Datasheet

33XMEGA A4U [DATASHEET]
Atmel-8387G-AVR-ATxmega16A4U-34A4U-64A4U-128A4U-Datasheet_03/2014
15.4 Input sensing
Input sensing is synchronous or asynchronous depending on the enabled clock for the ports, and the configuration is
shown in Figure 15-7.
Figure 15-7. Input sensing system overview.
When a pin is configured with inverted I/O, the pin value is inverted before the input sensing.
15.5 Alternate Port Functions
Most port pins have alternate pin functions in addition to being a general purpose I/O pin. When an alternate function
is enabled, it might override the normal port pin function or pin value. This happens when other peripherals that
require pins are enabled or configured to use pins. If and how a peripheral will override and use pins is described in
the section for that peripheral. “Pinout and Pin Functions” on page 54 shows which modules on peripherals that
enable alternate functions on a pin, and which alternate functions that are available on a pin.
INVERTED I/O
Interrupt
Control
IREQ
Event
Pn
D
Q
R
D
Q
R
Synchronizer
INn
EDGE
DETECT
Asynchronous sensing
Synchronous sensing
EDGE
DETECT