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DAC peripheral driver interface. More...

Detailed Description

DAC peripheral driver interface.

Similar to the ADC driver interface (ADC), the DAC interface uses the concept of lines, corresponds to a tuple of a DAC device and a DAC output channel.

The DAC interface expects data to be served as a 16-bit unsigned integer, independent of the actual resolution of the hardware device. It is up to the DAC driver, to scale the given value to the maximal width that can be handled. The device driver should, on the other hand, implement the DAC in a way, that it will use the bit width, that comes closest to 16-bit.

This kind of 'auto-scaling' is quite sufficient for this interface, as standard DAC peripherals use a fixed conversion resolution internally anyway, so that any particular bit-width configuration on this driver level would not have much effect...

(Low-) Power Implications

The configured DAC peripherals are active (and consume power) from the point of initialization. When calling dac_poweroff(), the implementation should disable the given DAC line and put the DAC peripheral to sleep (e.g. through peripheral clock gating). When woken up again through dac_poweron(), the given DAC line should transparently continue it's previous operation.

The DAC driver implementation may need to block (and free) certain power modes in the driver's dac_init(), dac_poweron(), and the dac_poweroff() functions.


 DAC Direct Digital Synthesis


file  dac_dds_params.h
 Default configuration for the DAC DDS driver.
file  dac.h
 DAC peripheral driver interface definition.


 Default DAC undefined value.
#define DAC_LINE(x)   (x)
 Default DAC access macro.


typedef uint_fast8_t dac_t
 Define default DAC type identifier.


enum  { DAC_OK = 0 , DAC_NOLINE = -1 }
 Return codes used by the DAC driver interface. More...


int8_t dac_init (dac_t line)
 Initialize the given DAC line.
void dac_set (dac_t line, uint16_t value)
 Write a value onto DAC Device on a given Channel.
void dac_poweron (dac_t line)
 Enable the given DAC line.
void dac_poweroff (dac_t line)
 Disable the given DAC line.

Macro Definition Documentation


#define DAC_LINE (   x)    (x)

Default DAC access macro.

Definition at line 89 of file dac.h.



Default DAC undefined value.

Definition at line 82 of file dac.h.

Typedef Documentation

◆ dac_t

typedef uint_fast8_t dac_t

Define default DAC type identifier.

Definition at line 67 of file dac.h.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Return codes used by the DAC driver interface.

Definition at line 73 of file dac.h.

Function Documentation

◆ dac_init()

int8_t dac_init ( dac_t  line)

Initialize the given DAC line.

After initialization, the corresponding DAC line is active and its output is set to 0.

[in]lineDAC line to initialize
DAC_OK on success
DAC_NOLINE on invalid DAC line

◆ dac_poweroff()

void dac_poweroff ( dac_t  line)

Disable the given DAC line.

[in]lineDAC line to power off

◆ dac_poweron()

void dac_poweron ( dac_t  line)

Enable the given DAC line.

[in]lineDAC line to power on

◆ dac_set()

void dac_set ( dac_t  line,
uint16_t  value 

Write a value onto DAC Device on a given Channel.

The value is always given as 16-bit value and is internally scaled to the actual resolution that the DAC unit provides (e.g. 12-bit). So to get the maximum output voltage, this function has to be called with value set to 65535 (UINT16_MAX).

[in]lineDAC line to set
[in]valuevalue to set line to