This section describes the programming interfaces of the Digital-to-Analog Converter(DAC) HAL driver. More...

Overview

This section describes the programming interfaces of the Digital-to-Analog Converter(DAC) HAL driver.

Terms and acronyms

The following provides descriptions to the terms commonly used in the DAC driver and how to use the various functions.

Terms	Details
DAC	DAC is a Digital-to-Analog Converter that converts digital data (usually binary) into an analog signal (current, voltage, or electric charge).

The general purpose DAC acts similar to a waveform generator. Resolution of the DAC is 10 bits. Features supported by this module are listed below:

Write the output data.
Before the DAC data output is enabled, it's written into the internal RAM dedicated to the DAC, the maximum memory capacity of 128 DAC data length, having 10 bits for each DAC data. User can write the DAC data to RAM by calling the function hal_dac_write_data().
Configure the output mode.
Data written into the internal RAM is transmitted as a waveform. Call function hal_dac_configure_output(), to set the output mode either on repeat mode by defining the first parameter "mode" as HAL_DAC_REPEAT_MODE. The parameter "start_address" and "end_address" together indicate the data range that is transmitted.
Start (Stop) data output.
Call hal_dac_start_output(), to transmit the DAC data in a user configured output mode (only repeat mode is supported right now). Call hal_dac_stop_output(), to stop the DAC output data transmission.

Note:
The "waveform" described in this document is actually discrete voltage values generated by ADC, and the frequency of these values is 1.08MHZ. Because when the output of ADC is captured by an oscilloscope, it seems continuous, so we describe the output as waveform for easy understanding.

Use DAC driver to output an analog waveform.
- Step1: Call hal_dac_init() to initialize the DAC module.
- Step2: Call hal_dac_write_data() to write data that will be outputed.
- Step3: Call hal_dac_configure_output() to configure the data range and output mode(only repeat mode is supported right now).
- Step4: Call hal_dac_start_output() to start the data conversion.
- Step5: Call hal_dac_stop_output() to stop the data conversion if needed.
- Step6: call hal_dac_deinit() to de-initialize the DAC module.
- NOTE: the waveform will be output from TP1101 if using LinkIt 2523 HDK. Please refer to LinkIt 2523 HDK user guide for more detail.
- Sample code:
  #define DATA_LEN 5
  uint32_t start_address = 0;
  uint32_t data[DATA_LEN] = {0x0010, 0x0011, 0x0012, 0x0013, 0x0014};
  hal_dac_init();//Initialize the DAC module.
  hal_dac_write_data(start_address, data, DATA_LEN);//Write DAC data to internal RAM.
  hal_dac_configure_output(HAL_DAC_REPEAT_MODE, start_address, start_address+DATA_LEN-1);//Configure the DAC output mode.
  hal_dac_start_output();//Start DAC conversion.
  hal_dac_stop_output();//Stop DAC if needed.
  hal_dac_deinit();//De-initialize the DAC module.

Functions
hal_dac_status_t	hal_dac_init (void)
	DAC initialization function. More...

hal_dac_status_t	hal_dac_deinit (void)
	DAC deinitialization function. More...

hal_dac_status_t	hal_dac_start_output (void)
	Start the DAC data conversion, data written into the internal RAM is transmitted as an analog waveform. More...

hal_dac_status_t	hal_dac_stop_output (void)
	Call this function to stop the DAC data conversion. More...

hal_dac_status_t	hal_dac_write_data (uint32_t start_address, const uint32_t *data, uint32_t length)
	Write data into the internal RAM, prepared to be converted as analog waveform. More...

hal_dac_status_t	hal_dac_configure_output (hal_dac_mode_t mode, uint32_t start_address, uint32_t end_address)
	This function configures the output mode of the DAC as well as the data range that will be outputted. More...

hal_dac_status_t hal_dac_configure_output	(	hal_dac_mode_t	mode,
		uint32_t	start_address,
		uint32_t	end_address
	)

This function configures the output mode of the DAC as well as the data range that will be outputted.

Parameters

[in]	mode	is the output mode of DAC, it is either repeat mode or no repeat mode, the parameter should be of type hal_dac_mode_t.
[in]	start_address	is the base address of the internal RAM that contains the data will be converted.
[in]	end_address	is the end address of data in the internal RAM.

Returns: HAL_DAC_STATUS_INVALID_PARAMETER, the start_address or end_address is invalid.
HAL_DAC_STATUS_ERROR, the mode is not HAL_DAC_REPEAT_MODE.
HAL_DAC_STATUS_OK, the DAC output is successfully configured.

Note: User should make sure that both the start_address and end_address are no more than 127.

hal_dac_status_t hal_dac_deinit ( void )

DAC deinitialization function.

This function resets the DAC peripheral registers to their default values.

Returns: HAL_DAC_STATUS_OK, the DAC is successfully deinitialized.
HAL_DAC_STATUS_ERROR, DAC clock disable failed.

hal_dac_status_t hal_dac_init ( void )

DAC initialization function.

Returns: HAL_DAC_STATUS_OK, the DAC is successfully initialized.
HAL_DAC_STATUS_ERROR_BUSY, the DAC is busy.
HAL_DAC_STATUS_ERROR, DAC clock enable failed.

hal_dac_status_t hal_dac_start_output ( void )

Start the DAC data conversion, data written into the internal RAM is transmitted as an analog waveform.

hal_dac_status_t hal_dac_stop_output ( void )

Call this function to stop the DAC data conversion.

hal_dac_status_t hal_dac_write_data	(	uint32_t	start_address,
		const uint32_t *	data,
		uint32_t	length
	)

Write data into the internal RAM, prepared to be converted as analog waveform.

Parameters

[in]	start_address	is the address for the data to be saved, should be 0~127.
[in]	data	is the base address of the data that will be written into the internal RAM.
[in]	length	is the length of the data that will be written.

Returns: HAL_DAC_STATUS_INVALID_PARAMETER, indicates that the combination of parameters start_address and length is out of range of the internal RAM, or the data is NULL.
HAL_DAC_STATUS_ERROR, writing data to the internal RAM failed.
HAL_DAC_STATUS_OK, writing data to the internal RAM is successful.