Datasheet

61
8024A–AVR–04/08
ATmega8HVA/16HVA
14.4.1 Alternate Functions of Port C
The Port C pins with alternate functions are shown in Table 14-2.
The alternate pin configuration is as follows:
• INT0 - Port C, Bit 0
INT0: External Interrupt Source 0. The PC0 pin can serve as external interrupt source. INT0 can
be used as an interrupt pin regardless of whether another special function is enabled or not.
Table 14-3 relates the alternate functions of Port C to the overriding signals shown in Figure 14-
3 on page 60.
Table 14-1. Generic Description of Overriding Signals for Alternate Functions
Signal Name Full Name Description
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.
Table 14-2. Port C Pins Alternate Functions
Port Pin Alternate Function
PC0 INT0/ ICP0 (External Interrupt 0 or Timer/Counter0 Input Capture Trigger)
Table 14-3. Overriding Signals for Alternate Functions in PC0
Signal Name PC0/INT0
PVOE 0
DIEOE INT Enable
DIEOV 1
DI INT0 INPUT