
Chapter 23 DQ256 Port Integration Module (S12XDQ256PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.17
962
Freescale Semiconductor
23.0.5.73 Port AD1 Pull Up Enable Register 1 (PER1AD1)
Read: Anytime.
Write: Anytime.
This register activates a pull-up device on the respective PAD[15:8] 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 23-67
). 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 23-67. Register Availability per Port
1
7
6
5
4
3
2
1
0
R
PER1AD115 PER1AD114 PER1AD113 PER1AD112 PER1AD111 PER1AD110
PER1AD19
PER1AD18
W
Reset
0
0
0
0
0
0
0
0
Figure 23-75. Port AD1 Pull Up Enable Register 1 (PER1AD1)
Table 23-66. PER1AD1 Field Descriptions
Field
Description
7–0
PER1AD1
[15:8]
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
C
D
E
K
T
S
M
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