Datasheet

19
[Not recommended for new designs - Use XMEGA A1U series] XMEGA A1 [DATASHEET]
8067O–AVR–06/2013
10. Event System
10.1 Features
 Inter-peripheral communication and signalling with minimum latency
 CPU and DMA independent operation
 8 Event Channels allows for up to 8 signals to be routed at the same time
 Events can be generated by
 Timer/Counters (TCxn)
 Real Time Counter (RTC)
 Analog to Digital Converters (ADCx)
 Analog Comparators (ACx)
 Ports (PORTx)
 System Clock (Clk
SYS
)
 Software (CPU)
 Events can be used by
 Timer/Counters (TCxn)
 Analog to Digital Converters (ADCx)
 Digital to Analog Converters (DACx)
 Ports (PORTx)
 DMA Controller (DMAC)
 IR Communication Module (IRCOM)
 The same event can be used by multiple peripherals for synchronized timing
 Advanced Features
 Manual Event Generation from software (CPU)
 Quadrature Decoding
 Digital Filtering
 Functions in Active and Idle mode
10.2 Overview
The Event System is a set of features for inter-peripheral communication. It enables the possibility for a change of state
in one peripheral to automatically trigger actions in one or more peripherals. These changes in a peripheral that will
trigger actions in other peripherals are configurable by software. It is a simple, but powerful system as it allows for
autonomous control of peripherals without any use of interrupts, CPU or DMA resources.
The indication of a change in a peripheral is referred to as an event, and is usually the same as the interrupt conditions
for that peripheral. Events are passed between peripherals using a dedicated routing network called the Event Routing
Network. Figure 10-1 on page 20 shows a basic block diagram of the Event System with the Event Routing Network and
the peripherals to which it is connected. This highly flexible system can be used for simple routing of signals, pin
functions or for sequencing of events.
The maximum latency is two CPU clock cycles from when an event is generated in one peripheral, until the actions are
triggered in one or more other peripherals.
The Event System is functional in both Active and Idle modes.