Datasheet

Chapter 3 Port Integration Module (PIM9E128V1)
MC9S12E128 Data Sheet, Rev. 1.07
150 Freescale Semiconductor
3.3.5.4 Port S Reduced Drive Register (RDRS)
Read: Anytime. Write: Anytime.
This register configures the drive strength of configured output pins as either full or reduced. If a pin is
configured as input, the corresponding Reduced Drive Register bit has no effect.
3.3.5.5 Port S Pull Device Enable Register (PERS)
Read: Anytime. Write: Anytime.
This register configures whether a pull-up or a pull-down device is activated on configured input or
wired-or (open drain) output pins. If a pin is configured as push-pull output, the corresponding Pull Device
Enable Register bit has no effect.
76543210
R
RDRS7 RDRS6 RDRS5 RDRS4 RDRS3 RDRS2 RDRS1 RDRS0
W
Reset 0 0 0 00000
Figure 3-32. Port S Reduced Drive Register (RDRS)
Table 3-23. RDRS Field Descriptions
Field Description
7:0
RDRS[7:0]
Reduced Drive Port S
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
76543210
R
PERS7 PERS6 PERS5 PERS4 PERS3 PERS2 PERS1 PERS0
W
Reset 1 1 1 11111
= Reserved or Unimplemented
Figure 3-33. Port S Pull Device Enable Register (PERS)
Table 3-24. PERS Field Descriptions
Field Description
7:0
PERS[7:0]
Pull Device Enable Port S
0 Pull-up or pull-down device is disabled.
1 Pull-up or pull-down device is enabled.