45
8068C–AVR–06/08
XMEGA A3
26.3
Input Selection
The Analog comparators have a very flexible input selection and the two comparators grouped
in a pair may be used to realize a window function. One pair of analog comparators is shown in
.
•
Input selection from pin
– Pin 0, 1, 2, 3, 4, 5, 6 selectable to positive input of analog comparator
– Pin 0, 1, 3, 5, 7 selectable to negative input of analog comparator
•
Internal signals available on positive analog comparator inputs
– Output from 12-bit DAC
•
Internal signals available on negative analog comparator inputs
– 64-level scaler of the VCC, available on negative analog comparator input
– Bandgap voltage reference
•
Output from 12-bit DAC
26.4
Window Function
The window function is realized by connecting the external inputs of the two analog comparators
in a pair as shown in
Figure 26-2.
Analog comparator window function
AC0
+
-
AC1
+
-
Input signal
Upper limit of window
Lower limit of window
Interrupt
sensitivity
control
Interrupts
Events