The ADC supports measure analog
signals and convert them to a digital representation with minimal CPU
intervention.
The ADC supports
fast 12-, 10-, and 8-bit analog-to-digital conversions. It implements a 12-bit SAR
core, sample and conversion mode control, and up to 4 independent
conversion-and-control buffers. The ADC allows up to 4 independent
analog-to-digital converter (ADC) samples to be converted and stored without any CPU
intervention.
ADC features
include:
- 1.68-Msps conversion rate at a
resolution of 12 bits
- Integrated hardware oversampling
for averaging up to 128 samples
- Full-scale ADC operating voltage
range
- Sample-and-hold with programmable
sampling periods controlled by software or timers
- Two sampling trigger sources:
software trigger and event trigger
- Software-selectable on-chip
reference voltage of 1.4V or 2.5V
- Configurable ADC reference
source: VDD, internal reference (VREF), or external
reference (VREF+ and VREF-)
- Up to 16
individually configurable analog input channels
- Internal conversion channels for
temperature sensing, supply monitoring, and analog signal chain (see the
device-specific data sheet for availability and channel mapping)
- Configurable ADC clock
source
- Single-channel,
repeat-single-channel, sequence (autoscan), and repeat-sequence (repeated
autoscan) conversion modes
- 4 conversion-result storage
registers (MEMRES0:3)
- Window comparator for low-power
monitoring of input signals from conversion-result registers
- DMA support with interrupt event
generation on completion of transfer
- Operates in RUN, SLEEP, and STOP
modes
- Can be triggered in any operating
mode except for SHUTDOWN
- Automatic power, reference, and
clock control for low-power operation
- Semi-automatic calibration of
CDAC trim values
Figure 14-1 shows the
functional block diagram of the ADC peripheral.