DAC
EMLIB

Detailed 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
struct DAC_InitChannel_TypeDef

Macros

#define DAC_INIT_DEFAULT
#define DAC_INITCHANNEL_DEFAULT

Enumerations

enum DAC_ConvMode_TypeDef {
dacConvModeContinuous = _DAC_CTRL_CONVMODE_CONTINUOUS,
dacConvModeSampleHold = _DAC_CTRL_CONVMODE_SAMPLEHOLD,
dacConvModeSampleOff = _DAC_CTRL_CONVMODE_SAMPLEOFF
}
enum DAC_Output_TypeDef {
dacOutputDisable = _DAC_CTRL_OUTMODE_DISABLE,
dacOutputPin = _DAC_CTRL_OUTMODE_PIN,
dacOutputADC = _DAC_CTRL_OUTMODE_ADC,
dacOutputPinADC = _DAC_CTRL_OUTMODE_PINADC
}
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
}
enum DAC_Ref_TypeDef {
dacRef1V25 = _DAC_CTRL_REFSEL_1V25,
dacRef2V5 = _DAC_CTRL_REFSEL_2V5,
dacRefVDD = _DAC_CTRL_REFSEL_VDD
}
enum DAC_Refresh_TypeDef {
dacRefresh8 = _DAC_CTRL_REFRSEL_8CYCLES,
dacRefresh16 = _DAC_CTRL_REFRSEL_16CYCLES,
dacRefresh32 = _DAC_CTRL_REFRSEL_32CYCLES,
dacRefresh64 = _DAC_CTRL_REFRSEL_64CYCLES
}

Functions

__STATIC_INLINE void DAC_Channel0OutputSet (DAC_TypeDef *dac, uint32_t value)
Set the output signal of DAC channel 0 to a given value.
__STATIC_INLINE void DAC_Channel1OutputSet (DAC_TypeDef *dac, uint32_t value)
Set the output signal of DAC channel 1 to a given value.
void DAC_ChannelOutputSet (DAC_TypeDef *dac, unsigned int channel, uint32_t value)
Set the output signal of a DAC channel to a given value.
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.
__STATIC_INLINE void DAC_IntClear (DAC_TypeDef *dac, uint32_t flags)
Clear one or more pending DAC interrupts.
__STATIC_INLINE void DAC_IntDisable (DAC_TypeDef *dac, uint32_t flags)
Disable one or more DAC interrupts.
__STATIC_INLINE void DAC_IntEnable (DAC_TypeDef *dac, uint32_t flags)
Enable one or more DAC interrupts.
__STATIC_INLINE uint32_t DAC_IntGet (DAC_TypeDef *dac)
Get pending DAC interrupt flags.
__STATIC_INLINE uint32_t DAC_IntGetEnabled (DAC_TypeDef *dac)
Get enabled and pending DAC interrupt flags. Useful for handling more interrupt sources in the same interrupt handler.
__STATIC_INLINE void DAC_IntSet (DAC_TypeDef *dac, uint32_t flags)
Set one or more pending DAC interrupts from SW.
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.

Macro Definition Documentation

#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.

Definition at line 169 of file em_dac.h .

#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.

Definition at line 209 of file em_dac.h .

Enumeration Type Documentation

enum DAC_ConvMode_TypeDef

Conversion mode.

Enumerator
dacConvModeContinuous

Continuous mode.

dacConvModeSampleHold

Sample/hold mode.

dacConvModeSampleOff

Sample/shut off mode.

Definition at line 67 of file em_dac.h .

enum 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.

Definition at line 74 of file em_dac.h .

enum 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.

Definition at line 82 of file em_dac.h .

enum DAC_Ref_TypeDef

Reference voltage for DAC.

Enumerator
dacRef1V25

Internal 1.25V bandgap reference.

dacRef2V5

Internal 2.5V bandgap reference.

dacRefVDD

VDD reference.

Definition at line 114 of file em_dac.h .

enum 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.

Definition at line 121 of file em_dac.h .

Function Documentation

__STATIC_INLINE void DAC_Channel0OutputSet ( DAC_TypeDef * dac,
uint32_t value
)

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] dac Pointer to DAC peripheral register block.
[in] value Value to write to the channel 0 output register CH0DATA.

Definition at line 244 of file em_dac.h .

Referenced by DAC_ChannelOutputSet() .

__STATIC_INLINE void DAC_Channel1OutputSet ( DAC_TypeDef * dac,
uint32_t value
)

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] dac Pointer to DAC peripheral register block.
[in] value Value to write to the channel 1 output register CH1DATA.

Definition at line 265 of file em_dac.h .

Referenced by 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] dac A pointer to the DAC peripheral register block.
[in] channel A channel number to set the output.
[in] value A value to write to the channel output register CHnDATA.

Definition at line 228 of file em_dac.c .

References DAC_Channel0OutputSet() , and DAC_Channel1OutputSet() .

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

Enable/disable the DAC channel.

Parameters
[in] dac A pointer to the DAC peripheral register block.
[in] ch A channel to enable/disable.
[in] enable true to enable DAC channel, false to disable.

Definition at line 84 of file em_dac.c .

References BUS_RegBitWrite() .

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] dac A pointer to the DAC peripheral register block.
[in] init A pointer to the DAC initialization structure.

Definition at line 117 of file em_dac.c .

References BUS_RegBitWrite() , DAC_Init_TypeDef::ch0ResetPre , DAC_Init_TypeDef::convMode , dacRef2V5 , dacRefVDD , DAC_Init_TypeDef::diff , DAC_Init_TypeDef::outEnablePRS , DAC_Init_TypeDef::outMode , DAC_Init_TypeDef::prescale , DAC_Init_TypeDef::reference , DAC_Init_TypeDef::refresh , and DAC_Init_TypeDef::sineEnable .

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

Initialize DAC channel.

Parameters
[in] dac A pointer to the DAC peripheral register block.
[in] init A pointer to the DAC initialization structure.
[in] ch A channel number to initialize.

Definition at line 181 of file em_dac.c .

References DAC_InitChannel_TypeDef::enable , DAC_InitChannel_TypeDef::prsEnable , DAC_InitChannel_TypeDef::prsSel , and DAC_InitChannel_TypeDef::refreshEnable .

__STATIC_INLINE void DAC_IntClear ( DAC_TypeDef * dac,
uint32_t flags
)

Clear one or more pending DAC interrupts.

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

Definition at line 283 of file em_dac.h .

__STATIC_INLINE void DAC_IntDisable ( DAC_TypeDef * dac,
uint32_t flags
)

Disable one or more DAC interrupts.

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

Definition at line 299 of file em_dac.h .

__STATIC_INLINE void DAC_IntEnable ( DAC_TypeDef * dac,
uint32_t flags
)

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] dac Pointer to DAC peripheral register block.
[in] flags DAC interrupt sources to enable. Use a bitwise logic OR combination of valid interrupt flags for the DAC module (DAC_IF_nnn).

Definition at line 320 of file em_dac.h .

__STATIC_INLINE uint32_t DAC_IntGet ( DAC_TypeDef * dac )

Get pending DAC interrupt flags.

Note
Event bits are not cleared by the use of this function.
Parameters
[in] dac Pointer 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).

Definition at line 339 of file em_dac.h .

__STATIC_INLINE uint32_t DAC_IntGetEnabled ( DAC_TypeDef * dac )

Get enabled and pending DAC interrupt flags. Useful for handling more interrupt sources in the same interrupt handler.

Parameters
[in] dac Pointer 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).

Definition at line 363 of file em_dac.h .

__STATIC_INLINE void DAC_IntSet ( DAC_TypeDef * dac,
uint32_t flags
)

Set one or more pending DAC interrupts from SW.

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

Definition at line 386 of file em_dac.h .

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] dacFreq DAC frequency wanted. The frequency will automatically be adjusted to be below the maximum allowed DAC clock.
[in] hfperFreq Frequency 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 .

Definition at line 266 of file em_dac.c .

References CMU_ClockFreqGet() , and cmuClock_HFPER .

void DAC_Reset ( DAC_TypeDef * dac )

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

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

Definition at line 305 of file em_dac.c .