Overview

The MCUXpresso SDK provides a peripheral driver for the Analog-to-Digital Converter (ADC12) module of MCUXpresso SDK devices.

The ADC12 driver is created to help the user better operate the ADC12 module. This driver can be considered a basic analog-to-digital converter with advanced features. The APIs for basic operations can make the ADC12 work as a general converter, which can convert the analog input to be a digital value. The APIs for advanced operations can be used as the plug-in function based on the basic operations. They can provide more ways to process the converter's conversion results, such DMA trigger, hardware compare, hardware average, and so on.

Note that channel 26 of ADC12 is connected to a internal temperature sensor of the module. If you want to get the best conversion result of the temperature value, set the field "sampleClockCount" in the structure "adc12_config_t" to be maximum value when you call the API "ADC12_Init()". This field indicates the sample time of the analog input signal. A longer sample time makes the conversion result of the analog input signal more stable and accurate.

Function groups

Initialization and deinitialization

This function group implement ADC12 initialization and deinitialization API.

Basic Operations

This function group implement basic ADC12 operation API.

Advanced Operations

This function group implement advanced ADC12 operation API.

Typical use case

Normal Configuration

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/adc12

Interrupt Configuration

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/adc12

Data Structures
struct	adc12_config_t
	Converter configuration. More...

struct	adc12_hardware_compare_config_t
	Hardware compare configuration. More...

struct	adc12_channel_config_t
	Channel conversion configuration. More...

Macros
#define	FSL_ADC12_DRIVER_VERSION (MAKE_VERSION(2, 0, 2))
	ADC12 driver version. More...

Enumerations
enum	_adc12_channel_status_flags { kADC12_ChannelConversionCompletedFlag = ADC_SC1_COCO_MASK }
	Channel status flags' mask. More...

enum	_adc12_status_flags { kADC12_ActiveFlag = ADC_SC2_ADACT_MASK, kADC12_CalibrationFailedFlag = (ADC_SC2_ADACT_MASK << 1U) }
	Converter status flags' mask. More...

enum	adc12_clock_divider_t { kADC12_ClockDivider1 = 0U, kADC12_ClockDivider2 = 1U, kADC12_ClockDivider4 = 2U, kADC12_ClockDivider8 = 3U }
	Clock divider for the converter. More...

enum	adc12_resolution_t { kADC12_Resolution8Bit = 0U, kADC12_Resolution12Bit = 1U, kADC12_Resolution10Bit = 2U }
	Converter's resolution. More...

enum	adc12_clock_source_t { kADC12_ClockSourceAlt0 = 0U, kADC12_ClockSourceAlt1 = 1U, kADC12_ClockSourceAlt2 = 2U, kADC12_ClockSourceAlt3 = 3U }
	Conversion clock source. More...

enum	adc12_reference_voltage_source_t { kADC12_ReferenceVoltageSourceVref = 0U, kADC12_ReferenceVoltageSourceValt = 1U }
	Reference voltage source. More...

enum	adc12_hardware_average_mode_t { kADC12_HardwareAverageCount4 = 0U, kADC12_HardwareAverageCount8 = 1U, kADC12_HardwareAverageCount16 = 2U, kADC12_HardwareAverageCount32 = 3U, kADC12_HardwareAverageDisabled = 4U }
	Hardware average mode. More...

enum	adc12_hardware_compare_mode_t { kADC12_HardwareCompareMode0 = 0U, kADC12_HardwareCompareMode1 = 1U, kADC12_HardwareCompareMode2 = 2U, kADC12_HardwareCompareMode3 = 3U }
	Hardware compare mode. More...

Initialization
void	ADC12_Init (ADC_Type base, const adc12_config_t config)
	Initialize the ADC12 module. More...

void	ADC12_Deinit (ADC_Type *base)
	De-initialize the ADC12 module. More...

void	ADC12_GetDefaultConfig (adc12_config_t *config)
	Gets an available pre-defined settings for converter's configuration. More...

Basic Operations
void	ADC12_SetChannelConfig (ADC_Type base, uint32_t channelGroup, const adc12_channel_config_t config)
	Configure the conversion channel. More...

static uint32_t	ADC12_GetChannelConversionValue (ADC_Type *base, uint32_t channelGroup)
	Get the conversion value. More...

uint32_t	ADC12_GetChannelStatusFlags (ADC_Type *base, uint32_t channelGroup)
	Get the status flags of channel. More...

Advanced Operations
status_t	ADC12_DoAutoCalibration (ADC_Type *base)
	Automate the hardware calibration. More...

static void	ADC12_SetOffsetValue (ADC_Type *base, uint32_t value)
	Set the offset value for the conversion result. More...

static void	ADC12_SetGainValue (ADC_Type *base, uint32_t value)
	Set the gain value for the conversion result. More...

static void	ADC12_EnableHardwareTrigger (ADC_Type *base, bool enable)
	Enable of disable the hardware trigger mode. More...

void	ADC12_SetHardwareCompareConfig (ADC_Type base, const adc12_hardware_compare_config_t config)
	Configure the hardware compare mode. More...

void	ADC12_SetHardwareAverage (ADC_Type *base, adc12_hardware_average_mode_t mode)
	Set the hardware average mode. More...

uint32_t	ADC12_GetStatusFlags (ADC_Type *base)
	Get the status flags of the converter. More...

Data Structure Documentation

struct adc12_config_t

Data Fields
adc12_reference_voltage_source_t	referenceVoltageSource
	Select the reference voltage source. More...

adc12_clock_source_t	clockSource
	Select the input clock source to converter. More...

adc12_clock_divider_t	clockDivider
	Select the divider of input clock source. More...

adc12_resolution_t	resolution
	Select the sample resolution mode. More...

uint32_t	sampleClockCount
	Select the sample clock count. More...

bool	enableContinuousConversion
	Enable continuous conversion mode. More...

Field Documentation

adc12_reference_voltage_source_t adc12_config_t::referenceVoltageSource

adc12_clock_source_t adc12_config_t::clockSource

adc12_clock_divider_t adc12_config_t::clockDivider

adc12_resolution_t adc12_config_t::resolution

uint32_t adc12_config_t::sampleClockCount

Add its value may improve the stability of the conversion result.

bool adc12_config_t::enableContinuousConversion

struct adc12_hardware_compare_config_t

Data Fields
adc12_hardware_compare_mode_t	hardwareCompareMode
	Select the hardware compare mode. More...

int16_t	value1
	Setting value1 for hardware compare mode. More...

int16_t	value2
	Setting value2 for hardware compare mode. More...

Field Documentation

adc12_hardware_compare_mode_t adc12_hardware_compare_config_t::hardwareCompareMode

int16_t adc12_hardware_compare_config_t::value1

int16_t adc12_hardware_compare_config_t::value2

struct adc12_channel_config_t

Data Fields
uint32_t	channelNumber
	Setting the conversion channel number. More...

bool	enableInterruptOnConversionCompleted
	Generate a interrupt request once the conversion is completed. More...

Field Documentation

uint32_t adc12_channel_config_t::channelNumber

The available range is 0-31. See channel connection information for each chip in Reference Manual document.

bool adc12_channel_config_t::enableInterruptOnConversionCompleted

Macro Definition Documentation

#define FSL_ADC12_DRIVER_VERSION (MAKE_VERSION(2, 0, 2))

Version 2.0.2.

Enumeration Type Documentation

enum _adc12_channel_status_flags

Enumerator
kADC12_ChannelConversionCompletedFlag	Conversion done.

enum _adc12_status_flags

Enumerator
kADC12_ActiveFlag	Converter is active.
kADC12_CalibrationFailedFlag	Calibration is failed.

enum adc12_clock_divider_t

Enumerator
kADC12_ClockDivider1	For divider 1 from the input clock to the module.
kADC12_ClockDivider2	For divider 2 from the input clock to the module.
kADC12_ClockDivider4	For divider 4 from the input clock to the module.
kADC12_ClockDivider8	For divider 8 from the input clock to the module.

enum adc12_resolution_t

Enumerator
kADC12_Resolution8Bit	8 bit resolution.
kADC12_Resolution12Bit	12 bit resolution.
kADC12_Resolution10Bit	10 bit resolution.

enum adc12_clock_source_t

Enumerator
kADC12_ClockSourceAlt0	Alternate clock 1 (ADC_ALTCLK1).
kADC12_ClockSourceAlt1	Alternate clock 2 (ADC_ALTCLK2).
kADC12_ClockSourceAlt2	Alternate clock 3 (ADC_ALTCLK3).
kADC12_ClockSourceAlt3	Alternate clock 4 (ADC_ALTCLK4).

enum adc12_reference_voltage_source_t

Enumerator
kADC12_ReferenceVoltageSourceVref	For external pins pair of VrefH and VrefL.
kADC12_ReferenceVoltageSourceValt	For alternate reference pair of ValtH and ValtL.

enum adc12_hardware_average_mode_t

Enumerator
kADC12_HardwareAverageCount4	For hardware average with 4 samples.
kADC12_HardwareAverageCount8	For hardware average with 8 samples.
kADC12_HardwareAverageCount16	For hardware average with 16 samples.
kADC12_HardwareAverageCount32	For hardware average with 32 samples.
kADC12_HardwareAverageDisabled	Disable the hardware average feature.

enum adc12_hardware_compare_mode_t

Enumerator
kADC12_HardwareCompareMode0	x < value1.
kADC12_HardwareCompareMode1	x > value1.
kADC12_HardwareCompareMode2	if value1 <= value2, then x < value1 \|\| x > value2; else, value1 > x > value2.
kADC12_HardwareCompareMode3	if value1 <= value2, then value1 <= x <= value2; else x >= value1 \|\| x <= value2.

Function Documentation

void ADC12_Init	(	ADC_Type *	base,
		const adc12_config_t *	config
	)

Parameters

base	ADC12 peripheral base address.
config	Pointer to "adc12_config_t" structure.

void ADC12_Deinit ( ADC_Type * base )

Parameters

base	ADC12 peripheral base address.

void ADC12_GetDefaultConfig ( adc12_config_t * config )

This function initializes the converter configuration structure with an available settings. The default values are:

Example:

config->referenceVoltageSource = kADC12_ReferenceVoltageSourceVref;
config->clockSource = kADC12_ClockSourceAlt0;
config->clockDivider = kADC12_ClockDivider1;
config->resolution = kADC12_Resolution8Bit;
config->sampleClockCount = 12U;
config->enableContinuousConversion = false;

Parameters

config Pointer to "adc12_config_t" structure.

void ADC12_SetChannelConfig	(	ADC_Type *	base,
		uint32_t	channelGroup,
		const adc12_channel_config_t *	config
	)

This operation triggers the conversion in software trigger mode. In hardware trigger mode, this API configures the channel while the external trigger source helps to trigger the conversion.

Note that the "Channel Group" has a detailed description. To allow sequential conversions of the ADC to be triggered by internal peripherals, the ADC can have more than one group of status and control register, one for each conversion. The channel group parameter indicates which group of registers are used, channel group 0 is for Group A registers and channel group 1 is for Group B registers. The channel groups are used in a "ping-pong" approach to control the ADC operation. At any time, only one of the channel groups is actively controlling ADC conversions. Channel group 0 is used for both software and hardware trigger modes of operation. Channel groups 1 and greater indicate potentially multiple channel group registers for use only in hardware trigger mode. See the chip configuration information in the MCU reference manual about the number of SC1n registers (channel groups) specific to this device. None of the channel groups 1 or greater are used for software trigger operation and therefore writes to these channel groups do not initiate a new conversion. Updating channel group 0 while a different channel group is actively controlling a conversion is allowed and vice versa. Writing any of the channel group registers while that specific channel group is actively controlling a conversion aborts the current conversion.

Parameters

base	ADC12 peripheral base address.
channelGroup	Channel group index.
config	Pointer to "adc12_channel_config_t" structure.

static uint32_t ADC12_GetChannelConversionValue	(	ADC_Type *	base,
		uint32_t	channelGroup
	)

inlinestatic

Parameters

base	ADC12 peripheral base address.
channelGroup	Channel group index.

Returns: Conversion value.

uint32_t ADC12_GetChannelStatusFlags	(	ADC_Type *	base,
		uint32_t	channelGroup
	)

Parameters

base	ADC12 peripheral base address.
channelGroup	Channel group index.

Returns: Flags' mask if indicated flags are asserted. See to "_adc12_channel_status_flags".

status_t ADC12_DoAutoCalibration ( ADC_Type * base )

This auto calibration helps to adjust the gain automatically according to the converter's working environment. Execute the calibration before conversion. Note that the software trigger should be used during calibration.

Note: The calibration function has bug in the SOC. The calibration failed flag may be set after calibration process even if you configure the ADC12 as the reference manual correctly. It is a known issue now and may be fixed in the future.

Parameters

base	ADC12 peripheral base address.

Return values

kStatus_Success	Calibration is done successfully.
kStatus_Fail	Calibration is failed.

static void ADC12_SetOffsetValue	(	ADC_Type *	base,
		uint32_t	value
	)

inlinestatic

This offset value takes effect on the conversion result. If the offset value is not zero, the conversion result is substracted by it.

Parameters

base	ADC12 peripheral base address.
value	Offset value.

static void ADC12_SetGainValue	(	ADC_Type *	base,
		uint32_t	value
	)

inlinestatic

This gain value takes effect on the conversion result. If the gain value is not zero, the conversion result is amplified as it.

Parameters

base	ADC12 peripheral base address.
value	Gain value.

static void ADC12_EnableHardwareTrigger	(	ADC_Type *	base,
		bool	enable
	)

inlinestatic

Parameters

base	ADC12 peripheral base address.
enable	Switcher of hardware trigger feature. "true" means to enable, "false" means not.

void ADC12_SetHardwareCompareConfig	(	ADC_Type *	base,
		const adc12_hardware_compare_config_t *	config
	)

The hardware compare mode provides a way to process the conversion result automatically by hardware. Only the result in compare range is available. To compare the range, see "adc12_hardware_compare_mode_t", or the reference manual document for more detailed information.

Parameters

base	ADC12 peripheral base address.
config	Pointer to "adc12_hardware_compare_config_t" structure. Pass "NULL" to disable the feature.

void ADC12_SetHardwareAverage	(	ADC_Type *	base,
		adc12_hardware_average_mode_t	mode
	)

Hardware average mode provides a way to process the conversion result automatically by hardware. The multiple conversion results are accumulated and averaged internally. This aids to get more accurate conversion result.

Parameters

base	ADC12 peripheral base address.
mode	Setting hardware average mode. See to "adc12_hardware_average_mode_t".

uint32_t ADC12_GetStatusFlags ( ADC_Type * base )

Parameters

base	ADC12 peripheral base address.

Returns: Flags' mask if indicated flags are asserted. See to "_adc12_status_flags".

Overview

Function groups

Initialization and deinitialization

Basic Operations

Advanced Operations

Typical use case

Normal Configuration

Interrupt Configuration

Data Structures

Macros

Enumerations

Initialization

Basic Operations

Advanced Operations

Data Structure Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Data Fields

Field Documentation

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation