554 lines
16 KiB
C
554 lines
16 KiB
C
//*****************************************************************************
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//
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// am_hal_adc.c
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//! @file
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//!
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//! @brief Functions for interfacing with the Analog to Digital Converter.
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//!
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//! @addtogroup adc2 Analog-to-Digital Converter (ADC)
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//! @ingroup apollo2hal
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//! @{
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//
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//*****************************************************************************
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//*****************************************************************************
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//
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// Copyright (c) 2017, Ambiq Micro
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// All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are met:
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//
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// 1. Redistributions of source code must retain the above copyright notice,
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// this list of conditions and the following disclaimer.
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//
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// 2. Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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//
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// 3. Neither the name of the copyright holder nor the names of its
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// contributors may be used to endorse or promote products derived from this
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// software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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// POSSIBILITY OF SUCH DAMAGE.
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//
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// This is part of revision 1.2.9 of the AmbiqSuite Development Package.
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//
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//*****************************************************************************
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#include "am_mcu_apollo.h"
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//*****************************************************************************
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//
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//! @brief Private SRAM view of temperature trims.
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//!
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//! This static SRAM union is private to the ADC HAL functions.
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//
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//*****************************************************************************
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static union
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{
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//! These trim values are loaded as uint32_t values.
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struct
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{
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//! Temperature of the package test head (in degrees Kelvin)
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uint32_t ui32CalibrationTemperature;
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//! Voltage corresponding to temperature measured on test head.
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uint32_t ui32CalibrationVoltage;
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//! ADC offset voltage measured on the package test head.
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uint32_t ui32CalibrationOffset;
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//! Flag if default (guess) or measured.
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bool bMeasured;
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} ui32;
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//! These trim values are accessed as floats when used in temp calculations.
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struct
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{
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//! Temperature of the package test head in degrees Kelvin
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float fCalibrationTemperature;
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//! Voltage corresponding to temperature measured on test head.
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float fCalibrationVoltage;
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//! ADC offset voltage measured on the package test head.
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float fCalibrationOffset;
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//! Flag if default (guess) or measured.
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float fMeasuredFlag;
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} flt;
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} priv_temp_trims;
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//*****************************************************************************
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//
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//! @brief Configure the ADC.
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//!
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//! @param psConfig - pointer to the configuration structure for the ADC.
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//!
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//! This function may be used to perform the initial setup of the ADC based on
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//! setting found in a configuration structure.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_config(am_hal_adc_config_t *psConfig)
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{
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//
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// Set general ADC configuration parameters.
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//
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AM_REG(ADC, CFG) = (psConfig->ui32Clock |
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psConfig->ui32TriggerConfig |
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psConfig->ui32Reference |
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psConfig->ui32ClockMode |
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psConfig->ui32PowerMode |
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psConfig->ui32Repeat |
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AM_REG_ADC_CFG_ADCEN(1));
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//
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// Grab the temperature trims.
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//
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priv_temp_trims.ui32.ui32CalibrationTemperature =
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am_hal_flash_load_ui32(AM_HAL_ADC_CALIB_TEMP_ADDR);
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priv_temp_trims.ui32.ui32CalibrationVoltage =
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am_hal_flash_load_ui32(AM_HAL_ADC_CALIB_AMBIENT_ADDR);
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priv_temp_trims.ui32.ui32CalibrationOffset =
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am_hal_flash_load_ui32(AM_HAL_ADC_CALIB_ADC_OFFSET_ADDR);
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if ( (priv_temp_trims.ui32.ui32CalibrationTemperature == 0xffffffff) ||
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(priv_temp_trims.ui32.ui32CalibrationVoltage == 0xffffffff) ||
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(priv_temp_trims.ui32.ui32CalibrationOffset == 0xffffffff) )
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{
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//
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// Since the device has not been calibrated on the tester, we'll load
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// default calibration values. These default values should result
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// in worst-case temperature measurements of +-6 degress C.
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//
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priv_temp_trims.flt.fCalibrationTemperature = AM_HAL_ADC_CALIB_TEMP_DEFAULT;
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priv_temp_trims.flt.fCalibrationVoltage = AM_HAL_ADC_CALIB_AMBIENT_DEFAULT;
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priv_temp_trims.flt.fCalibrationOffset = AM_HAL_ADC_CALIB_ADC_OFFSET_DEFAULT;
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priv_temp_trims.ui32.bMeasured = false;
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}
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else
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{
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priv_temp_trims.ui32.bMeasured = true;
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}
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}
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//*****************************************************************************
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//
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//! @brief Get the temperature trim parameters after configuring the ADC.
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//!
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//! @param pfTemp - pointer to a location to store the calibration temperature.
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//! @param pfVoltage - pointer to a location to store the calibration voltage.
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//! @param pfOffsetV - pointer to a location to store the calibration offset.
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//!
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//! This function may be used to access the actual temperature sensor trim
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//! values from the private structure.
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//!
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//! WARNING: only call this after the ADC has been configured with
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//! am_hal_adc_config.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_temp_trims_get(float * pfTemp, float * pfVoltage, float * pfOffsetV)
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{
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//
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// Return trim temperature as a float, if you can.
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//
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if ( pfTemp != NULL )
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{
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*pfTemp = priv_temp_trims.flt.fCalibrationTemperature;
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}
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//
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// Return trim voltage as a float, if you can.
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//
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if ( pfVoltage != NULL )
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{
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*pfVoltage = priv_temp_trims.flt.fCalibrationVoltage;
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}
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//
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// Return trim ADC offset voltage as a float, if you can.
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//
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if ( pfOffsetV != NULL )
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{
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*pfOffsetV = priv_temp_trims.flt.fCalibrationOffset;
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}
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}
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//*****************************************************************************
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//
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//! @brief Set the ADC window parameters.
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//!
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//! @param ui32Upper - the upper limit for the ADC window.
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//! @param ui32Upper - the lower limit for the ADC window.
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//!
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//! This function may be used to change the ADC window parameters. Please note
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//! that the upper and lower limits are only 16-bits wide in the ADC hardware.
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//! This function will ignore the upper 16 bits of these arguments.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_window_set(uint32_t ui32Upper, uint32_t ui32Lower)
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{
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//
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// Set the window limits for the ADC.
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//
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AM_BFW(ADC, WULIM, ULIM, ui32Upper);
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AM_BFW(ADC, WLLIM, LLIM, ui32Lower);
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}
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//*****************************************************************************
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//
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//! @brief Configure a single ADC slot.
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//!
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//! @param ui32SlotNumber - the number of the ADC slot to be configured.
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//! @param ui32SlotConfig - contains slot-specific options.
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//!
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//! This function may be used to configure the settings for an individual ADC
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//! slot. The parameter \b ui32SlotConfig should be the logical 'OR' of a slot
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//! average macro, a slot hold-time macro, a slot channel macro, and
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//! optionally, the slot window enable macro.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_slot_config(uint32_t ui32SlotNumber, uint32_t ui32SlotConfig)
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{
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uint32_t ui32RegOffset;
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//
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// Make sure we're accessing a real slot.
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//
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am_hal_debug_assert_msg((ui32SlotNumber & 0xFFFFFFFF0) == 0,
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"Trying to configure an ADC slot that doesn't exist.");
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//
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// Locate the correct register for this ADC slot.
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//
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ui32RegOffset = (AM_REG_ADCn(0) + AM_REG_ADC_SL0CFG_O + (4 * ui32SlotNumber));
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//
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// Write the register with the caller's configuration value.
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//
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AM_REGVAL(ui32RegOffset) = ui32SlotConfig;
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}
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//*****************************************************************************
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//
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//! @brief Peek at the next fifo entry.
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//!
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//! This function reads the oldest value in the ADC sample fifo but doesn't
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//! actually advance the fifo to the next entry. This function is useful when
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//! you need information from the fifo but you don't want to also empty the
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//! fifo. This could be helpful if you want to check the FIFO depth without
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//! pulling any data out.
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//!
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//! The value returned by this function is the raw 32-bit value provided by the
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//! ADC hardware. In order to interpret this value, you will need to use one of
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//! the following macros.
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//!
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//! @return 32-bit FIFO entry.
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//!
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//
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//*****************************************************************************
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uint32_t
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am_hal_adc_fifo_peek(void)
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{
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uint32_t ui32FIFOValue;
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//
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// Grab a value from the ADC FIFO.
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//
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ui32FIFOValue = AM_REG(ADC, FIFO);
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//
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// Return FIFO entry.
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//
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return ui32FIFOValue;
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}
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//*****************************************************************************
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//
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//! @brief
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//!
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//! This function reads the oldest value in the ADC fifo and then pops the
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//! fifo. Use this function when you actually want to pull data out of the
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//! fifo.
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//!
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//! @return 32-bit FIFO entry.
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//!
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//
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//*****************************************************************************
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uint32_t
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am_hal_adc_fifo_pop(void)
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{
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uint32_t ui32FIFOValue;
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//
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// Grab a value from the ADC FIFO.
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//
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ui32FIFOValue = AM_REG(ADC, FIFO);
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//
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// Pop the FIFO.
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//
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AM_REG(ADC, FIFO) = 0;
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//
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// Return FIFO valid bits.
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//
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return ui32FIFOValue;
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}
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//*****************************************************************************
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//
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//! @brief Issue Software Trigger to the ADC.
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//!
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//! This function issues the software trigger to the ADC.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_trigger(void)
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{
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//
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// Write to the Software trigger register in the ADC.
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//
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AM_REG(ADC, SWT) = 0x37;
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}
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//*****************************************************************************
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//
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//! @brief Enable the ADC.
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//!
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//! Use this function to enable the ADC.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_enable(void)
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{
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//
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// Enable the ADC.
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//
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AM_BFW(ADC, CFG, ADCEN, 0x1);
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}
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//*****************************************************************************
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//
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//! @brief Disable the ADC.
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//!
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//! Use this function to disable the ADC.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_disable(void)
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{
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//
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// Disable the ADC.
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//
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AM_BFW(ADC, CFG, ADCEN, 0x0);
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}
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//*****************************************************************************
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//
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//! @brief Enable selected ADC Interrupts.
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//!
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//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
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//!
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//! Use this function to enable the ADC interrupts.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_int_enable(uint32_t ui32Interrupt)
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{
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//
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// Enable the interrupts.
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//
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AM_REG(ADC, INTEN) |= ui32Interrupt;
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}
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//*****************************************************************************
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//
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//! @brief Return enabled ADC Interrupts.
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//!
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//! Use this function to get all enabled ADC interrupts.
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//!
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//! @return enabled ADC Interrupts.
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//
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//*****************************************************************************
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uint32_t
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am_hal_adc_int_enable_get(void)
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{
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//
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// Return enabled interrupts.
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//
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return AM_REG(ADC, INTEN);
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}
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//*****************************************************************************
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//
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//! @brief Disable selected ADC Interrupts.
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//!
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//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
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//!
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//! Use this function to disable the ADC interrupts.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_int_disable(uint32_t ui32Interrupt)
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{
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//
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// Disable the interrupts.
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//
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AM_REG(ADC, INTEN) &= ~ui32Interrupt;
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}
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//*****************************************************************************
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//
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//! @brief Clear selected ADC Interrupts.
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//!
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//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
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//!
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//! Use this function to clear the ADC interrupts.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_int_clear(uint32_t ui32Interrupt)
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{
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//
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// Clear the interrupts.
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//
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AM_REG(ADC, INTCLR) = ui32Interrupt;
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}
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//*****************************************************************************
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//
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//! @brief Set selected ADC Interrupts.
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//!
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//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
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//!
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//! Use this function to set the ADC interrupts.
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//!
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//! @return None.
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//
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//*****************************************************************************
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void
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am_hal_adc_int_set(uint32_t ui32Interrupt)
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{
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//
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// Set the interrupts.
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//
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AM_REG(ADC, INTSET) = ui32Interrupt;
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}
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//*****************************************************************************
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//
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//! @brief Return either enabled or raw selected ADC interrupt status.
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//!
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//! @param bEnabledOnly - return the status of only the enabled interrupts.
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//!
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//! Use this function to get the ADC interrupt status.
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//!
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//! @return enabled or raw ADC interrupt status.
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//
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//*****************************************************************************
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uint32_t
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am_hal_adc_int_status_get(bool bEnabledOnly)
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{
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//
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// Return the status.
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//
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if (bEnabledOnly)
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{
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uint32_t u32RetVal = AM_REG(ADC, INTEN);
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u32RetVal &= AM_REG(ADC, INTSTAT);
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return u32RetVal;
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}
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else
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{
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return AM_REG(ADC, INTSTAT);
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}
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}
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//*****************************************************************************
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//
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//! @brief Return temperature in degrees C of supplied voltage.
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//!
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//! @param fVoltage - return the temperature corresponding to this voltage.
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//!
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//! Use this function to convert volts from the temperature sensor into degrees
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//! C. Caller converts ADC binary code to volts based on reference used.
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//! This routine looks up the trim parameters and returns corrected temperature.
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//!
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//! The computation is based on a line running through 0 degrees K.
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//! We find the slope from the trimmed temperature calibration point.
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//!
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//!
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//! @return the temperature in degrees C.
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//
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//*****************************************************************************
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float
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am_hal_adc_volts_to_celsius(float fVoltage)
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{
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float fTemp;
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//
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// Get calibration temperature from trimmed values & convert to degrees K.
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//
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float fCalibration_temp = priv_temp_trims.flt.fCalibrationTemperature;
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//
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// Get remaining trimmed values.
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//
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float fCalibration_voltage = priv_temp_trims.flt.fCalibrationVoltage;
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float fCalibration_offset = priv_temp_trims.flt.fCalibrationOffset;
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//
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// Compute the temperature.
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//
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fTemp = fCalibration_temp;
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fTemp /= (fCalibration_voltage - fCalibration_offset);
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fTemp *= (fVoltage - fCalibration_offset);
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//
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// Give it back to the caller in Celsius.
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//
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return fTemp - 273.15f;
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}
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//*****************************************************************************
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//
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// End Doxygen group.
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//! @}
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//
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//*****************************************************************************
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