Datasheet

Chapter 2 Port Integration Module (PIM9C32) Block Description
Freescale Semiconductor MC9S12C-Family / MC9S12GC-Family 87
Rev 01.24
2.3.2.2.4 Port S Reduced Drive Register (RDRS)
Read: Anytime.
Write: Anytime.
2.3.2.2.5 Port S Pull Device Enable Register (PERS)
Read: Anytime.
Write: Anytime.
Module Base + 0x000B
76543210
R0000
RDRS3 RDRS2 RDRS1 RDRS0
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 2-13. Port S Reduced Drive Register (RDRS)
Table 2-12. RDRS Field Descriptions
Field Description
3–0
RDRS[3:0]
Reduced Drive Port S — 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.
0 Full drive strength at output.
1 Associated pin drives at about 1/3 of the full drive strength.
Module Base + 0x000C
76543210
R0000
PERS3 PERS2 PERS1 PERS0
W
Reset 0 0 0 01111
= Unimplemented or Reserved
Figure 2-14. Port S Pull Device Enable Register (PERS)
Table 2-13. PERS Field Descriptions
Field Description
3–0
PERS[3:0]
Reduced Drive Port S — 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.
0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.