mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 846

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 22 DP512 Port Integration Module (S12XDP512PIMV2)
22.3.2.26 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.
22.3.2.27 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.
846
RDRS[7:0]
PERS[7:0]
Reset
Reset
Field
Field
7–0
7–0
W
W
R
R
RDRS7
PERS7
Reduced Drive Port S
0 Full drive strength at output.
1 Associated pin drives at about 1/6 of the full drive strength.
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.
0
1
7
7
RDRS6
PERS6
Figure 22-29. Port S Pull Device Enable Register (PERS)
0
1
6
6
Figure 22-28. Port S Reduced Drive Register (RDRS)
Table 22-28. RDRS Field Descriptions
Table 22-29. PERS Field Descriptions
RDRS5
PERS5
MC9S12XDP512 Data Sheet, Rev. 2.17
0
1
5
5
RDRS4
PERS4
0
1
4
4
Description
Description
RDRS3
PERS3
0
1
3
3
RDRS2
PERS2
0
1
2
2
RDRS1
PERS1
Freescale Semiconductor
0
1
1
1
RDRS0
PERS0
0
1
0
0