88
ATmega161(L)
1228B–09/01
Port A pins are tri-stated when a reset condition becomes active, even if the clock is not
running.
Note:
1. n: 7,6…0, pin number
Port A Schematics
Note that all port pins are synchronized. The synchronization latch is, however, not
shown in the figure.
Figure 56.
Port A Schematic Diagrams (Pins PA0 - PA7)
Table 29.
DDAn Effects on Port A Pins
DDAn
PORTAn
I/O
Pull-up
Comment
0
0
Input
No
Tri-state (high-Z)
0
1
Input
Yes
PAn will source current if ext. pulled low.
1
0
Output
No
Push-pull Zero Output
1
1
Output
No
Push-pull One Output