Atmel Xplained Pro Evaluation Kit ATSAMD20-XPRO ATSAMD20-XPRO Data Sheet

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Atmel | SMART SAM D20 [DATASHEET]

Atmel-42129K–SAM-D20_datasheet–06/2014

The DAC can generate a Data Buffer Empty event when DATABUF becomes empty and new data can be loaded to the 
buffer. The Data Buffer Empty event is enabled by writing a one to the Empty Event Output bit in the Event Control 
register (EVCTRL.EMPTYEO). A Data Buffer Empty interrupt request is generated if the Data Buffer Empty interrupt is 
enabled.

When the DAC is used at operating voltages lower than 2.5V, the voltage pump must be enabled. This enabling is done 
automatically, depending on operating voltage.

The voltage pump can be disabled by writing a one to the Voltage Pump Disable bit in the Control B register 
(CTRLB.VPD). This can be used to reduce power consumption when the operating voltage is above 2.5V.

The voltage pump uses the asynchronous GCLK_DAC clock, and requires that the clock frequency be at least four times 
higher than the sampling period.

As there is no automatic indication that a conversion is done, the sampling period must be greater than or equal to the 
specified conversion time.

Not applicable.

The DAC has the following interrupt sources:

z

Data Buffer Empty

z

Underrun 

z

Synchronization Ready 

Each interrupt source has an interrupt flag associated with it. The interrupt flag in the Interrupt Flag Status and Clear 
register (INTFLAG) is set when the interrupt condition occurs. Each interrupt can be individually enabled by writing a one 
to the corresponding bit in the Interrupt Enable Set register (INTENSET), and disabled by writing a one to the 
corresponding bit in the Interrupt Enable Clear register (INTENCLR). An interrupt request is generated when the interrupt 
flag is set and the corresponding interrupt is enabled. The interrupt request remains active until the interrupt flag is 
cleared, the interrupt is disabled or the DAC is reset. See the register description for details on how to clear interrupt 
flags. 

The DAC

 

has one common interrupt request line for all the interrupt sources. The user must read the INTFLAG register 

to determine which interrupt condition is present.

Note that interrupts must be globally enabled for interrupt requests to be generated. Refer to 

The DAC can generate the following output events:

z

Data Buffer Empty (EMPTY)

Writing a one to an Event Output bit in the Event Control register (EVCTRL.xxEO) enables the corresponding output 
event. Writing a zero to this bit disables the corresponding output event. Refer to 

for details on configuring the event system.

The DAC can take the following actions on an input event:

z

Start Conversion (START)

Writing a one to an Event Input bit in the Event Control register (EVCTRL.xxEI) enables the corresponding action on an 
input event. Writing a zero to this bit disables the corresponding action on input event. Note that if several events are