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Chapter 24 DG128 Port Integration Module (S12XDG128PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.17
1028
Freescale Semiconductor
24.0.5.65 Port AD1 Pull Up Enable Register 1 (PER1AD1)
Read: Anytime.
Write: Anytime.
This register activates a pull-up device on the respective PAD[7:0] pin if the port is used as input. This bit
has no effect if the port is used as output. Out of reset no pull-up device is enabled.
Functional Description
Each pin except PE0, PE1, and BKGD can act as general purpose I/O. In addition each pin can act as an
output from the external bus interface module or a peripheral module or an input to the external bus
interface module or a peripheral module.
A set of configuration registers is common to all ports with exceptions in the expanded bus interface and
ATD ports (
Table 24-60
). All registers can be written at any time; however a specific configuration might
not become active.
Example: Selecting a pull-up device
This device does not become active while the port is used as a push-pull output.
Table 24-60. Register Availability per Port
1
7
6
5
4
3
2
1
0
R
PER1AD17
PER1AD16
PER1AD15
PER1AD14
PER1AD13
PER1AD12
PER1AD11
PER1AD10
W
Reset
0
0
0
0
0
0
0
0
Figure 24-67. Port AD1 Pull Up Enable Register 1 (PER1AD1)
Table 24-59. PER1AD1 Field Descriptions
Field
Description
7–0
PER1AD1
[7:0]
Pull Device Enable Port AD1 Register 1
0 Pull-up device is disabled.
1 Pull-up device is enabled.
Port
Data
Data
Direction
Input
Reduced
Drive
Pull
Enable
Polarity
Select
Wired-OR
Mode
Interrupt
Enable
Interrupt
Flag
A
B
E
K
T
S
M
P
H
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
—
—
—
—
yes
yes
yes
yes
yes
yes
yes
—
—
—
—
—
yes
yes
yes
yes
—
—
—
—
—
yes
yes
—
—
—
—
—
—
—
—
—
yes
yes
—
—
—
—
—
—
—
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes