MC9S12Q128_10 Datasheet, PDF (86/644 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 2 Port Integration Module (PIM9C32) Block Description
2.3.2.2.4 Port S Reduced Drive Register (RDRS)
Module Base + 0x000B
7
R
0
W
Reset
0
Read: Anytime.
Write: Anytime.
6
5
4
3
2
0
0
0
RDRS3
RDRS2
0
0
0
0
0
= Unimplemented or Reserved
Figure 2-13. Port S Reduced Drive Register (RDRS)
Table 2-12. RDRS Field Descriptions
1
RDRS1
0
0
RDRS0
0
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.
2.3.2.2.5 Port S Pull Device Enable Register (PERS)
Module Base + 0x000C
7
R
0
W
Reset
0
Read: Anytime.
Write: Anytime.
6
5
4
3
2
0
0
0
PERS3
PERS2
0
0
0
1
1
= Unimplemented or Reserved
Figure 2-14. Port S Pull Device Enable Register (PERS)
Table 2-13. PERS Field Descriptions
1
PERS1
1
0
PERS0
1
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.
86
MC9S12Q128
Freescale Semiconductor
Rev 1.10