Microchip Technology megaAVR 0 Series Manual page 195

19.3.4 Events
The TCA is an event generator. The following events will generate a one-cycle strobe on the event
channel outputs:
• Timer overflow
• Timer underflow in Split mode
• Compare match channel 0
• Compare match channel 1
• Compare match channel 2
The peripheral can take the following actions on an input event:
• The counter counts positive edges of the event signal.
• The counter counts both positive and negative edges of the event signal.
• The counter counts prescaled clock cycles as long as the event signal is high.
• The counter counts prescaled clock cycles. The event signal controls the direction of counting. Up-
counting when the event signal is low and down-counting when the event signal is high.
The specific action is selected by writing to the Event Action bits (EVACT) in the Event Control register
(TCAn.EVCTRL). Events as input are enabled by writing a '1' to the Enable Count on Event Input bit
(CNTEI in TCAn.EVCTRL).
Event-controlled inputs are not used in Split mode.
19.3.5 Interrupts
Table 19-2. Available Interrupt Vectors and Sources in Normal Mode
Name Vector Description
OVF Overflow and Compare match
interrupt
CMP0 Compare channel 0 interrupt
CMP1 Compare channel 1 interrupt
CMP2 Compare channel 2 interrupt
Table 19-3. Available Interrupt Vectors and Sources in Split Mode
Name Vector Description
LUNF Low-byte Underflow interrupt Low-byte timer reaches BOTTOM.
HUNF High-byte Underflow interrupt High-byte timer reaches BOTTOM.
LCMP0 Compare channel 0 interrupt Match between the counter value and the low-byte of Compare
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2018 Microchip Technology Inc.
16-bit Timer/Counter Type A (TCA)
Conditions
The counter has reached its top value and wrapped to
zero.
Match between the counter value and the Compare 0
register.
Match between the counter value and the Compare 1
register.
Match between the counter value and the Compare 2
register.
Conditions
0 register.
Datasheet Preliminary
®
megaAVR 0-Series
DS40002015A-page 195