Chapter 4 Port Integration Module (S12XDP512PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.11
220 Freescale Semiconductor
4.3.2.26 Port S Reduced Drive Register (RDRS)
Read: Anytime.
Write: Anytime.
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.
4.3.2.27 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, 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.
0x024B
76543210
R
RDRS7 RDRS6 RDRS5 RDRS4 RDRS3 RDRS2 RDRS1 RDRS0
W
Reset 00000000
Figure 4-28. Port S Reduced Drive Register (RDRS)
Table 4-28. 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 1/6 of the full drive strength.
0x024C
76543210
R
PERS7 PERS6 PERS5 PERS4 PERS3 PERS2 PERS1 PERS0
W
Reset 11111111
Figure 4-29. Port S Pull Device Enable Register (PERS)
Table 4-29. 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 Either a pull-up or pull-down device is enabled.