Analog Devices ADuCM320 Hardware Reference Manual page 92

UG-498
I/O Pull-Up Enable (GPxPUL)
In input mode, GPxPUL enables/disables internal pull-ups/pull-downs. All Port 0 to Port 3 pins have internal pull-ups, and the Port 4 and
Port 5 pins have pull-downs. The pull-ups/pull-downs are implemented as MOS devices, with typical performance shown in Figure 17
and Figure 18.
If a pin is configured as an output, the internal pull-up/pull-down is disabled even in open-drain mode.
I
PULL-UP
80
60
40
20
0
R
OUT
50
40
30
20
10
0 0.5 1.0 1.5
VOLTAGE AT PIN (V)
Figure 17. Typical P0 to P3 Pull-Up Characteristics
I
PULL-DOWN
0
–20
–40
–60
–80
R
OUT
50
40
30
20
10
0 0.5 1.0 1.5
VOLTAGE AT PIN (V)
Figure 18. Typical P4 to P5 Pull-Down Characteristics
Rev. C | Page 92 of 196
ADuCM320 Hardware Reference Manual
2.0 2.5 3.0 3.5
2.0 2.5 3.0 3.5