MC9S12KG128 Datasheet, PDF (150/600 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 4 Port Integration Module (PIM9KG128V1)
4.3.2.4 Port S Reduced Drive Register (RDRS)
Module Base + 0x000B
R
W
Reset
7
RDRS7
0
6
RDRS6
0
5
RDRS5
0
4
RDRS4
0
3
RDRS3
0
2
RDRS2
0
Figure 4-11. Port S Reduced Drive Register (RDRS)
Read: Anytime. Write: Anytime.
1
RDRS1
0
0
RDRS0
0
This register configures the drive strength of each port S output pin as either full or reduced. If the port is
used as input this bit is ignored.
Table 4-8. RDRS Field Descriptions
Field
Description
7–0
Reduced Drive Port S
RDRS[7:0] 0 Full drive strength at output.
1 Associated pin drives at about 1/6 of the full drive strength.
4.3.2.5 Port S Pull Device Enable Register (PERS)
Module Base + 0x000C
7
R
PERS7
W
6
PERS6
5
PERS5
4
PERS4
3
PERS3
2
PERS2
Reset
1
1
1
1
1
1
Figure 4-12. Port S Pull Device Enable Register (PERS)
Read: Anytime. Write: Anytime.
1
PERS1
1
0
PERS0
1
This register configures whether a pull-up or a pull-down device is activated, if the port is used as input or
as output in wired-OR (open drain) mode. This bit has no effect if the port is used as push-pull output. Out
of reset a pull-up device is enabled.
Table 4-9. PERS Field Descriptions
Field
Description
7–0
PERS[7:]
Pull Device Enable Port S
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
MC9S12KG128 Data Sheet, Rev. 1.15
150
Freescale Semiconductor