Datasheet

1079
32117D–AVR-01/12
AT32UC3C
35.6.6 Input Hysteresis
The user can select between no, low, and high hysteresis, by writing in the Hysteresis Selection
field in the CONF register (CONFx.HS). Adding hysteresis can avoid constant toggling of the
compare output if the input signals are very close to each other.
35.6.7 Startup Time
After enabling an Analog Comparator, the comparison is available after a start-up time defined in
the Start Up Time field in the Start Up Time register (SUT.SUT). During this time the AC output
is not available. The status bit SR.ACxRDY gives the information that the ACx has its output
available or not. In window mode the window mode output is available (SR.WFRDY is one) if
both comparator outputs are available (SR.ACARDY and SR.ACBRDY are both one).
When the start-up time is finished, the comparison can be disabled/enabled, by writing a one to
the corresponding AC Comparison Enable bit in the Enable register (EN.ACCPEN), without
waiting anymore.
35.6.8 Starting Signal Compare
In order to start a voltage comparison, the Analog Comparator must be configured with the pre-
ferred properties and the inputs to be used. After enabling the Analog Comparator, it should wait
for the startup time. When the startup time is over, the result of the comparison is available. It
can be read at all times in the SR register.