ADC - Analog to Digital Converter#

Analog to Digital Converter (ADC) Peripheral API.

This module contains functions to control the ADC peripheral of Silicon Labs 32-bit MCUs and SoCs. The ADC is used to convert analog signals into a digital representation.

Modules#

ADC_Init_TypeDef

ADC_InitScanInput_TypeDef

ADC_InitScan_TypeDef

ADC_InitSingle_TypeDef

Enumerations#

enum

ADC_AcqTime_TypeDef {

adcAcqTime1 = _ADC_SINGLECTRL_AT_1CYCLE

adcAcqTime2 = _ADC_SINGLECTRL_AT_2CYCLES

adcAcqTime4 = _ADC_SINGLECTRL_AT_4CYCLES

adcAcqTime8 = _ADC_SINGLECTRL_AT_8CYCLES

adcAcqTime16 = _ADC_SINGLECTRL_AT_16CYCLES

adcAcqTime32 = _ADC_SINGLECTRL_AT_32CYCLES

adcAcqTime64 = _ADC_SINGLECTRL_AT_64CYCLES

adcAcqTime128 = _ADC_SINGLECTRL_AT_128CYCLES

adcAcqTime256 = _ADC_SINGLECTRL_AT_256CYCLES

}

Acquisition time (in ADC clock cycles).

enum

ADC_LPFilter_TypeDef {

adcLPFilterBypass = _ADC_CTRL_LPFMODE_BYPASS

adcLPFilterRC = _ADC_CTRL_LPFMODE_RCFILT

adcLPFilterDeCap = _ADC_CTRL_LPFMODE_DECAP

}

Lowpass filter mode.

enum

ADC_OvsRateSel_TypeDef {

adcOvsRateSel2 = _ADC_CTRL_OVSRSEL_X2

adcOvsRateSel4 = _ADC_CTRL_OVSRSEL_X4

adcOvsRateSel8 = _ADC_CTRL_OVSRSEL_X8

adcOvsRateSel16 = _ADC_CTRL_OVSRSEL_X16

adcOvsRateSel32 = _ADC_CTRL_OVSRSEL_X32

adcOvsRateSel64 = _ADC_CTRL_OVSRSEL_X64

adcOvsRateSel128 = _ADC_CTRL_OVSRSEL_X128

adcOvsRateSel256 = _ADC_CTRL_OVSRSEL_X256

adcOvsRateSel512 = _ADC_CTRL_OVSRSEL_X512

adcOvsRateSel1024 = _ADC_CTRL_OVSRSEL_X1024

adcOvsRateSel2048 = _ADC_CTRL_OVSRSEL_X2048

adcOvsRateSel4096 = _ADC_CTRL_OVSRSEL_X4096

}

Oversample rate select.

enum

ADC_PRSSEL_TypeDef {

adcPRSSELCh0 = _ADC_SINGLECTRL_PRSSEL_PRSCH0

adcPRSSELCh1 = _ADC_SINGLECTRL_PRSSEL_PRSCH1

adcPRSSELCh2 = _ADC_SINGLECTRL_PRSSEL_PRSCH2

adcPRSSELCh3 = _ADC_SINGLECTRL_PRSSEL_PRSCH3

}

Peripheral Reflex System signal used to trigger a single sample.

enum

ADC_Ref_TypeDef {

adcRef1V25 = _ADC_SINGLECTRL_REF_1V25

adcRef2V5 = _ADC_SINGLECTRL_REF_2V5

adcRefVDD = _ADC_SINGLECTRL_REF_VDD

adcRef5VDIFF = _ADC_SINGLECTRL_REF_5VDIFF

adcRefExtSingle = _ADC_SINGLECTRL_REF_EXTSINGLE

adcRef2xExtDiff = _ADC_SINGLECTRL_REF_2XEXTDIFF

adcRef2xVDD = _ADC_SINGLECTRL_REF_2XVDD

}

Single and scan mode voltage references.

enum

ADC_Res_TypeDef {

adcRes12Bit = _ADC_SINGLECTRL_RES_12BIT

adcRes8Bit = _ADC_SINGLECTRL_RES_8BIT

adcRes6Bit = _ADC_SINGLECTRL_RES_6BIT

adcResOVS = _ADC_SINGLECTRL_RES_OVS

}

Sample resolution.

enum

ADC_SingleInput_TypeDef {

adcSingleInputCh0 = _ADC_SINGLECTRL_INPUTSEL_CH0

adcSingleInputCh1 = _ADC_SINGLECTRL_INPUTSEL_CH1

adcSingleInputCh2 = _ADC_SINGLECTRL_INPUTSEL_CH2

adcSingleInputCh3 = _ADC_SINGLECTRL_INPUTSEL_CH3

adcSingleInputCh4 = _ADC_SINGLECTRL_INPUTSEL_CH4

adcSingleInputCh5 = _ADC_SINGLECTRL_INPUTSEL_CH5

adcSingleInputCh6 = _ADC_SINGLECTRL_INPUTSEL_CH6

adcSingleInputCh7 = _ADC_SINGLECTRL_INPUTSEL_CH7

adcSingleInputTemp = _ADC_SINGLECTRL_INPUTSEL_TEMP

adcSingleInputVDDDiv3 = _ADC_SINGLECTRL_INPUTSEL_VDDDIV3

adcSingleInputVDD = _ADC_SINGLECTRL_INPUTSEL_VDD

adcSingleInputVSS = _ADC_SINGLECTRL_INPUTSEL_VSS

adcSingleInputVrefDiv2 = _ADC_SINGLECTRL_INPUTSEL_VREFDIV2

adcSingleInputDACOut0 = _ADC_SINGLECTRL_INPUTSEL_DAC0OUT0

adcSingleInputDACOut1 = _ADC_SINGLECTRL_INPUTSEL_DAC0OUT1

adcSingleInputATEST = 15

adcSingleInputCh0Ch1 = _ADC_SINGLECTRL_INPUTSEL_CH0CH1

adcSingleInputCh2Ch3 = _ADC_SINGLECTRL_INPUTSEL_CH2CH3

adcSingleInputCh4Ch5 = _ADC_SINGLECTRL_INPUTSEL_CH4CH5

adcSingleInputCh6Ch7 = _ADC_SINGLECTRL_INPUTSEL_CH6CH7

adcSingleInputDiff0 = 4

}

Single sample input selection.

enum

ADC_Start_TypeDef {

adcStartSingle = ADC_CMD_SINGLESTART

adcStartScan = ADC_CMD_SCANSTART

adcStartScanAndSingle = ADC_CMD_SCANSTART | ADC_CMD_SINGLESTART

}

ADC start command.

enum

ADC_Warmup_TypeDef {

adcWarmupNormal = _ADC_CTRL_WARMUPMODE_NORMAL

adcWarmupFastBG = _ADC_CTRL_WARMUPMODE_FASTBG

adcWarmupKeepScanRefWarm = _ADC_CTRL_WARMUPMODE_KEEPSCANREFWARM

adcWarmupKeepADCWarm = _ADC_CTRL_WARMUPMODE_KEEPADCWARM

}

Warm-up mode.

Functions#

uint32_t

ADC_DataSingleGet(ADC_TypeDef *adc)

Get a single conversion result.

uint32_t

ADC_DataSinglePeek(ADC_TypeDef *adc)

Peek single conversion result.

uint32_t

ADC_DataScanGet(ADC_TypeDef *adc)

Get a scan result.

uint32_t

ADC_DataScanPeek(ADC_TypeDef *adc)

Peek scan result.

void

ADC_Init(ADC_TypeDef *adc, const ADC_Init_TypeDef *init)

Initialize ADC.

void

ADC_Reset(ADC_TypeDef *adc)

Reset ADC to a state that it was in after a hardware reset.

void

ADC_InitScan(ADC_TypeDef *adc, const ADC_InitScan_TypeDef *init)

Initialize the ADC scan sequence.

void

ADC_InitSingle(ADC_TypeDef *adc, const ADC_InitSingle_TypeDef *init)

Initialize the single ADC sample conversion.

uint8_t

ADC_TimebaseCalc(uint32_t hfperFreq)

Calculate a timebase value to get a timebase providing at least 1 us.

uint8_t

ADC_PrescaleCalc(uint32_t adcFreq, uint32_t hfperFreq)

Calculate the prescaler value used to determine the ADC clock.

void

ADC_IntClear(ADC_TypeDef *adc, uint32_t flags)

Clear one or more pending ADC interrupts.

void

ADC_IntDisable(ADC_TypeDef *adc, uint32_t flags)

Disable one or more ADC interrupts.

void

ADC_IntEnable(ADC_TypeDef *adc, uint32_t flags)

Enable one or more ADC interrupts.

uint32_t

ADC_IntGet(ADC_TypeDef *adc)

Get pending ADC interrupt flags.

uint32_t

ADC_IntGetEnabled(ADC_TypeDef *adc)

Get enabled and pending ADC interrupt flags.

void

ADC_IntSet(ADC_TypeDef *adc, uint32_t flags)

Set one or more pending ADC interrupts from software.

void

ADC_Start(ADC_TypeDef *adc, ADC_Start_TypeDef cmd)

Start scan sequence and/or single conversion.

Macros#

#define

ADC_INIT_DEFAULT undefined

Default configuration for ADC initialization structure.

#define

ADC_INITSCAN_DEFAULT undefined

Default configuration for ADC scan initialization structure.

#define

ADC_INITSINGLE_DEFAULT undefined

Default configuration for ADC single conversion initialization structure.

Enumeration Documentation#

ADC_AcqTime_TypeDef#

ADC_AcqTime_TypeDef

Acquisition time (in ADC clock cycles).

Enumerator
adcAcqTime1	1 clock cycle.
adcAcqTime2	2 clock cycles.
adcAcqTime4	4 clock cycles.
adcAcqTime8	8 clock cycles.
adcAcqTime16	16 clock cycles.
adcAcqTime32	32 clock cycles.
adcAcqTime64	64 clock cycles.
adcAcqTime128	128 clock cycles.
adcAcqTime256	256 clock cycles.

ADC_LPFilter_TypeDef#

ADC_LPFilter_TypeDef

Lowpass filter mode.

Enumerator
adcLPFilterBypass	No filter or decoupling capacitor.
adcLPFilterRC	On-chip RC filter.
adcLPFilterDeCap	On-chip decoupling capacitor.

ADC_OvsRateSel_TypeDef#

ADC_OvsRateSel_TypeDef

Oversample rate select.

Enumerator
adcOvsRateSel2	2 samples per conversion result.
adcOvsRateSel4	4 samples per conversion result.
adcOvsRateSel8	8 samples per conversion result.
adcOvsRateSel16	16 samples per conversion result.
adcOvsRateSel32	32 samples per conversion result.
adcOvsRateSel64	64 samples per conversion result.
adcOvsRateSel128	128 samples per conversion result.
adcOvsRateSel256	256 samples per conversion result.
adcOvsRateSel512	512 samples per conversion result.
adcOvsRateSel1024	1024 samples per conversion result.
adcOvsRateSel2048	2048 samples per conversion result.
adcOvsRateSel4096	4096 samples per conversion result.

ADC_PRSSEL_TypeDef#

ADC_PRSSEL_TypeDef

Peripheral Reflex System signal used to trigger a single sample.

Enumerator
adcPRSSELCh0	PRS channel 0.
adcPRSSELCh1	PRS channel 1.
adcPRSSELCh2	PRS channel 2.
adcPRSSELCh3	PRS channel 3.

ADC_Ref_TypeDef#

ADC_Ref_TypeDef

Single and scan mode voltage references.

Using unshifted enumerations and or in ADC_CTRLX_VREFSEL_REG to select the extension register CTRLX_VREFSEL. ADC Reference

Enumerator
adcRef1V25	Internal 1.25 V reference.
adcRef2V5	Internal 2.5 V reference.
adcRefVDD	Buffered VDD.
adcRef5VDIFF	Internal differential 5 V reference.
adcRefExtSingle	Single-ended external reference from pin 6.
adcRef2xExtDiff	Differential external reference from pin 6 and 7.
adcRef2xVDD	Unbuffered 2xVDD.

ADC_Res_TypeDef#

ADC_Res_TypeDef

Sample resolution.

Enumerator
adcRes12Bit	12 bit sampling.
adcRes8Bit	8 bit sampling.
adcRes6Bit	6 bit sampling.
adcResOVS	Oversampling.

ADC_SingleInput_TypeDef#

ADC_SingleInput_TypeDef

Single sample input selection.

Enumerator
adcSingleInputCh0	Channel 0.
adcSingleInputCh1	Channel 1.
adcSingleInputCh2	Channel 2.
adcSingleInputCh3	Channel 3.
adcSingleInputCh4	Channel 4.
adcSingleInputCh5	Channel 5.
adcSingleInputCh6	Channel 6.
adcSingleInputCh7	Channel 7.
adcSingleInputTemp	Temperature reference.
adcSingleInputVDDDiv3	VDD divided by 3.
adcSingleInputVDD	VDD.
adcSingleInputVSS	VSS.
adcSingleInputVrefDiv2	Vref divided by 2.
adcSingleInputDACOut0	DAC output 0.
adcSingleInputDACOut1	DAC output 1.
adcSingleInputATEST	ATEST.
adcSingleInputCh0Ch1	Positive Ch0, negative Ch1.
adcSingleInputCh2Ch3	Positive Ch2, negative Ch3.
adcSingleInputCh4Ch5	Positive Ch4, negative Ch5.
adcSingleInputCh6Ch7	Positive Ch6, negative Ch7.
adcSingleInputDiff0	Differential 0.

ADC_Start_TypeDef#

ADC_Start_TypeDef

ADC start command.

Enumerator
adcStartSingle	Start a single conversion.
adcStartScan	Start a scan sequence.
adcStartScanAndSingle	Start a scan sequence and single conversion, typically used when tailgating a single conversion after a scan sequence.

ADC_Warmup_TypeDef#

ADC_Warmup_TypeDef

Warm-up mode.

Enumerator
adcWarmupNormal	ADC shutdown after each conversion.
adcWarmupFastBG	Do not warm up bandgap references.
adcWarmupKeepScanRefWarm	Reference selected for scan mode kept warm.
adcWarmupKeepADCWarm	ADC and reference selected for scan mode kept at warmup allowing continuous conversion.

Function Documentation#

ADC_DataSingleGet#

uint32_t ADC_DataSingleGet (ADC_TypeDef * adc)

Get a single conversion result.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.

Note

Check data valid flag before calling this function.

Returns

Single conversion data.

ADC_DataSinglePeek#

uint32_t ADC_DataSinglePeek (ADC_TypeDef * adc)

Peek single conversion result.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.

Note

Check data valid flag before calling this function.

Returns

Single conversion data.

ADC_DataScanGet#

uint32_t ADC_DataScanGet (ADC_TypeDef * adc)

Get a scan result.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.

Note

Check data valid flag before calling this function.

Returns

Scan conversion data.

ADC_DataScanPeek#

uint32_t ADC_DataScanPeek (ADC_TypeDef * adc)

Peek scan result.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.

Note

Check data valid flag before calling this function.

Returns

Scan conversion data.

ADC_Init#

void ADC_Init (ADC_TypeDef * adc, const ADC_Init_TypeDef * init)

Initialize ADC.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
const ADC_Init_TypeDef *	[in]	init	A pointer to the ADC initialization structure.

Initializes common parts for both single conversion and scan sequence. In addition, single and/or scan control configuration must be done. See ADC_InitSingle() and ADC_InitScan() respectively. For ADC architectures with the ADCn->SCANINPUTSEL register, use ADC_ScanSingleEndedInputAdd() to configure single-ended scan inputs or ADC_ScanDifferentialInputAdd() to configure differential scan inputs. ADC_ScanInputClear() is also provided for applications that need to update the input configuration.

Note

This function will stop any ongoing conversion.

ADC_Reset#

void ADC_Reset (ADC_TypeDef * adc)

Reset ADC to a state that it was in after a hardware reset.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to ADC peripheral register block.

Note

The ROUTE register is NOT reset by this function to allow a centralized setup of this feature.

ADC_InitScan#

void ADC_InitScan (ADC_TypeDef * adc, const ADC_InitScan_TypeDef * init)

Initialize the ADC scan sequence.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
const ADC_InitScan_TypeDef *	[in]	init	A pointer to the ADC initialization structure.

See ADC_Start() for starting a scan sequence.

When selecting an external reference, the gain and offset calibration must be set explicitly (CAL register). For other references, the calibration is updated with values defined during manufacturing. For ADC architectures with the ADCn->SCANINPUTSEL register, use ADC_ScanSingleEndedInputAdd() to configure single-ended scan inputs or ADC_ScanDifferentialInputAdd() to configure differential scan inputs. ADC_ScanInputClear() is also provided for applications that need to update the input configuration.

Note

This function will stop any ongoing scan sequence.

ADC_InitSingle#

void ADC_InitSingle (ADC_TypeDef * adc, const ADC_InitSingle_TypeDef * init)

Initialize the single ADC sample conversion.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
const ADC_InitSingle_TypeDef *	[in]	init	A pointer to the ADC initialization structure.

See ADC_Start() for starting a single conversion.

When selecting an external reference, the gain and offset calibration must be set explicitly (CAL register). For other references, the calibration is updated with values defined during manufacturing.

Note

This function will stop any ongoing single conversion.

ADC_TimebaseCalc#

uint8_t ADC_TimebaseCalc (uint32_t hfperFreq)

Calculate a timebase value to get a timebase providing at least 1 us.

Parameters

Type	Direction	Argument Name	Description
uint32_t	[in]	hfperFreq	Frequency in Hz of the reference HFPER/HFPERC clock. Set to 0 to use currently defined HFPER/HFPERC clock setting.

Returns

A timebase value to use for ADC to achieve at least 1 us.

ADC_PrescaleCalc#

uint8_t ADC_PrescaleCalc (uint32_t adcFreq, uint32_t hfperFreq)

Calculate the prescaler value used to determine the ADC clock.

Parameters

Type	Direction	Argument Name	Description
uint32_t	[in]	adcFreq	ADC frequency wanted. The frequency will automatically be adjusted to a valid range according to the reference manual.
uint32_t	[in]	hfperFreq	Frequency in Hz of reference HFPER/HFPERC clock. Set to 0 to use currently defined HFPER/HFPERC clock setting.

The ADC clock is given by: (HFPERCLK or HFPERCCLK) / (prescale + 1).

Note

The return value is clamped to the maximum prescaler value that the hardware supports.

Returns

A prescaler value to use for ADC in order to achieve a clock value <= adcFreq.

ADC_IntClear#

void ADC_IntClear (ADC_TypeDef * adc, uint32_t flags)

Clear one or more pending ADC interrupts.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
uint32_t	[in]	flags	Pending ADC interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the ADC module (ADC_IF_nnn).

ADC_IntDisable#

void ADC_IntDisable (ADC_TypeDef * adc, uint32_t flags)

Disable one or more ADC interrupts.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
uint32_t	[in]	flags	ADC interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the ADC module (ADC_IF_nnn).

ADC_IntEnable#

void ADC_IntEnable (ADC_TypeDef * adc, uint32_t flags)

Enable one or more ADC interrupts.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
uint32_t	[in]	flags	ADC interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the ADC module (ADC_IF_nnn).

Note

Depending on use, a pending interrupt may already be set prior to enabling the interrupt. Consider using ADC_IntClear() prior to enabling if the pending interrupt should be ignored.

ADC_IntGet#

uint32_t ADC_IntGet (ADC_TypeDef * adc)

Get pending ADC interrupt flags.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.

Note

This function does not clear event bits.

Returns

ADC interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the ADC module (ADC_IF_nnn).

ADC_IntGetEnabled#

uint32_t ADC_IntGetEnabled (ADC_TypeDef * adc)

Get enabled and pending ADC interrupt flags.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.

Useful for handling more interrupt sources in the same interrupt handler.

Note

This function does not clear interrupt flags.

Returns

Pending and enabled ADC interrupt sources. The return value is the bitwise AND combination of
- the OR combination of enabled interrupt sources in ADCx_IEN_nnn register (ADCx_IEN_nnn) and
- the OR combination of valid interrupt flags of the ADC module (ADCx_IF_nnn).

ADC_IntSet#

void ADC_IntSet (ADC_TypeDef * adc, uint32_t flags)

Set one or more pending ADC interrupts from software.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
uint32_t	[in]	flags	ADC interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the ADC module (ADC_IF_nnn).

ADC_Start#

void ADC_Start (ADC_TypeDef * adc, ADC_Start_TypeDef cmd)

Start scan sequence and/or single conversion.

Parameters

Type	Direction	Argument Name	Description
ADC_TypeDef *	[in]	adc	A pointer to the ADC peripheral register block.
ADC_Start_TypeDef	[in]	cmd	A command indicating which type of sampling to start.