ATAVRDISPLAYX Atmel, ATAVRDISPLAYX Datasheet - Page 69

• Manufacturer Part Number: ATAVRDISPLAYX
• Description: KIT EVAL XMEGA DISPLAY
• Manufacturer: Atmel

Specifications of ATAVRDISPLAYX

• Main Purpose: *
• Embedded: *
• Utilized Ic / Part: *
• Primary Attributes: *
• Secondary Attributes: *
• Silicon Manufacturer: Atmel
• Silicon Family Name: ATxmega
• Kit Contents: Board
• Features: Temperature Sensor, Mono Speaker Via Audio Amplifier
• Svhc: No SVHC (15-Dec-2010)
• Core Architecture: AVR
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6.5
6.6
6.7
6.7.1
8077H–AVR–12/09
Event Timing
Filtering
Quadrature Decoder
Quadrature Operation
An event normally lasts for one peripheral clock cycle, but some event sources, such as low
level on an I/O pin, will generate events continuously. Details on this are described in the
datasheet for each peripheral, but unless stated, an event lasts for one peripheral clock cycle
only.
It takes maximum two clock cycles from an event is generated until the event actions in other
peripherals is triggered. It takes one clock cycle from the event happens until it is registered by
the event routing network on the first positive clock edge. It takes an additional clock cycle to
route the event through the event channel to the event user.
Each event channel includes a digital filter. When this is enabled for an event channel, an event
must be sampled with the same value for configurable number of system clock cycles before it is
accepted. This is primarily intended for pin change events.
The Event System includes three Quadrature Decoders (QDECs). This enables the Event Sys-
tem to decode quadrature input on I/O pins, and send data events that a Timer/Counter can
decode to trigger the appropriate event action: count up, count down or index/reset.
on page 69
decoded, and how they can be generated. The QDECs and related features, control and status
register are available for event channel 0, 2 and 4.
Table 6-2.
A quadrature signal is characterized by having two square waves phase shifted 90 degrees rela-
tive to each other. Rotational movement can be measured by counting the edges of the two
waveforms. The phase relationship between the two square waves determines the direction of
rotation.
STROBE
0
0
1
1
summarizes which quadrature decoder data events are available, how they are
DATA
Quadrature Decoder Data Events
0
1
0
1
Data Event User
No Event
Index/Reset
Count Down
Count Up
Signaling Event User
No Event
Signaling Event
Signaling Event
No Event
XMEGA A
Table 6-2
69