Functions
fsp_err_t	R_DAC_Open (dac_ctrl_t p_api_ctrl, dac_cfg_t const const p_cfg)

fsp_err_t	R_DAC_Write (dac_ctrl_t *p_api_ctrl, uint16_t value)

fsp_err_t	R_DAC_Start (dac_ctrl_t *p_api_ctrl)

fsp_err_t	R_DAC_Stop (dac_ctrl_t *p_api_ctrl)

fsp_err_t	R_DAC_Close (dac_ctrl_t *p_api_ctrl)

Detailed Description

Driver for the DAC12 peripheral on RA MCUs. This module implements the DAC Interface.

Overview

Features

The DAC module outputs one of 4096 voltage levels between the positive and negative reference voltages.

Supports setting left-justified or right-justified 12-bit value format for the 16-bit input data registers
Supports output amplifiers on selected MCUs
Supports charge pump on selected MCUs
Supports synchronization with the Analog-to-Digital Converter (ADC) module

Configuration

Note

For MCUs supporting more than one channel, the following configuration options are shared by all the DAC channels:

Synchronize with ADC
Data Format
Charge Pump

Build Time Configurations for r_dac

The following build time configurations are defined in fsp_cfg/r_dac_cfg.h:

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	If selected code for parameter checking is included in the build.

Configurations for Analog > DAC (r_dac)

This module can be added to the Stacks tab via New Stack > Analog > DAC (r_dac). Non-secure callable guard functions can be generated for this module by right clicking the module in the RA Configuration tool and checking the "Non-secure Callable" box.

Configuration	Options	Default	Description
Name	Name must be a valid C symbol	g_dac0	Module name.
Channel	Value must be an integer greater than or equal to 0	0	Specify the hardware channel.
Synchronize with ADC	MCU Specific Options		Enable DA/AD synchronization.
Data Format	Right Justified Left Justified	Right Justified	Specify the DAC data format.
Output Amplifier	MCU Specific Options		Enable the DAC output amplifier.
Charge Pump (Requires MOCO active)	MCU Specific Options		Enable the DAC charge pump.
Internal Output	MCU Specific Options		Enable DAC output to internal modules.
ELC Trigger Source	MCU Specific Options		ELC event source that will trigger the DAC to start a conversion.
Reference Voltage	MCU Specific Options		Select the DAC reference voltage.

Clock Configuration

The DAC peripheral module uses PCLKB as its clock source.

Pin Configuration

The DAn pins are used as analog outputs. Each DAC channel has one output pin.

The AVCC0 and AVSS0 pins are power and ground supply pins for the DAC and ADC.

The VREFH and VREFL pins are top and ground voltage reference pins for the DAC and ADC.

Usage Notes

Charge Pump

The charge pump must be enabled when using DAC pin output while operating at AV_CC < 2.7V.

Note: The MOCO must be running to use the charge pump.; If the DAC output is to be routed to an internal signal, do not enable the charge pump.

Output to Internal Modules

The DAC output can be used as an analog input to other peripherals on the MCU (eg. ACMPHS, ADC) without outputting the voltage to an external pin.

On some MCUs this functionality must be enabled during configuration using dac_extended_cfg_t::internal_output_enabled. When internal output is enabled, the DAC output will be routed to internal modules. If the DAC output amplifier is enabled or when internal output is disabled, the output will be routed to the DAC output pin (DAn).

Synchronization with ADC

When ADC synchronization is enabled and an ADC conversion is in progress, if a DAC conversion is started it will automatically be delayed until after the ADC conversion is complete.

Limitations

For MCUs supporting ADC unit 1:
- Once synchronization between DAC and ADC unit 1 is turned on during R_DAC_Open synchronization cannot be turned off by the driver. In order to desynchronize DAC with ADC unit 1, manually clear DAADSCR.DAADST to 0 when the ADCSR.ADST bit is 0 and ADC unit 1 is halted.
- The DAC module can only be synchronized with ADC unit 1.
- For MCUs having more than 1 DAC channel, both channels are synchronized with ADC unit 1 if synchronization is enabled.

Examples

Basic Example

This is a basic example of minimal use of the R_DAC in an application. This example shows how this driver can be used for basic Digital to Analog Conversion operations.

void basic_example (void)
{
    fsp_err_t err;
    uint16_t  value;
    /* Pin configuration: Output enable DA0 as Analog. */
    /* Initialize the DAC channel */
    err = R_DAC_Open(&g_dac_ctrl, &g_dac_cfg);
    /* Handle any errors. This function should be defined by the user. */
    assert(FSP_SUCCESS == err);
    value = (uint16_t) DAC_EXAMPLE_VALUE_ABC;
    err = R_DAC_Write(&g_dac_ctrl, value);
    assert(FSP_SUCCESS == err);
    err = R_DAC_Start(&g_dac_ctrl);
    assert(FSP_SUCCESS == err);
}

Data Structures
struct	dac_instance_ctrl_t

struct	dac_extended_cfg_t

Enumerations
enum	dac_ref_volt_sel_t

Data Structure Documentation

◆ dac_instance_ctrl_t

struct dac_instance_ctrl_t

DAC instance control block.

◆ dac_extended_cfg_t

struct dac_extended_cfg_t

DAC extended configuration

Data Fields
bool	enable_charge_pump	Enable DAC charge pump available on selected MCUs.
bool	output_amplifier_enabled	Output amplifier enable available on selected MCUs.
bool	internal_output_enabled	Internal output enable available on selected MCUs.
dac_data_format_t	data_format	Data format.
dac_ref_volt_sel_t	ref_volt_sel	Reference voltage selection.

Enumeration Type Documentation

◆ dac_ref_volt_sel_t

enum dac_ref_volt_sel_t

DAC Reference voltage selection.

Enumerator
DAC_VREF_NONE	No reference voltage selected.
DAC_VREF_AVCC0_AVSS0	Select AVCC0/AVSS0.
DAC_VREF_IVREF_AVSS0	Select Internal reference voltage/AVSS0.
DAC_VREF_VREFH_VREFL	Select VREFH/VREFL.

Function Documentation

◆ R_DAC_Open()

fsp_err_t R_DAC_Open	(	dac_ctrl_t *	p_api_ctrl,
		dac_cfg_t const *const	p_cfg
	)

Perform required initialization described in hardware manual. Implements dac_api_t::open. Configures a single DAC channel, starts the channel, and provides a handle for use with the DAC API Write and Close functions. Must be called once prior to calling any other DAC API functions. After a channel is opened, Open should not be called again for the same channel without calling Close first.

Return values

FSP_SUCCESS	The channel was successfully opened.
FSP_ERR_ASSERTION	Parameter check failure due to one or more reasons below: One or both of the following parameters may be NULL: p_api_ctrl or p_cfg data_format value in p_cfg is out of range. Extended configuration structure is set to NULL for MCU supporting charge pump.
FSP_ERR_IP_CHANNEL_NOT_PRESENT	Channel ID requested in p_cfg may not available on the devices.
FSP_ERR_ALREADY_OPEN	The control structure is already opened.

◆ R_DAC_Write()

fsp_err_t R_DAC_Write	(	dac_ctrl_t *	p_api_ctrl,
		uint16_t	value
	)

Write data to the D/A converter and enable the output if it has not been enabled.

Return values

FSP_SUCCESS	Data is successfully written to the D/A Converter.
FSP_ERR_ASSERTION	p_api_ctrl is NULL.
FSP_ERR_NOT_OPEN	Channel associated with p_ctrl has not been opened.

◆ R_DAC_Start()

fsp_err_t R_DAC_Start ( dac_ctrl_t * p_api_ctrl )

Start the D/A conversion output if it has not been started.

Return values

FSP_SUCCESS	The channel is started successfully.
FSP_ERR_ASSERTION	p_api_ctrl is NULL.
FSP_ERR_IN_USE	Attempt to re-start a channel.
FSP_ERR_NOT_OPEN	Channel associated with p_ctrl has not been opened.

◆ R_DAC_Stop()

fsp_err_t R_DAC_Stop ( dac_ctrl_t * p_api_ctrl )

Stop the D/A conversion and disable the output signal.

Return values

FSP_SUCCESS	The control is successfully stopped.
FSP_ERR_ASSERTION	p_api_ctrl is NULL.
FSP_ERR_NOT_OPEN	Channel associated with p_ctrl has not been opened.

◆ R_DAC_Close()

fsp_err_t R_DAC_Close ( dac_ctrl_t * p_api_ctrl )

Stop the D/A conversion, stop output, and close the DAC channel.

Return values

FSP_SUCCESS	The channel is successfully closed.
FSP_ERR_ASSERTION	p_api_ctrl is NULL.
FSP_ERR_NOT_OPEN	Channel associated with p_ctrl has not been opened.

Functions

Detailed Description

Overview

Features

Configuration

Build Time Configurations for r_dac

Configurations for Analog > DAC (r_dac)

Clock Configuration

Pin Configuration

Usage Notes

Charge Pump

Output to Internal Modules

Synchronization with ADC

Limitations

Examples

Basic Example

Data Structures

Enumerations

Data Structure Documentation

◆ dac_instance_ctrl_t

◆ dac_extended_cfg_t

Enumeration Type Documentation

◆ dac_ref_volt_sel_t

Function Documentation

◆ R_DAC_Open()

◆ R_DAC_Write()

◆ R_DAC_Start()

◆ R_DAC_Stop()

◆ R_DAC_Close()