DAC - Digital to Analog Converter

Description

Digital to Analog Converter (DAC) Peripheral API.

This module contains functions to control the DAC peripheral of Silicon Labs 32-bit MCUs and SoCs. The DAC converts digital values to analog signals at up to 500 ksps with 12-bit accuracy. The DAC is designed for low-energy consumption and can also provide very good performance.

Data Structures

struct  DAC_Init_TypeDef
 DAC initialization structure, common for both channels.
 
struct  DAC_InitChannel_TypeDef
 DAC channel initialization structure.
 

Functions

void DAC_Enable (DAC_TypeDef *dac, unsigned int ch, bool enable)
 Enable/disable the DAC channel.
 
void DAC_Init (DAC_TypeDef *dac, const DAC_Init_TypeDef *init)
 Initialize DAC.
 
void DAC_InitChannel (DAC_TypeDef *dac, const DAC_InitChannel_TypeDef *init, unsigned int ch)
 Initialize DAC channel.
 
void DAC_ChannelOutputSet (DAC_TypeDef *dac, unsigned int channel, uint32_t value)
 Set the output signal of a DAC channel to a given value.
 
uint8_t DAC_PrescaleCalc (uint32_t dacFreq, uint32_t hfperFreq)
 Calculate prescaler value used to determine the DAC clock.
 
void DAC_Reset (DAC_TypeDef *dac)
 Reset DAC to the same state that it was in after a hardware reset.
 
void DAC_Channel0OutputSet (DAC_TypeDef *dac, uint32_t value)
 Set the output signal of DAC channel 0 to a given value.
 
void DAC_Channel1OutputSet (DAC_TypeDef *dac, uint32_t value)
 Set the output signal of DAC channel 1 to a given value.
 
void DAC_IntClear (DAC_TypeDef *dac, uint32_t flags)
 Clear one or more pending DAC interrupts.
 
void DAC_IntDisable (DAC_TypeDef *dac, uint32_t flags)
 Disable one or more DAC interrupts.
 
void DAC_IntEnable (DAC_TypeDef *dac, uint32_t flags)
 Enable one or more DAC interrupts.
 
uint32_t DAC_IntGet (DAC_TypeDef *dac)
 Get pending DAC interrupt flags.
 
uint32_t DAC_IntGetEnabled (DAC_TypeDef *dac)
 Get enabled and pending DAC interrupt flags.
 
void DAC_IntSet (DAC_TypeDef *dac, uint32_t flags)
 Set one or more pending DAC interrupts from SW.
 

Macros

#define DAC_INIT_DEFAULT
 Default configuration for DAC initialization structure.
 
#define DAC_INITCHANNEL_DEFAULT
 Default configuration for DAC channel initialization structure.
 

Enumerations

enum  DAC_ConvMode_TypeDef {
  dacConvModeContinuous = _DAC_CTRL_CONVMODE_CONTINUOUS,
  dacConvModeSampleHold = _DAC_CTRL_CONVMODE_SAMPLEHOLD,
  dacConvModeSampleOff = _DAC_CTRL_CONVMODE_SAMPLEOFF
}
 Conversion mode.
 
enum  DAC_Output_TypeDef {
  dacOutputDisable = _DAC_CTRL_OUTMODE_DISABLE,
  dacOutputPin = _DAC_CTRL_OUTMODE_PIN,
  dacOutputADC = _DAC_CTRL_OUTMODE_ADC,
  dacOutputPinADC = _DAC_CTRL_OUTMODE_PINADC
}
 Output mode.
 
enum  DAC_PRSSEL_TypeDef {
  dacPRSSELCh0 = _DAC_CH0CTRL_PRSSEL_PRSCH0,
  dacPRSSELCh1 = _DAC_CH0CTRL_PRSSEL_PRSCH1,
  dacPRSSELCh2 = _DAC_CH0CTRL_PRSSEL_PRSCH2,
  dacPRSSELCh3 = _DAC_CH0CTRL_PRSSEL_PRSCH3,
  dacPRSSELCh4 = _DAC_CH0CTRL_PRSSEL_PRSCH4,
  dacPRSSELCh5 = _DAC_CH0CTRL_PRSSEL_PRSCH5,
  dacPRSSELCh6 = _DAC_CH0CTRL_PRSSEL_PRSCH6,
  dacPRSSELCh7 = _DAC_CH0CTRL_PRSSEL_PRSCH7,
  dacPRSSELCh8 = _DAC_CH0CTRL_PRSSEL_PRSCH8,
  dacPRSSELCh9 = _DAC_CH0CTRL_PRSSEL_PRSCH9,
  dacPRSSELCh10 = _DAC_CH0CTRL_PRSSEL_PRSCH10,
  dacPRSSELCh11 = _DAC_CH0CTRL_PRSSEL_PRSCH11
}
 Peripheral Reflex System signal used to trigger single sample.
 
enum  DAC_Ref_TypeDef {
  dacRef1V25 = _DAC_CTRL_REFSEL_1V25,
  dacRef2V5 = _DAC_CTRL_REFSEL_2V5,
  dacRefVDD = _DAC_CTRL_REFSEL_VDD
}
 Reference voltage for DAC.
 
enum  DAC_Refresh_TypeDef {
  dacRefresh8 = _DAC_CTRL_REFRSEL_8CYCLES,
  dacRefresh16 = _DAC_CTRL_REFRSEL_16CYCLES,
  dacRefresh32 = _DAC_CTRL_REFRSEL_32CYCLES,
  dacRefresh64 = _DAC_CTRL_REFRSEL_64CYCLES
}
 Refresh interval.
 

Function Documentation

◆ DAC_Enable()

void DAC_Enable ( DAC_TypeDef *  dac,
unsigned int  ch,
bool  enable 
)

Enable/disable the DAC channel.

Parameters
[in]dacA pointer to the DAC peripheral register block.
[in]chA channel to enable/disable.
[in]enabletrue to enable DAC channel, false to disable.

◆ DAC_Init()

void DAC_Init ( DAC_TypeDef *  dac,
const DAC_Init_TypeDef init 
)

Initialize DAC.

Initializes common parts for both channels. In addition, channel control configuration must be done. See DAC_InitChannel().

Note
This function will disable both channels prior to configuration.
Parameters
[in]dacA pointer to the DAC peripheral register block.
[in]initA pointer to the DAC initialization structure.

◆ DAC_InitChannel()

void DAC_InitChannel ( DAC_TypeDef *  dac,
const DAC_InitChannel_TypeDef init,
unsigned int  ch 
)

Initialize DAC channel.

Parameters
[in]dacA pointer to the DAC peripheral register block.
[in]initA pointer to the DAC initialization structure.
[in]chA channel number to initialize.

◆ DAC_ChannelOutputSet()

void DAC_ChannelOutputSet ( DAC_TypeDef *  dac,
unsigned int  channel,
uint32_t  value 
)

Set the output signal of a DAC channel to a given value.

This function sets the output signal of a DAC channel by writing value to the corresponding CHnDATA register.

Parameters
[in]dacA pointer to the DAC peripheral register block.
[in]channelA channel number to set the output.
[in]valueA value to write to the channel output register CHnDATA.

◆ DAC_PrescaleCalc()

uint8_t DAC_PrescaleCalc ( uint32_t  dacFreq,
uint32_t  hfperFreq 
)

Calculate prescaler value used to determine the DAC clock.

The DAC clock is given by: HFPERCLK / (prescale ^ 2). If the requested DAC frequency is low and the maximum prescaler value can't adjust the actual DAC frequency lower than the requested DAC frequency, the maximum prescaler value is returned resulting in a higher DAC frequency than requested.

Parameters
[in]dacFreqDAC frequency wanted. The frequency will automatically be adjusted to be below the maximum allowed DAC clock.
[in]hfperFreqFrequency in Hz of the reference HFPER clock. Set to 0 to use the currently defined HFPER clock setting.
Returns
Prescaler value to use for DAC to achieve a clock value <= dacFreq.

◆ DAC_Reset()

void DAC_Reset ( DAC_TypeDef *  dac)

Reset DAC to the same state that it was in after a hardware reset.

Parameters
[in]dacA pointer to the ADC peripheral register block.

◆ DAC_Channel0OutputSet()

void DAC_Channel0OutputSet ( DAC_TypeDef *  dac,
uint32_t  value 
)
inline

Set the output signal of DAC channel 0 to a given value.

This function sets the output signal of DAC channel 0 by writing value to the CH0DATA register.

Parameters
[in]dacPointer to DAC peripheral register block.
[in]valueValue to write to the channel 0 output register CH0DATA.

◆ DAC_Channel1OutputSet()

void DAC_Channel1OutputSet ( DAC_TypeDef *  dac,
uint32_t  value 
)
inline

Set the output signal of DAC channel 1 to a given value.

Sets the output signal of DAC channel 1 by writing value to the CH1DATA register.

Parameters
[in]dacPointer to DAC peripheral register block.
[in]valueValue to write to the channel 1 output register CH1DATA.

◆ DAC_IntClear()

void DAC_IntClear ( DAC_TypeDef *  dac,
uint32_t  flags 
)
inline

Clear one or more pending DAC interrupts.

Parameters
[in]dacPointer to DAC peripheral register block.
[in]flagsPending DAC interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the DAC module (DAC_IF_nnn).

◆ DAC_IntDisable()

void DAC_IntDisable ( DAC_TypeDef *  dac,
uint32_t  flags 
)
inline

Disable one or more DAC interrupts.

Parameters
[in]dacPointer to DAC peripheral register block.
[in]flagsDAC interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the DAC module (DAC_IF_nnn).

◆ DAC_IntEnable()

void DAC_IntEnable ( DAC_TypeDef *  dac,
uint32_t  flags 
)
inline

Enable one or more DAC interrupts.

Note
Depending on the use, a pending interrupt may already be set prior to enabling the interrupt. To ignore a pending interrupt, consider using DAC_IntClear() prior to enabling the interrupt.
Parameters
[in]dacPointer to DAC peripheral register block.
[in]flagsDAC interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the DAC module (DAC_IF_nnn).

◆ DAC_IntGet()

uint32_t DAC_IntGet ( DAC_TypeDef *  dac)
inline

Get pending DAC interrupt flags.

Note
Event bits are not cleared by the use of this function.
Parameters
[in]dacPointer to DAC peripheral register block.
Returns
DAC interrupt sources pending. A bitwise logic OR combination of valid interrupt flags for the DAC module (DAC_IF_nnn).

◆ DAC_IntGetEnabled()

uint32_t DAC_IntGetEnabled ( DAC_TypeDef *  dac)
inline

Get enabled and pending DAC interrupt flags.

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

Parameters
[in]dacPointer to DAC peripheral register block.
Note
Interrupt flags are not cleared by the use of this function.
Returns
Pending and enabled DAC interrupt sources. Return value is the bitwise AND combination of
  • the OR combination of enabled interrupt sources in DACx_IEN_nnn register (DACx_IEN_nnn) and
  • the OR combination of valid interrupt flags of the DAC module (DACx_IF_nnn).

◆ DAC_IntSet()

void DAC_IntSet ( DAC_TypeDef *  dac,
uint32_t  flags 
)
inline

Set one or more pending DAC interrupts from SW.

Parameters
[in]dacPointer to DAC peripheral register block.
[in]flagsDAC interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the DAC module (DAC_IF_nnn).

Macro Definition Documentation

◆ DAC_INIT_DEFAULT

#define DAC_INIT_DEFAULT
Value:
{ \
dacRefresh8, /* Refresh every 8 prescaled cycles. */ \
dacRef1V25, /* 1.25V internal reference. */ \
dacOutputPin, /* Output to pin only. */ \
dacConvModeContinuous, /* Continuous mode. */ \
0, /* No prescaling. */ \
false, /* Do not enable low pass filter. */ \
false, /* Do not reset prescaler on ch0 start. */ \
false, /* DAC output enable always on. */ \
false, /* Disable sine mode. */ \
false /* Single ended mode. */ \
}

Default configuration for DAC initialization structure.

◆ DAC_INITCHANNEL_DEFAULT

#define DAC_INITCHANNEL_DEFAULT
Value:
{ \
false, /* Leave channel disabled when initialization done. */ \
false, /* Disable PRS triggering. */ \
false, /* Channel not refreshed automatically. */ \
dacPRSSELCh0 /* Select PRS ch0 (if PRS triggering enabled). */ \
}

Default configuration for DAC channel initialization structure.

Enumeration Type Documentation

◆ DAC_ConvMode_TypeDef

Conversion mode.

Enumerator
dacConvModeContinuous 

Continuous mode.

dacConvModeSampleHold 

Sample/hold mode.

dacConvModeSampleOff 

Sample/shut off mode.

◆ DAC_Output_TypeDef

Output mode.

Enumerator
dacOutputDisable 

Output to pin and ADC disabled.

dacOutputPin 

Output to pin only.

dacOutputADC 

Output to ADC only.

dacOutputPinADC 

Output to pin and ADC.

◆ DAC_PRSSEL_TypeDef

Peripheral Reflex System signal used to trigger single sample.

Enumerator
dacPRSSELCh0 

PRS channel 0.

dacPRSSELCh1 

PRS channel 1.

dacPRSSELCh2 

PRS channel 2.

dacPRSSELCh3 

PRS channel 3.

dacPRSSELCh4 

PRS channel 4.

dacPRSSELCh5 

PRS channel 5.

dacPRSSELCh6 

PRS channel 6.

dacPRSSELCh7 

PRS channel 7.

dacPRSSELCh8 

PRS channel 8.

dacPRSSELCh9 

PRS channel 9.

dacPRSSELCh10 

PRS channel 10.

dacPRSSELCh11 

PRS channel 11.

◆ DAC_Ref_TypeDef

Reference voltage for DAC.

Enumerator
dacRef1V25 

Internal 1.25V bandgap reference.

dacRef2V5 

Internal 2.5V bandgap reference.

dacRefVDD 

VDD reference.

◆ DAC_Refresh_TypeDef

Refresh interval.

Enumerator
dacRefresh8 

Refresh every 8 prescaled cycles.

dacRefresh16 

Refresh every 16 prescaled cycles.

dacRefresh32 

Refresh every 32 prescaled cycles.

dacRefresh64 

Refresh every 64 prescaled cycles.