35
AT90S1200
0838H–AVR–03/02
Note:
n: 6…0, pin number.
Alternate Functions for Port D
The alternate functions of Port D are:
• T0 – Port D, Bit 4
T0, Timer/Counter0 clock source. See the timer description for further details.
• INT0 – Port D, Bit 2
INT0, External Interrupt source 0. See the interrupt description for further details.
Port D Schematics
Note that all port pins are synchronized. The synchronization latches are, however, not
shown in the figures.
Figure 27.
Port D Schematic Diagram (Pins PD0, PD1, PD3, PD5, and PD6)
Table 11.
DDDn Bits’ Effect on Port D Pins
DDDn
PORTDn
I/O
Pull-up
Comment
0
0
Input
No
Tri-state (High-Z)
0
1
Input
Yes
PDn will source current if ext. pulled low.
1
0
Output
No
Push-pull Zero Output
1
1
Output
No
Push-pull One Output