Datasheet

Chapter 24 DG128 Port Integration Module (S12XDG128PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.21
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.
76543210
R
PER1AD17 PER1AD16 PER1AD15 PER1AD14 PER1AD13 PER1AD12 PER1AD11 PER1AD10
W
Reset 00000000
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.
Table 24-60. Register Availability per Port
1
Port Data
Data
Direction
Input
Reduced
Drive
Pull
Enable
Polarity
Select
Wired-OR
Mode
Interrupt
Enable
Interrupt
Flag
A yes yes — yes yes — — — —
Byesyes— ————
Eyesyes— ————
Kyesyes— ————
T yes yes yes yes yes — — — —
S yes yes yes yes yes yes yes — —
M yes yes yes yes yes yes yes — —
P yes yes yes yes yes yes — yes yes
H yes yes yes yes yes yes — yes yes