Datasheet

Table 18-2. Generic Description of Overriding Signals for Alternate Functions
Signal Name Full Name Description
PUOE Pull-up Override
Enable
If this signal is set, the pull-up enable is controlled by the PUOV signal.
If this signal is cleared, the pull-up is enabled when {DDxn, PORTxn,
PUD} = 0b010.
PUOV Pull-up Override Value If PUOE is set, the pull-up is enabled/disabled when PUOV is set/
cleared, regardless of the setting of the DDxn, PORTxn, and PUD
Register bits.
DDOE Data Direction
Override Enable
If this signal is set, the Output Driver Enable is controlled by the DDOV
signal. If this signal is cleared, the Output driver is enabled by the DDxn
Register bit.
DDOV Data Direction
Override Value
If DDOE is set, the Output Driver is enabled/disabled when DDOV is
set/cleared, regardless of the setting of the DDxn Register bit.
PVOE Port Value Override
Enable
If this signal is set and the Output Driver is enabled, the port value is
controlled by the PVOV signal. If PVOE is cleared, and the Output
Driver is enabled, the port Value is controlled by the PORTxn Register
bit.
PVOV Port Value Override
Value
If PVOE is set, the port value is set to PVOV, regardless of the setting of
the PORTxn Register bit.
DIEOE Digital Input Enable
Override Enable
If this bit is set, the Digital Input Enable is controlled by the DIEOV
signal. If this signal is cleared, the Digital Input Enable is determined by
MCU state (Normal mode, sleep mode).
DIEOV Digital Input Enable
Override Value
If DIEOE is set, the Digital Input is enabled/disabled when DIEOV is set/
cleared, regardless of the MCU state (Normal mode, sleep mode).
DI Digital Input This is the Digital Input to alternate functions. In the figure, the signal is
connected to the output of the Schmitt Trigger but before the
synchronizer. Unless the Digital Input is used as a clock source, the
module with the alternate function will use its own synchronizer.
AIO Analog Input/Output This is the Analog Input/output to/from alternate functions. The signal is
connected directly to the pad, and can be used bi-directionally.
The following subsections shortly describe the alternate functions for each port, and relate the overriding
signals to the alternate function. Refer to the alternate function description for further details.
18.3.1 Alternate Functions of Port B
The Port B pins with alternate functions are shown in the table below:
Table 18-3. Port B Pins Alternate Functions
Port Pin Alternate Functions
PB7 XTAL2 (Chip Clock Oscillator pin 2)
TOSC2 (Timer Oscillator pin 2)
PB6 XTAL1 (Chip Clock Oscillator pin 1 or External clock input)
TOSC1 (Timer Oscillator pin 1)
AVR 8-Bit Microcontroller
I/O Ports
© 2017 Microchip Technology Inc.
Datasheet Complete
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