VDAC

Detailed Description

Digital to Analog Voltage Converter (VDAC) Peripheral API.

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

The following steps are necessary for basic operation:

Clock enable:

CMU_ClockEnable(cmuClock_VDAC0, true);

Initialize the VDAC with default settings and modify selected fields:

VDAC_Init_TypeDef vdacInit          = VDAC_INIT_DEFAULT;
VDAC_InitChannel_TypeDef vdacChInit = VDAC_INITCHANNEL_DEFAULT;

// Set prescaler to get 1 MHz VDAC clock frequency.
vdacInit.prescaler = VDAC_PrescaleCalc(1000000, true, 0);
VDAC_Init(VDAC0, &vdacInit);

vdacChInit.enable = true;
VDAC_InitChannel(VDAC0, &vdacChInit, 0);

Perform a conversion:

VDAC_ChannelOutputSet(VDAC0, 0, 250);

Note

The output stage of a VDAC channel consist of an onchip operational amplifier in the OPAMP module. This opamp is highly configurable and to exploit the VDAC functionality fully, you might need to configure the opamp using the OPAMP API. By using the OPAMP API you will also load opamp calibration values. The default (reset) settings of the opamp will be sufficient for many applications.

Data Structures
struct	VDAC_Init_TypeDef
struct	VDAC_InitChannel_TypeDef

Macros
#define	VDAC_INIT_DEFAULT
#define	VDAC_INITCHANNEL_DEFAULT

Enumerations
enum	VDAC_PrsSel_TypeDef {   vdacPrsSelCh0 = _VDAC_CH0CTRL_PRSSEL_PRSCH0,   vdacPrsSelCh1 = _VDAC_CH0CTRL_PRSSEL_PRSCH1,   vdacPrsSelCh2 = _VDAC_CH0CTRL_PRSSEL_PRSCH2,   vdacPrsSelCh3 = _VDAC_CH0CTRL_PRSSEL_PRSCH3,   vdacPrsSelCh4 = _VDAC_CH0CTRL_PRSSEL_PRSCH4,   vdacPrsSelCh5 = _VDAC_CH0CTRL_PRSSEL_PRSCH5,   vdacPrsSelCh6 = _VDAC_CH0CTRL_PRSSEL_PRSCH6,   vdacPrsSelCh7 = _VDAC_CH0CTRL_PRSSEL_PRSCH7,   vdacPrsSelCh8 = _VDAC_CH0CTRL_PRSSEL_PRSCH8,   vdacPrsSelCh9 = _VDAC_CH0CTRL_PRSSEL_PRSCH9,   vdacPrsSelCh10 = _VDAC_CH0CTRL_PRSSEL_PRSCH10,   vdacPrsSelCh11 = _VDAC_CH0CTRL_PRSSEL_PRSCH11 }
enum	VDAC_Ref_TypeDef {   vdacRef1V25Ln = _VDAC_CTRL_REFSEL_1V25LN,   vdacRef2V5Ln = _VDAC_CTRL_REFSEL_2V5LN,   vdacRef1V25 = _VDAC_CTRL_REFSEL_1V25,   vdacRef2V5 = _VDAC_CTRL_REFSEL_2V5,   vdacRefAvdd = _VDAC_CTRL_REFSEL_VDD,   vdacRefExtPin = _VDAC_CTRL_REFSEL_EXT }
enum	VDAC_Refresh_TypeDef {   vdacRefresh8 = _VDAC_CTRL_REFRESHPERIOD_8CYCLES,   vdacRefresh16 = _VDAC_CTRL_REFRESHPERIOD_16CYCLES,   vdacRefresh32 = _VDAC_CTRL_REFRESHPERIOD_32CYCLES,   vdacRefresh64 = _VDAC_CTRL_REFRESHPERIOD_64CYCLES }
enum	VDAC_TrigMode_TypeDef {   vdacTrigModeSw = _VDAC_CH0CTRL_TRIGMODE_SW,   vdacTrigModePrs = _VDAC_CH0CTRL_TRIGMODE_PRS,   vdacTrigModeRefresh = _VDAC_CH0CTRL_TRIGMODE_REFRESH,   vdacTrigModeSwPrs = _VDAC_CH0CTRL_TRIGMODE_SWPRS,   vdacTrigModeSwRefresh = _VDAC_CH0CTRL_TRIGMODE_SWREFRESH,   vdacTrigModeLesense = _VDAC_CH0CTRL_TRIGMODE_LESENSE }

Functions
__STATIC_INLINE void	VDAC_Channel0OutputSet (VDAC_TypeDef *vdac, uint32_t value)
	Set the output signal of VDAC channel 0 to a given value. More...
__STATIC_INLINE void	VDAC_Channel1OutputSet (VDAC_TypeDef *vdac, uint32_t value)
	Set the output signal of VDAC channel 1 to a given value. More...
void	VDAC_ChannelOutputSet (VDAC_TypeDef *vdac, unsigned int channel, uint32_t value)
	Set the output signal of a VDAC channel to a given value. More...
void	VDAC_Enable (VDAC_TypeDef *vdac, unsigned int ch, bool enable)
	Enable/disable VDAC channel. More...
void	VDAC_Init (VDAC_TypeDef *vdac, const VDAC_Init_TypeDef *init)
	Initialize VDAC. More...
void	VDAC_InitChannel (VDAC_TypeDef *vdac, const VDAC_InitChannel_TypeDef *init, unsigned int ch)
	Initialize a VDAC channel. More...
__STATIC_INLINE void	VDAC_IntClear (VDAC_TypeDef *vdac, uint32_t flags)
	Clear one or more pending VDAC interrupts. More...
__STATIC_INLINE void	VDAC_IntDisable (VDAC_TypeDef *vdac, uint32_t flags)
	Disable one or more VDAC interrupts. More...
__STATIC_INLINE void	VDAC_IntEnable (VDAC_TypeDef *vdac, uint32_t flags)
	Enable one or more VDAC interrupts. More...
__STATIC_INLINE uint32_t	VDAC_IntGet (VDAC_TypeDef *vdac)
	Get pending VDAC interrupt flags. More...
__STATIC_INLINE uint32_t	VDAC_IntGetEnabled (VDAC_TypeDef *vdac)
	Get enabled and pending VDAC interrupt flags. Useful for handling more interrupt sources in the same interrupt handler. More...
__STATIC_INLINE void	VDAC_IntSet (VDAC_TypeDef *vdac, uint32_t flags)
	Set one or more pending VDAC interrupts from SW. More...
uint32_t	VDAC_PrescaleCalc (uint32_t vdacFreq, bool syncMode, uint32_t hfperFreq)
	Calculate prescaler value used to determine VDAC clock. More...
void	VDAC_Reset (VDAC_TypeDef *vdac)
	Reset VDAC to same state as after a HW reset. More...

Macro Definition Documentation

#define VDAC_INIT_DEFAULT

Value:

{                                                                         \
  true,                   /* Use main output path calibration values. */  \
  false,                  /* Use synchronous clock mode. */               \
  false,                  /* Turn off between sample off conversions.*/   \
  vdacRefresh8,           /* Refresh every 8th cycle. */                  \
  0,                      /* No prescaling. */                            \
  vdacRef1V25Ln,          /* 1.25V internal low noise reference. */       \
  false,                  /* Do not reset prescaler on CH 0 start. */     \
  false,                  /* VDAC output enable always on. */             \
  false,                  /* Disable sine mode. */                        \
  false                   /* Single ended mode. */                        \
}

Default config for VDAC init structure.

Definition at line 193 of file em_vdac.h.

#define VDAC_INITCHANNEL_DEFAULT

Value:

{                                                                             \
  false,              /* Leave channel disabled when init done. */            \
  vdacPrsSelCh0,      /* PRS CH 0 triggers conversion. */                     \
  false,              /* Treat PRS channel as a synchronous signal. */        \
  vdacTrigModeSw,     /* Conversion trigged by CH0DATA or COMBDATA write. */  \
  false,              /* Channel conversion set to continous. */              \
}

Default config for VDAC channel init structure.

Definition at line 230 of file em_vdac.h.

Enumeration Type Documentation

enum VDAC_PrsSel_TypeDef

Peripheral Reflex System signal used to trig VDAC channel conversion.

Enumerator
vdacPrsSelCh0	PRS ch 0 triggers conversion.
vdacPrsSelCh1	PRS ch 1 triggers conversion.
vdacPrsSelCh2	PRS ch 2 triggers conversion.
vdacPrsSelCh3	PRS ch 3 triggers conversion.
vdacPrsSelCh4	PRS ch 4 triggers conversion.
vdacPrsSelCh5	PRS ch 5 triggers conversion.
vdacPrsSelCh6	PRS ch 6 triggers conversion.
vdacPrsSelCh7	PRS ch 7 triggers conversion.
vdacPrsSelCh8	PRS ch 8 triggers conversion.
vdacPrsSelCh9	PRS ch 9 triggers conversion.
vdacPrsSelCh10	PRS ch 10 triggers conversion.
vdacPrsSelCh11	PRS ch 11 triggers conversion.

Definition at line 126 of file em_vdac.h.

enum VDAC_Ref_TypeDef

Reference voltage for VDAC.

Enumerator
vdacRef1V25Ln	Internal low noise 1.25 V bandgap reference.
vdacRef2V5Ln	Internal low noise 2.5 V bandgap reference.
vdacRef1V25	Internal 1.25 V bandgap reference.
vdacRef2V5	Internal 2.5 V bandgap reference.
vdacRefAvdd	AVDD reference.
vdacRefExtPin	External pin reference.

Definition at line 115 of file em_vdac.h.

enum VDAC_Refresh_TypeDef

Channel refresh period.

Enumerator
vdacRefresh8	Refresh every 8 clock cycles.
vdacRefresh16	Refresh every 16 clock cycles.
vdacRefresh32	Refresh every 32 clock cycles.
vdacRefresh64	Refresh every 64 clock cycles.

Definition at line 106 of file em_vdac.h.

enum VDAC_TrigMode_TypeDef

Channel conversion trigger mode.

Enumerator
vdacTrigModeSw	Channel is triggered by CHnDATA or COMBDATA write.
vdacTrigModePrs	Channel is triggered by PRS input.
vdacTrigModeRefresh	Channel is triggered by Refresh timer.
vdacTrigModeSwPrs	Channel is triggered by CHnDATA/COMBDATA write or PRS input.
vdacTrigModeSwRefresh	Channel is triggered by CHnDATA/COMBDATA write or Refresh timer.
vdacTrigModeLesense	Channel is triggered by LESENSE.

Definition at line 143 of file em_vdac.h.

Function Documentation

__STATIC_INLINE void VDAC_Channel0OutputSet	(	VDAC_TypeDef *	vdac,
		uint32_t	value
	)

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

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

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	value	Value to write to channel 0 output register CH0DATA.

Definition at line 266 of file em_vdac.h.

References _VDAC_CH0DATA_MASK, and VDAC_TypeDef::CH0DATA.

Referenced by VDAC_ChannelOutputSet().

__STATIC_INLINE void VDAC_Channel1OutputSet	(	VDAC_TypeDef *	vdac,
		uint32_t	value
	)

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

This function sets the output signal of VDAC channel 1 by writing value to the CH1DATA register.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	value	Value to write to channel 1 output register CH1DATA.

Definition at line 287 of file em_vdac.h.

References _VDAC_CH1DATA_MASK, and VDAC_TypeDef::CH1DATA.

Referenced by VDAC_ChannelOutputSet().

void VDAC_ChannelOutputSet	(	VDAC_TypeDef *	vdac,
		unsigned int	channel,
		uint32_t	value
	)

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

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

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	channel	Channel number to set output of.
[in]	value	Value to write to the channel output register CHnDATA.

Definition at line 316 of file em_vdac.c.

References VDAC_Channel0OutputSet(), and VDAC_Channel1OutputSet().

void VDAC_Enable	(	VDAC_TypeDef *	vdac,
		unsigned int	ch,
		bool	enable
	)

Enable/disable VDAC channel.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	ch	Channel to enable/disable.
[in]	enable	true to enable VDAC channel, false to disable.

Definition at line 81 of file em_vdac.c.

References VDAC_TypeDef::CMD, VDAC_TypeDef::STATUS, VDAC_CMD_CH0DIS, VDAC_CMD_CH0EN, VDAC_CMD_CH1DIS, VDAC_CMD_CH1EN, VDAC_STATUS_CH0ENS, and VDAC_STATUS_CH1ENS.

void VDAC_Init	(	VDAC_TypeDef *	vdac,
		const VDAC_Init_TypeDef *	init
	)

Initialize VDAC.

Initializes common parts for both channels. This function will also load calibration values from the Device Information (DI) page into the VDAC calibration register. To complete a VDAC setup, channel control configuration must also be done, please refer to VDAC_InitChannel().

Note

This function will disable both channels prior to configuration.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	init	Pointer to VDAC initialization structure.

Definition at line 132 of file em_vdac.c.

References _DEVINFO_VDAC0CH1CAL_GAINERRTRIMCH1A_MASK, _DEVINFO_VDAC0CH1CAL_GAINERRTRIMCH1A_SHIFT, _DEVINFO_VDAC0CH1CAL_GAINERRTRIMCH1B_MASK, _DEVINFO_VDAC0CH1CAL_GAINERRTRIMCH1B_SHIFT, _DEVINFO_VDAC0CH1CAL_OFFSETTRIM_MASK, _DEVINFO_VDAC0CH1CAL_OFFSETTRIM_SHIFT, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM1V25_MASK, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM1V25_SHIFT, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM1V25LN_MASK, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM1V25LN_SHIFT, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM2V5_MASK, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM2V5_SHIFT, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM2V5LN_MASK, _DEVINFO_VDAC0MAINCAL_GAINERRTRIM2V5LN_SHIFT, _DEVINFO_VDAC0MAINCAL_GAINERRTRIMVDDANAEXTPIN_MASK, _DEVINFO_VDAC0MAINCAL_GAINERRTRIMVDDANAEXTPIN_SHIFT, _VDAC_CAL_GAINERRTRIM_SHIFT, _VDAC_CAL_GAINERRTRIMCH1_SHIFT, _VDAC_CAL_OFFSETTRIM_SHIFT, _VDAC_CTRL_CH0PRESCRST_SHIFT, _VDAC_CTRL_DACCLKMODE_SHIFT, _VDAC_CTRL_DIFF_SHIFT, _VDAC_CTRL_OUTENPRS_SHIFT, _VDAC_CTRL_PRESC_MASK, _VDAC_CTRL_PRESC_SHIFT, _VDAC_CTRL_REFRESHPERIOD_SHIFT, _VDAC_CTRL_REFSEL_SHIFT, _VDAC_CTRL_SINEMODE_SHIFT, _VDAC_CTRL_WARMUPMODE_SHIFT, VDAC_Init_TypeDef::asyncClockMode, VDAC_TypeDef::CAL, VDAC_Init_TypeDef::ch0ResetPre, VDAC_TypeDef::CMD, VDAC_TypeDef::CTRL, DEVINFO, VDAC_Init_TypeDef::diff, VDAC_Init_TypeDef::mainCalibration, VDAC_Init_TypeDef::outEnablePRS, VDAC_Init_TypeDef::prescaler, VDAC_Init_TypeDef::reference, VDAC_Init_TypeDef::refresh, VDAC_Init_TypeDef::sineEnable, VDAC_TypeDef::STATUS, VDAC_CMD_CH0DIS, VDAC_CMD_CH1DIS, VDAC_STATUS_CH0ENS, VDAC_STATUS_CH1ENS, vdacRef1V25, vdacRef1V25Ln, vdacRef2V5, vdacRef2V5Ln, vdacRefAvdd, vdacRefExtPin, and VDAC_Init_TypeDef::warmupKeepOn.

void VDAC_InitChannel	(	VDAC_TypeDef *	vdac,
		const VDAC_InitChannel_TypeDef *	init,
		unsigned int	ch
	)

Initialize a VDAC channel.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	init	Pointer to VDAC channel initialization structure.
[in]	ch	Channel number to initialize.

Definition at line 240 of file em_vdac.c.

References _VDAC_CH0CTRL_CONVMODE_SHIFT, _VDAC_CH0CTRL_PRSASYNC_SHIFT, _VDAC_CH0CTRL_PRSSEL_SHIFT, _VDAC_CH0CTRL_TRIGMODE_SHIFT, VDAC_TypeDef::CH0CTRL, VDAC_TypeDef::CH1CTRL, VDAC_TypeDef::CMD, VDAC_InitChannel_TypeDef::enable, VDAC_InitChannel_TypeDef::prsAsync, VDAC_InitChannel_TypeDef::prsSel, VDAC_InitChannel_TypeDef::sampleOffMode, VDAC_TypeDef::STATUS, VDAC_InitChannel_TypeDef::trigMode, VDAC_CMD_CH0DIS, VDAC_CMD_CH0EN, VDAC_CMD_CH1DIS, VDAC_CMD_CH1EN, VDAC_STATUS_CH0ENS, and VDAC_STATUS_CH1ENS.

__STATIC_INLINE void VDAC_IntClear	(	VDAC_TypeDef *	vdac,
		uint32_t	flags
	)

Clear one or more pending VDAC interrupts.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	flags	Pending VDAC interrupt source to clear. Use a bitwise logic OR combination of valid interrupt flags for the VDAC module (VDAC_IF_nnn).

Definition at line 305 of file em_vdac.h.

References VDAC_TypeDef::IFC.

__STATIC_INLINE void VDAC_IntDisable	(	VDAC_TypeDef *	vdac,
		uint32_t	flags
	)

Disable one or more VDAC interrupts.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	flags	VDAC interrupt sources to disable. Use a bitwise logic OR combination of valid interrupt flags for the VDAC module (VDAC_IF_nnn).

Definition at line 321 of file em_vdac.h.

References VDAC_TypeDef::IEN.

__STATIC_INLINE void VDAC_IntEnable	(	VDAC_TypeDef *	vdac,
		uint32_t	flags
	)

Enable one or more VDAC interrupts.

Note

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

Parameters

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

Definition at line 342 of file em_vdac.h.

References VDAC_TypeDef::IEN.

__STATIC_INLINE uint32_t VDAC_IntGet

(

VDAC_TypeDef *

vdac

)

Get pending VDAC interrupt flags.

Note

The event bits are not cleared by the use of this function.

Parameters

[in]

vdac

Pointer to VDAC peripheral register block.

Returns

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

Definition at line 361 of file em_vdac.h.

References VDAC_TypeDef::IF.

__STATIC_INLINE uint32_t VDAC_IntGetEnabled

(

VDAC_TypeDef *

vdac

)

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

Parameters

[in]

vdac

Pointer to VDAC peripheral register block.

Note

Interrupt flags are not cleared by the use of this function.

Returns

Pending and enabled VDAC interrupt sources. The return value is the bitwise AND combination of

• the OR combination of enabled interrupt sources in VDACx_IEN_nnn register (VDACx_IEN_nnn) and
• the OR combination of valid interrupt flags of the VDAC module (VDACx_IF_nnn).

Definition at line 385 of file em_vdac.h.

References VDAC_TypeDef::IEN, and VDAC_TypeDef::IF.

__STATIC_INLINE void VDAC_IntSet	(	VDAC_TypeDef *	vdac,
		uint32_t	flags
	)

Set one or more pending VDAC interrupts from SW.

Parameters

[in]	vdac	Pointer to VDAC peripheral register block.
[in]	flags	VDAC interrupt sources to set to pending. Use a bitwise logic OR combination of valid interrupt flags for the VDAC module (VDAC_IF_nnn).

Definition at line 404 of file em_vdac.h.

References VDAC_TypeDef::IFS.

uint32_t VDAC_PrescaleCalc	(	uint32_t	vdacFreq,
		bool	syncMode,
		uint32_t	hfperFreq
	)

Calculate prescaler value used to determine VDAC clock.

The VDAC clock is given by input clock divided by prescaler+1.

VDAC_CLK = IN_CLK / (prescale + 1)

Maximum VDAC clock is 1 MHz. Input clock is HFPERCLK when VDAC synchronous mode is selected, or an internal oscillator of 10 MHz +/- 20% when asynchronous mode is selected.

Note

If the requested VDAC frequency is low and the max prescaler value can not adjust the actual VDAC frequency lower than requested, the max prescaler value is returned, resulting in a higher VDAC frequency than requested.

Parameters

[in]	vdacFreq	VDAC frequency target. The frequency will automatically be adjusted to be below max allowed VDAC clock.
[in]	syncMode	Set to true if you intend to use VDAC in synchronous mode.
[in]	hfperFreq	Frequency in Hz of HFPERCLK oscillator. Set to 0 to use currently defined HFPERCLK clock setting. This parameter is only used when syncMode is set to true.

Returns

Prescaler value to use for VDAC in order to achieve a clock value less than or equal to vdacFreq.

Definition at line 366 of file em_vdac.c.

References _VDAC_CTRL_PRESC_MASK, _VDAC_CTRL_PRESC_SHIFT, CMU_ClockFreqGet(), and cmuClock_HFPER.

void VDAC_Reset

(

VDAC_TypeDef *

vdac

)

Reset VDAC to same state as after a HW reset.

Parameters

[in]

vdac

Pointer to VDAC peripheral register block.

Definition at line 420 of file em_vdac.c.

References _VDAC_CAL_RESETVALUE, _VDAC_CH0CTRL_RESETVALUE, _VDAC_CH0DATA_RESETVALUE, _VDAC_CH1CTRL_RESETVALUE, _VDAC_CH1DATA_RESETVALUE, _VDAC_CTRL_RESETVALUE, _VDAC_IEN_RESETVALUE, _VDAC_IFC_MASK, VDAC_TypeDef::CAL, VDAC_TypeDef::CH0CTRL, VDAC_TypeDef::CH0DATA, VDAC_TypeDef::CH1CTRL, VDAC_TypeDef::CH1DATA, VDAC_TypeDef::CMD, VDAC_TypeDef::CTRL, VDAC_TypeDef::IEN, VDAC_TypeDef::IFC, VDAC_TypeDef::STATUS, VDAC_CMD_CH0DIS, VDAC_CMD_CH1DIS, VDAC_STATUS_CH0ENS, and VDAC_STATUS_CH1ENS.