DAC: 10-bit Digital To Analog Converter Driver

Overview

The MCUXpresso SDK provides a peripheral driver for the 10-bit digital to analog converter (DAC) module of MCUXpresso SDK devices.

Typical use case

Polling Configuration

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/dac

Interrupt Configuration

Refer to the driver examples codes located at <SDK_ROOT>/boards/<BOARD>/driver_examples/dac

Files
file	fsl_dac.h

Data Structures
struct	dac_config_t
	The configuration of DAC. More...

Enumerations
enum	dac_settling_time_t {   kDAC_SettlingTimeIs1us = 0U,   kDAC_SettlingTimeIs25us = 1U }
	The DAC settling time. More...

Functions
void	DAC_Init (DAC_Type *base, const dac_config_t *config)
	Initialize the DAC module. More...
void	DAC_Deinit (DAC_Type *base)
	De-Initialize the DAC module. More...
void	DAC_GetDefaultConfig (dac_config_t *config)
	Initializes the DAC user configuration structure. More...
void	DAC_EnableDoubleBuffering (DAC_Type *base, bool enable)
	Enable/Diable double-buffering feature. More...
void	DAC_SetBufferValue (DAC_Type *base, uint32_t value)
	Write DAC output value into CR register or pre-buffer. More...
void	DAC_SetCounterValue (DAC_Type *base, uint32_t value)
	Write DAC counter value into CNTVAL register. More...
static void	DAC_EnableDMA (DAC_Type *base, bool enable)
	Enable/Disable the DMA access. More...
static void	DAC_EnableCounter (DAC_Type *base, bool enable)
	Enable/Disable the counter operation. More...
static bool	DAC_GetDMAInterruptRequestFlag (DAC_Type *base)
	Get the status flag of DMA or interrupt request. More...

Driver version
#define	LPC_DAC_DRIVER_VERSION   (MAKE_VERSION(2, 0, 1))
	DAC driver version 2.0.1. More...

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Data Structure Documentation

struct dac_config_t

Data Fields
dac_settling_time_t	settlingTime
	The settling times are valid for a capacitance load on the DAC_OUT pin not exceeding 100 pF. More...

Field Documentation

dac_settling_time_t dac_config_t::settlingTime

A load impedance value greater than that value will cause settling time longer than the specified time. One or more graphs of load impedance vs. settling time will be included in the final data sheet.

Macro Definition Documentation

#define LPC_DAC_DRIVER_VERSION   (MAKE_VERSION(2, 0, 1))

Enumeration Type Documentation

enum dac_settling_time_t

Enumerator
kDAC_SettlingTimeIs1us	The settling time of the DAC is 1us max, and the maximum current is 700 mA. This allows a maximum update rate of 1 MHz.
kDAC_SettlingTimeIs25us	The settling time of the DAC is 2.5us and the maximum current is 350uA. This allows a maximum update rate of 400 kHz.

Function Documentation

void DAC_Init	(	DAC_Type *	base,
		const dac_config_t *	config
	)

Parameters

base	DAC peripheral base address.
config	The pointer to configuration structure. Please refer to "dac_config_t" structure.

void DAC_Deinit

(

DAC_Type *

base

)

Parameters

base	DAC peripheral base address.

void DAC_GetDefaultConfig

(

dac_config_t *

config

)

This function initializes the user configuration structure to a default value. The default values are as follows.

*   config->settlingTime = kDAC_SettlingTimeIs1us;
* 

Parameters

config

Pointer to the configuration structure. See "dac_config_t".

void DAC_EnableDoubleBuffering	(	DAC_Type *	base,
		bool	enable
	)

Notice: Disabling the double-buffering feature will disable counter opreation. If double-buffering feature is disabled, any writes to the CR address will go directly to the CR register. If double-buffering feature is enabled, any write to the CR register will only load the pre-buffer, which shares its register address with the CR register. The CR itself will be loaded from the pre-buffer whenever the counter reaches zero and the DMA request is set.

Parameters

base	DAC peripheral base address.
enable	Enable or disable the feature.

void DAC_SetBufferValue	(	DAC_Type *	base,
		uint32_t	value
	)

The DAC output voltage is VALUE*((VREFP)/1024).

Parameters

base	DAC peripheral base address.
value	Setting the value for items in the buffer. 10-bits are available.

void DAC_SetCounterValue	(	DAC_Type *	base,
		uint32_t	value
	)

   When the counter is enabled bit, the 16-bit counter will begin counting down, at the rate selected by PCLK,
   from the value programmed into the DACCNTVAL register. The counter is decremented Each time the counter

reaches zero, the counter will be reloaded by the value of DACCNTVAL and the DMA request bit INT_DMA_REQ will be set in hardware.

Parameters

base	DAC peripheral basic address.
value	Setting the value for items in the counter. 16-bits are available.

static void DAC_EnableDMA ( DAC_Type *  base, bool  enable  )

inlinestatic

Parameters

base	DAC peripheral base address.
enable	Enable or disable the feature.

static void DAC_EnableCounter ( DAC_Type *  base, bool  enable  )

inlinestatic

Parameters

base	DAC peripheral base address.
enable	Enable or disable the feature.

static bool DAC_GetDMAInterruptRequestFlag ( DAC_Type *  base )

inlinestatic

Parameters

base	DAC peripheral base address.

Returns

If return 'true', it means DMA request or interrupt occurs. If return 'false', it means DMA request or interrupt doesn't occur.