, adc_trigger_t trigger)
{
p_adc->ADC_MR |= trigger;
}
/**
* \brief Configures ADC power saving mode.
*
* \param p_adc Pointer to an ADC instance.
* \param uc_sleep ADC_MR_SLEEP_NORMAL keeps the ADC Core and reference voltage circuitry ON between conversions
* ADC_MR_SLEEP_SLEEP keeps the ADC Core and reference voltage circuitry OFF between conversions
* \param uc_offmode 0 Standby Mode (if Sleep Bit = 1)
* 1 Off Mode
*/
void adc_configure_power_save(Adc *p_adc, uint8_t uc_sleep, uint8_t uc_offmode)
{
p_adc->ADC_MR |= ((uc_sleep<<5) & ADC_MR_SLEEP) ;
}
/**
* \brief Configures ADC timing.
*
* \param p_adc Pointer to an ADC instance.
* \param ul_sh ADC sample and hold time = uc_sh / ADC clock.
*/
void adc_configure_timing(Adc *p_adc, uint32_t ul_sh)
{
p_adc->ADC_MR |= ADC_MR_SHTIM( ul_sh ) ;
}
/**
* \brief Starts analog-to-digital conversion.
*
* \note If one of the hardware event is selected as ADC trigger, this function can NOT start analog to digital conversion.
*
* \param p_adc Pointer to an ADC instance.
*/
void adc_start(Adc *p_adc)
{
p_adc->ADC_CR = ADC_CR_START;
}
/**
* \brief Stop analog-to-digital conversion.
* \param p_adc Pointer to an ADC instance.
*/
void adc_stop(Adc *p_adc)
{
p_adc->ADC_CR = ADC_CR_SWRST;
}
/**
* \brief Enables the specified ADC channel.
*
* \param p_adc Pointer to an ADC instance.
* \param adc_ch ADC channel number.
*/
void adc_enable_channel(Adc *p_adc, adc_channel_num_t adc_ch)
{
p_adc->ADC_CHER = 1 << adc_ch;
}
/**
* \brief Disables the specified ADC channel.
*
* \param p_adc Pointer to an ADC instance.
* \param adc_ch ADC channel number.
*/
void adc_disable_channel(Adc *p_adc, adc_channel_num_t adc_ch)
{
p_adc->ADC_CHDR = 1 << adc_ch;
}
/**
* \brief Reads the ADC channel status.
*
* \param p_adc Pointer to an ADC instance.
* \param adc_ch ADC channel number.
*
* \retval 1 means the specified channel is enabled.
* 0 means the specified channel is disabled.
*/
uint32_t adc_get_channel_status(Adc *p_adc, adc_channel_num_t adc_ch)
{
return p_adc->ADC_CHSR & (1 << adc_ch);
}
/**
* \brief Reads the ADC status.
*
* \param p_adc Pointer to an ADC instance.
*
* \retval ADC status register content.
*/
uint32_t adc_get_status(Adc *p_adc)
{
return p_adc->ADC_SR;
}
/**
* \brief Reads the ADC result data of the specified channel.
*
* \param p_adc Pointer to an ADC instance.
* \param adc_ch ADC channel number.
*
* \retval ADC data of the specified channel.
*/
uint32_t adc_get_value(Adc *p_adc, adc_channel_num_t adc_ch)
{
uint32_t dwData = 0;
if ( 15 >= adc_ch )
{
dwData=*(p_adc->ADC_CDR+adc_ch) ;
}
return dwData ;
}
/**
* \brief Reads the last ADC result data.
*
* \param p_adc Pointer to an ADC instance.
*
* \retval ADC data.
*/
uint32_t adc_get_latest_value(Adc *p_adc)
{
return p_adc->ADC_LCDR;
}
/**
* \brief Returns the actual ADC clock.
*
* \param p_adc Pointer to an ADC instance.
* \param ul_mck Main clock of the device (value in Hz).
*
* \retval 0 The actual ADC clock (value in Hz).
*/
uint32_t adc_get_actual_adc_clock(Adc *p_adc, uint32_t ul_mck)
{
uint32_t ul_adcfreq;
uint32_t ul_prescal;
/* ADCClock = MCK / ( (PRESCAL+1) * 2 ) */
ul_prescal = (( p_adc->ADC_MR & ADC_MR_PRESCAL_Msk) >> ADC_MR_PRESCAL_Pos);
ul_adcfreq = ul_mck / ((ul_prescal+1)*2);
return ul_adcfreq;
}
/**
* \brief Enables ADC interrupt(s).
*
* \param p_adc Pointer to an ADC instance.
* \param dw_source Interrupt(s) to be enabled.
*/
void adc_enable_interrupt(Adc *p_adc, uint32_t ul_source)
{
p_adc->ADC_IER = ul_source;
}
/**
* \brief Disables ADC interrupt(s).
*
* \param p_adc Pointer to an ADC instance.
* \param dw_source Interrupt(s) to be disabled.
*/
void adc_disable_interrupt(Adc *p_adc, uint32_t ul_source)
{
p_adc->ADC_IDR = ul_source;
}
/**
* \brief Reads ADC interrupt mask.
*
* \param p_adc Pointer to an ADC instance.
*
* \retval ADC interrupt status.
*/
uint32_t adc_get_interrupt_status(Adc *p_adc)
{
return p_adc->ADC_SR ;
}
/** \brief Read ADC interrupt mask.
*
* \param p_uart pointer to a UART instance.
*
* \return The interrupt mask value.
*/
uint32_t adc_get_interrupt_mask(Adc *p_adc)
{
return p_adc->ADC_IMR;
}
/**
* \brief Reads overrun status.
*
* \param p_adc Pointer to an ADC instance.
*
* \retval ADC overrun status.
*/
uint32_t adc_check_ovr(Adc *p_adc,adc_channel_num_t adc_ch)
{
return p_adc->ADC_SR & (0x01u << (adc_ch+8));
}
/**
* \brief Gets PDC registers base address.
*
* \param p_adc Pointer to an ADC instance.
*
* \retval PDC registers base for PDC driver to access.
*/
Pdc *adc_get_pdc_base(Adc *p_adc)
{
return PDC_ADC;
}
/// @cond 0
/**INDENT-OFF**/
#ifdef __cplusplus
}
#endif /* __cplusplus */
/**INDENT-ON**/
/// @endcond
#endif /* SAM3U */