adc

Functions
void	ADC_init (uint16_t baseAddress, uint16_t sampleHoldSignalSourceSelect, uint8_t clockSourceSelect, uint16_t clockSourceDivider)
	Initializes the ADC Module. More...
void	ADC_enable (uint16_t baseAddress)
	Enables the ADC block. More...
void	ADC_disable (uint16_t baseAddress)
	Disables the ADC block. More...
void	ADC_setupSamplingTimer (uint16_t baseAddress, uint16_t clockCycleHoldCount, uint16_t multipleSamplesEnabled)
	Sets up and enables the Sampling Timer Pulse Mode. More...
void	ADC_disableSamplingTimer (uint16_t baseAddress)
	Disables Sampling Timer Pulse Mode. More...
void	ADC_configureMemory (uint16_t baseAddress, uint8_t inputSourceSelect, uint8_t positiveRefVoltageSourceSelect, uint8_t negativeRefVoltageSourceSelect)
	Configures the controls of the selected memory buffer. More...
void	ADC_enableInterrupt (uint16_t baseAddress, uint8_t interruptMask)
	Enables selected ADC interrupt sources. More...
void	ADC_disableInterrupt (uint16_t baseAddress, uint8_t interruptMask)
	Disables selected ADC interrupt sources. More...
void	ADC_clearInterrupt (uint16_t baseAddress, uint8_t interruptFlagMask)
	Clears ADC10B selected interrupt flags. More...
uint8_t	ADC_getInterruptStatus (uint16_t baseAddress, uint8_t interruptFlagMask)
	Returns the status of the selected memory interrupt flags. More...
void	ADC_startConversion (uint16_t baseAddress, uint8_t conversionSequenceModeSelect)
	Enables/Starts an Analog-to-Digital Conversion. More...
void	ADC_disableConversions (uint16_t baseAddress, bool preempt)
	Disables the ADC from converting any more signals. More...
int16_t	ADC_getResults (uint16_t baseAddress)
	Returns the raw contents of the specified memory buffer. More...
void	ADC_setResolution (uint16_t baseAddress, uint8_t resolutionSelect)
	Use to change the resolution of the converted data. More...
void	ADC_setSampleHoldSignalInversion (uint16_t baseAddress, uint16_t invertedSignal)
	Use to invert or un-invert the sample/hold signal. More...
void	ADC_setDataReadBackFormat (uint16_t baseAddress, uint16_t readBackFormat)
	Use to set the read-back format of the converted data. More...
void	ADC_setReferenceBufferSamplingRate (uint16_t baseAddress, uint16_t samplingRateSelect)
	Use to set the reference buffer's sampling rate. More...
void	ADC_setWindowComp (uint16_t baseAddress, uint16_t highThreshold, uint16_t lowThreshold)
	Sets the high and low threshold for the window comparator feature. More...
uint32_t	ADC_getMemoryAddressForDMA (uint16_t baseAddress)
	Returns the address of the memory buffer for the DMA module. More...
uint8_t	ADC_isBusy (uint16_t baseAddress)
	Returns the busy status of the ADC core. More...

Detailed Description

Function Documentation

void ADC_clearInterrupt	(	uint16_t	baseAddress,
		uint8_t	interruptFlagMask
	)

Clears ADC10B selected interrupt flags.

The selected ADC interrupt flags are cleared, so that it no longer asserts. The memory buffer interrupt flags are only cleared when the memory buffer is accessed.

Parameters

baseAddress

is the base address of the ADC module.

interruptFlagMask

is a bit mask of the interrupt flags to be cleared. Mask value is the logical OR of any of the following: ADC_OVERFLOW_INTERRUPT_FLAG - Interrupt flag for when a new conversion is about to overwrite the previous one ADC_TIMEOVERFLOW_INTERRUPT_FLAG - Interrupt flag for when a new conversion is starting before the previous one has finished ADC_ABOVETHRESHOLD_INTERRUPT_FLAG - Interrup flag for when the input signal has gone above the high threshold of the window comparator ADC_BELOWTHRESHOLD_INTERRUPT_FLAG - Interrupt flag for when the input signal has gone below the low threshold of the window comparator ADC_INSIDEWINDOW_INTERRUPT_FLAG - Interrupt flag for when the input signal is in between the high and low thresholds of the window comparator ADC_COMPLETED_INTERRUPT_FLAG - Interrupt flag for new conversion data in the memory buffer

Modified bits of ADCIFG register.

Returns

None

void ADC_configureMemory	(	uint16_t	baseAddress,
		uint8_t	inputSourceSelect,
		uint8_t	positiveRefVoltageSourceSelect,
		uint8_t	negativeRefVoltageSourceSelect
	)

Configures the controls of the selected memory buffer.

Maps an input signal conversion into the memory buffer, as well as the positive and negative reference voltages for each conversion being stored into the memory buffer. If the internal reference is used for the positive reference voltage, the internal REF module has to control the voltage level. Note that if a conversion has been started with the startConversion() function, then a call to disableConversions() is required before this function may be called.

Parameters

baseAddress	is the base address of the ADC module.
inputSourceSelect	is the input that will store the converted data into the specified memory buffer. Valid values are: ADC_INPUT_VEREF_N [Default] ADC_INPUT_VEREF_P ADC_INPUT_A2 ADC_INPUT_A3 ADC_INPUT_A4 ADC_INPUT_A5 ADC_INPUT_A6 ADC_INPUT_A7 ADC_INPUT_A8 - [Valid for FR4xx devices] ADC_INPUT_A9 - [Valid for FR4xx devices] ADC_INPUT_TEMPSENSOR ADC_INPUT_REFVOLTAGE ADC_INPUT_DVSS ADC_INPUT_DVCC Modified bits are ADCINCHx of ADCMCTL0 register.
positiveRefVoltageSourceSelect	is the reference voltage source to set as the upper limit for the conversion that is to be stored in the specified memory buffer. Valid values are: ADC_VREFPOS_AVCC [Default] ADC_VREFPOS_INT ADC_VREFPOS_EXT_BUF ADC_VREFPOS_EXT_NOBUF Modified bits are ADCSREF of ADCMCTL0 register.
negativeRefVoltageSourceSelect	is the reference voltage source to set as the lower limit for the conversion that is to be stored in the specified memory buffer. Valid values are: ADC_VREFNEG_AVSS [Default] ADC_VREFNEG_EXT Modified bits are ADCSREF of ADCMCTL0 register.

Returns

None

void ADC_disable

(

uint16_t

baseAddress

)

Disables the ADC block.

This will disable operation of the ADC block.

Parameters

baseAddress

is the base address of the ADC module.

Modified bits are ADCON of ADCCTL0 register.

Returns

None

void ADC_disableConversions	(	uint16_t	baseAddress,
		bool	preempt
	)

Disables the ADC from converting any more signals.

Disables the ADC from converting any more signals. If there is a conversion in progress, this function can stop it immediatly if the preempt parameter is set as ADC_PREEMPTCONVERSION, by changing the conversion mode to single- channel, single-conversion and disabling conversions. If the conversion mode is set as single-channel, single-conversion and this function is called without preemption, then the ADC core conversion status is polled until the conversion is complete before disabling conversions to prevent unpredictable data. If the ADC_startConversion() has been called, then this function has to be called to re-initialize the ADC, reconfigure a memory buffer control, enable/disable the sampling pulse mode, or change the internal reference voltage.

Parameters

baseAddress	is the base address of the ADC module.
preempt	specifies if the current conversion should be preemptly stopped before the end of the conversion Valid values are: ADC_COMPLETECONVERSION - Allows the ADC to end the current conversion before disabling conversions. ADC_PREEMPTCONVERSION - Stops the ADC10B immediatly, with unpredicatble results of the current conversion. Cannot be used with repeated conversion.

Modified bits of ADCCTL0 register and bits of ADCCTL1 register.

Returns

None

void ADC_disableInterrupt	(	uint16_t	baseAddress,
		uint8_t	interruptMask
	)

Disables selected ADC interrupt sources.

Disables the indicated ADC interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor.

Parameters

baseAddress

is the base address of the ADC module.

interruptMask

is the bit mask of the memory buffer interrupt sources to be disabled. Mask value is the logical OR of any of the following: ADC_OVERFLOW_INTERRUPT - Interrupts when a new conversion is about to overwrite the previous one ADC_TIMEOVERFLOW_INTERRUPT - Interrupts when a new conversion is starting before the previous one has finished ADC_ABOVETHRESHOLD_INTERRUPT - Interrups when the input signal has gone above the high threshold of the window comparator ADC_BELOWTHRESHOLD_INTERRUPT - Interrupts when the input signal has gone below the low threshold of the low window comparator ADC_INSIDEWINDOW_INTERRUPT - Interrupts when the input signal is in between the high and low thresholds of the window comparator ADC_COMPLETED_INTERRUPT - Interrupt for new conversion data in the memory buffer

Modified bits of ADCIE register.

Returns

None

void ADC_disableSamplingTimer

(

uint16_t

baseAddress

)

Disables Sampling Timer Pulse Mode.

Disables the Sampling Timer Pulse Mode. Note that if a conversion has been started with the startConversion() function, then a call to disableConversions() is required before this function may be called.

Parameters

baseAddress

is the base address of the ADC module.

Modified bits are ADCSHP of ADCCTL1 register.

Returns

None

void ADC_enable

(

uint16_t

baseAddress

)

Enables the ADC block.

This will enable operation of the ADC block.

Parameters

baseAddress

is the base address of the ADC module.

Modified bits are ADCON of ADCCTL0 register.

Returns

None

void ADC_enableInterrupt	(	uint16_t	baseAddress,
		uint8_t	interruptMask
	)

Enables selected ADC interrupt sources.

Enables the indicated ADC interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor. Does not clear interrupt flags.

Parameters

baseAddress

is the base address of the ADC module.

interruptMask

is the bit mask of the memory buffer interrupt sources to be enabled. Mask value is the logical OR of any of the following: ADC_OVERFLOW_INTERRUPT - Interrupts when a new conversion is about to overwrite the previous one ADC_TIMEOVERFLOW_INTERRUPT - Interrupts when a new conversion is starting before the previous one has finished ADC_ABOVETHRESHOLD_INTERRUPT - Interrups when the input signal has gone above the high threshold of the window comparator ADC_BELOWTHRESHOLD_INTERRUPT - Interrupts when the input signal has gone below the low threshold of the low window comparator ADC_INSIDEWINDOW_INTERRUPT - Interrupts when the input signal is in between the high and low thresholds of the window comparator ADC_COMPLETED_INTERRUPT - Interrupt for new conversion data in the memory buffer

Modified bits of ADCIE register.

Returns

None

uint8_t ADC_getInterruptStatus	(	uint16_t	baseAddress,
		uint8_t	interruptFlagMask
	)

Returns the status of the selected memory interrupt flags.

Returns the status of the selected interrupt flags.

Parameters

baseAddress

is the base address of the ADC module.

interruptFlagMask

is a bit mask of the interrupt flags status to be returned. Mask value is the logical OR of any of the following: ADC_OVERFLOW_INTERRUPT_FLAG - Interrupt flag for when a new conversion is about to overwrite the previous one ADC_TIMEOVERFLOW_INTERRUPT_FLAG - Interrupt flag for when a new conversion is starting before the previous one has finished ADC_ABOVETHRESHOLD_INTERRUPT_FLAG - Interrup flag for when the input signal has gone above the high threshold of the window comparator ADC_BELOWTHRESHOLD_INTERRUPT_FLAG - Interrupt flag for when the input signal has gone below the low threshold of the window comparator ADC_INSIDEWINDOW_INTERRUPT_FLAG - Interrupt flag for when the input signal is in between the high and low thresholds of the window comparator ADC_COMPLETED_INTERRUPT_FLAG - Interrupt flag for new conversion data in the memory buffer

Modified bits of ADC10IFG register.

Returns

The current interrupt flag status for the corresponding mask.

uint32_t ADC_getMemoryAddressForDMA

(

uint16_t

baseAddress

)

Returns the address of the memory buffer for the DMA module.

Parameters

baseAddress

is the base address of the ADC module.

Returns

the address of the memory buffer. This can be used in conjunction with the DMA to store the converted data directly to memory.

int16_t ADC_getResults

(

uint16_t

baseAddress

)

Returns the raw contents of the specified memory buffer.

Returns the raw contents of the specified memory buffer. The format of the content depends on the read-back format of the data: if the data is in signed 2's complement format then the contents in the memory buffer will be left-justified with the least-siginificant bits as 0's, whereas if the data is in unsigned format then the contents in the memory buffer will be right- justified with the most-significant bits as 0's.

Parameters

baseAddress

is the base address of the ADC module.

Returns

A Signed Integer of the contents of the specified memory buffer.

void ADC_init	(	uint16_t	baseAddress,
		uint16_t	sampleHoldSignalSourceSelect,
		uint8_t	clockSourceSelect,
		uint16_t	clockSourceDivider
	)

Initializes the ADC Module.

This function initializes the ADC module to allow for analog-to-digital conversions. Specifically this function sets up the sample-and-hold signal and clock sources for the ADC core to use for conversions. Upon successful completion of the initialization all of the ADC control registers will be reset, excluding the memory controls and reference module bits, the given parameters will be set, and the ADC core will be turned on (Note, that the ADC core only draws power during conversions and remains off when not converting).Note that sample/hold signal sources are device dependent. Note that if re-initializing the ADC after starting a conversion with the startConversion() function, the disableConversion() must be called BEFORE this function can be called.

Parameters

baseAddress	is the base address of the ADC module.
sampleHoldSignalSourceSelect	is the signal that will trigger a sample-and-hold for an input signal to be converted. This parameter is device specific and sources should be found in the device's datasheet. Valid values are: ADC_SAMPLEHOLDSOURCE_SC [Default] ADC_SAMPLEHOLDSOURCE_1 ADC_SAMPLEHOLDSOURCE_2 ADC_SAMPLEHOLDSOURCE_3 Modified bits are ADCSHSx of ADCCTL1 register.
clockSourceSelect	selects the clock that will be used by the ADC core and the sampling timer if a sampling pulse mode is enabled. Valid values are: ADC_CLOCKSOURCE_ADCOSC [Default] - MODOSC 5 MHz oscillator from the clock system ADC_CLOCKSOURCE_ACLK - The Auxilary Clock ADC_CLOCKSOURCE_SMCLK - The Sub-Master Clock Modified bits are ADCSSELx of ADCCTL1 register.
clockSourceDivider	selects the amount that the clock will be divided. Valid values are: ADC_CLOCKDIVIDER_1 [Default] ADC_CLOCKDIVIDER_2 ADC_CLOCKDIVIDER_3 ADC_CLOCKDIVIDER_4 ADC_CLOCKDIVIDER_5 ADC_CLOCKDIVIDER_6 ADC_CLOCKDIVIDER_7 ADC_CLOCKDIVIDER_8 ADC_CLOCKDIVIDER_12 ADC_CLOCKDIVIDER_16 ADC_CLOCKDIVIDER_20 ADC_CLOCKDIVIDER_24 ADC_CLOCKDIVIDER_28 ADC_CLOCKDIVIDER_32 ADC_CLOCKDIVIDER_64 ADC_CLOCKDIVIDER_128 ADC_CLOCKDIVIDER_192 ADC_CLOCKDIVIDER_256 ADC_CLOCKDIVIDER_320 ADC_CLOCKDIVIDER_384 ADC_CLOCKDIVIDER_448 ADC_CLOCKDIVIDER_512 Modified bits are ADCDIVx of ADCCTL1 register; bits ADCPDIVx of ADCCTL2 register.

Returns

None

uint8_t ADC_isBusy

(

uint16_t

baseAddress

)

Returns the busy status of the ADC core.

Returns the status of the ADC core if there is a conversion currently taking place.

Parameters

baseAddress

is the base address of the ADC module.

Returns

ADC_BUSY or ADC_NOTBUSY dependent if there is a conversion currently taking place. Return one of the following:

• ADC_NOTBUSY
• ADC_BUSY

void ADC_setDataReadBackFormat	(	uint16_t	baseAddress,
		uint16_t	readBackFormat
	)

Use to set the read-back format of the converted data.

Sets the format of the converted data: how it will be stored into the memory buffer, and how it should be read back. The format can be set as right-justified (default), which indicates that the number will be unsigned, or left-justified, which indicates that the number will be signed in 2's complement format. This change affects all memory buffers for subsequent conversions.

Parameters

baseAddress	is the base address of the ADC module.
readBackFormat	is the specified format to store the conversions in the memory buffer. Valid values are: ADC_UNSIGNED_BINARY [Default] ADC_SIGNED_2SCOMPLEMENT Modified bits are ADCDF of ADCCTL2 register.

Returns

None

void ADC_setReferenceBufferSamplingRate	(	uint16_t	baseAddress,
		uint16_t	samplingRateSelect
	)

Use to set the reference buffer's sampling rate.

Sets the reference buffer's sampling rate to the selected sampling rate. The default sampling rate is maximum of 200-ksps, and can be reduced to a maximum of 50-ksps to conserve power.

Parameters

baseAddress	is the base address of the ADC module.
samplingRateSelect	is the specified maximum sampling rate. Valid values are: ADC_MAXSAMPLINGRATE_200KSPS [Default] ADC_MAXSAMPLINGRATE_50KSPS Modified bits are ADCSR of ADCCTL2 register.

Modified bits of ADCCTL2 register.

Returns

None

void ADC_setResolution	(	uint16_t	baseAddress,
		uint8_t	resolutionSelect
	)

Use to change the resolution of the converted data.

This function can be used to change the resolution of the converted data from the default of 12-bits.

Parameters

baseAddress	is the base address of the ADC module.
resolutionSelect	determines the resolution of the converted data. Valid values are: ADC_RESOLUTION_8BIT ADC_RESOLUTION_10BIT [Default] Modified bits are ADCRES of ADCCTL2 register.

Returns

None

void ADC_setSampleHoldSignalInversion	(	uint16_t	baseAddress,
		uint16_t	invertedSignal
	)

Use to invert or un-invert the sample/hold signal.

This function can be used to invert or un-invert the sample/hold signal. Note that if a conversion has been started with the startConversion() function, then a call to disableConversions() is required before this function may be called.

Parameters

baseAddress	is the base address of the ADC module.
invertedSignal	set if the sample/hold signal should be inverted Valid values are: ADC_NONINVERTEDSIGNAL [Default] - a sample-and-hold of an input signal for conversion will be started on a rising edge of the sample/hold signal. ADC_INVERTEDSIGNAL - a sample-and-hold of an input signal for conversion will be started on a falling edge of the sample/hold signal. Modified bits are ADCISSH of ADCCTL1 register.

Returns

None

void ADC_setupSamplingTimer	(	uint16_t	baseAddress,
		uint16_t	clockCycleHoldCount,
		uint16_t	multipleSamplesEnabled
	)

Sets up and enables the Sampling Timer Pulse Mode.

This function sets up the sampling timer pulse mode which allows the sample/hold signal to trigger a sampling timer to sample-and-hold an input signal for a specified number of clock cycles without having to hold the sample/hold signal for the entire period of sampling. Note that if a conversion has been started with the startConversion() function, then a call to disableConversions() is required before this function may be called.

Parameters

baseAddress	is the base address of the ADC module.
clockCycleHoldCount	sets the amount of clock cycles to sample-and- hold for the memory buffer. Valid values are: ADC_CYCLEHOLD_4_CYCLES [Default] ADC_CYCLEHOLD_8_CYCLES ADC_CYCLEHOLD_16_CYCLES ADC_CYCLEHOLD_32_CYCLES ADC_CYCLEHOLD_64_CYCLES ADC_CYCLEHOLD_96_CYCLES ADC_CYCLEHOLD_128_CYCLES ADC_CYCLEHOLD_192_CYCLES ADC_CYCLEHOLD_256_CYCLES ADC_CYCLEHOLD_384_CYCLES ADC_CYCLEHOLD_512_CYCLES ADC_CYCLEHOLD_768_CYCLES ADC_CYCLEHOLD_1024_CYCLES Modified bits are ADCSHTx of ADCCTL0 register.
multipleSamplesEnabled	allows multiple conversions to start without a trigger signal from the sample/hold signal Valid values are: ADC_MULTIPLESAMPLESDISABLE - a timer trigger will be needed to start every ADC conversion. ADC_MULTIPLESAMPLESENABLE - during a sequenced and/or repeated conversion mode, after the first conversion, no sample/hold signal is necessary to start subsequent samples. Modified bits are ADCMSC of ADCCTL0 register.

Returns

None

void ADC_setWindowComp	(	uint16_t	baseAddress,
		uint16_t	highThreshold,
		uint16_t	lowThreshold
	)

Sets the high and low threshold for the window comparator feature.

Sets the high and low threshold for the window comparator feature. Use the ADCHIIE, ADCINIE, ADCLOIE interrupts to utilize this feature.

Parameters

baseAddress	is the base address of the ADC module.
highThreshold	is the upper bound that could trip an interrupt for the window comparator.
lowThreshold	is the lower bound that could trip on interrupt for the window comparator.

Modified bits of ADCLO register and bits of ADCHI register.

Returns

None

void ADC_startConversion	(	uint16_t	baseAddress,
		uint8_t	conversionSequenceModeSelect
	)

Enables/Starts an Analog-to-Digital Conversion.

This function enables/starts the conversion process of the ADC. If the sample/hold signal source chosen during initialization was ADCOSC, then the conversion is started immediately, otherwise the chosen sample/hold signal source starts the conversion by a rising edge of the signal. Keep in mind when selecting conversion modes, that for sequenced and/or repeated modes, to keep the sample/hold-and-convert process continuing without a trigger from the sample/hold signal source, the multiple samples must be enabled using the ADC_setupSamplingTimer() function. Also note that when a sequence conversion mode is selected, the first input channel is the one mapped to the memory buffer, the next input channel selected for conversion is one less than the input channel just converted (i.e. A1 comes after A2), until A0 is reached, and if in repeating mode, then the next input channel will again be the one mapped to the memory buffer. Note that after this function is called, the ADC_stopConversions() has to be called to re-initialize the ADC, reconfigure a memory buffer control, enable/disable the sampling timer, or to change the internal reference voltage.

Parameters

baseAddress

is the base address of the ADC module.

conversionSequenceModeSelect

determines the ADC operating mode. Valid values are: ADC_SINGLECHANNEL [Default] - one-time conversion of a single channel into a single memory buffer ADC_SEQOFCHANNELS - one time conversion of multiple channels into the specified starting memory buffer and each subsequent memory buffer up until the conversion is stored in a memory buffer dedicated as the end-of-sequence by the memory's control register ADC_REPEATED_SINGLECHANNEL - repeated conversions of one channel into a single memory buffer ADC_REPEATED_SEQOFCHANNELS - repeated conversions of multiple channels into the specified starting memory buffer and each subsequent memory buffer up until the conversion is stored in a memory buffer dedicated as the end-of-sequence by the memory's control register Modified bits are ADCCONSEQx of ADCCTL1 register.

Returns

None