AT32UC3L064_1 ATMEL [ATMEL Corporation], AT32UC3L064_1 Datasheet - Page 609

• Manufacturer Part Number: AT32UC3L064_1
• Description: AVR32 32-bit Microcontroller
• Manufacturer: ATMEL [ATMEL Corporation]

26.5.4
26.5.5
26.5.6
26.6
26.6.1
26.6.2
32099A–AVR32–06/09
Functional Description
Interrupts
Peripheral Events
Debug Operation
Initializing the ADCIFB
Basic Operation
The ADCIFB interrupt request line is connected to the interrupt controller. Using the ADCIFB
interrupt request functionality requires the interrupt controller to be programmed first.
The ADCIFB peripheral events are connected via the Peripheral Event System. Refer to the
Peripheral Event System chapter for details
When an external debugger forces the CPU into debug mode, this module continues normal
operation. If this module is configured in a way that requires it to be periodically serviced by the
CPU through interrupt requests or similar, improper operation or data loss may result during
debugging.
The ADCIFB embeds a Successive Approximation Register (SAR) Analog-to-Digital Converter
(ADC). The ADC supports 8-bit or 10-bit resolutions, which can be extended to 11 or 12 bits by
the Enhanced Resolution Mode.
The conversion is performed on a full range between 0V and the reference voltage pin ADVREF.
Analog inputs between these voltages converts to digital values (codes) based on a linear con-
version. This linear conversion is described in the expression below where M is the number of
bits used to represent the analog value, Vin is the voltage of the analog value to convert, Vref is
the maximum voltage, and Code is the converted digital value.
The ADC Interface is enabled by writing a one to the Enable bit in the Control Register (CR.EN).
After the ADC Interface is enabled, the ADC timings needs to be configured by writing the cor-
rect values to the RES, PRESCAL, and STARTUP fields in the ADC Configuration Register
(ACR). See
I/O Controller must be configured correctly and the Reference Voltage (ADVREF) signal must be
connected. Refer to
To convert analog values to digital values the user must first initialize the ADCIFB as described
in
writing a one the corresponding bits in the Channel Enable Register (CHER). Enabling channel
N instructs the ADCIFB to convert the analog voltage applied to AD pin N at each conversion
sequence. Multiple channels can be enabled resulting in multiple AD pins being converted at
each conversion sequence.
To start converting data the user can either manually start a conversion sequence by writing a
one to the START bit in the Control Register (CR.START) or configure an automatic trigger to
initiate the conversions. The automatic trigger can be configured to trig on many different condi-
tions. Refer to
Section
26.6.1. When the ADCIFB is initialized the channels to convert must be enabled by
Section
Section 26.8.1
26.6.6, and
Section 26.5.1
for details.
Section 26.6.8
for details.
Code
=
for details. Before the ADCIFB can be used, the
2
------------------- -
M
V
⋅
ref
V
in
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