mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 86

• Manufacturer Part Number: mc9s12q128
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 2 Port Integration Module (PIM9C32) Block Description
2.3.2.2.4
Read: Anytime.
Write: Anytime.
2.3.2.2.5
Read: Anytime.
Write: Anytime.
86
Module Base + 0x000B
Module Base + 0x000C
RDRS[3:0]
PERS[3:0]
Reset
Reset
Field
Field
3–0
3–0
W
W
R
R
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.
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.
0
0
0
0
7
7
Port S Reduced Drive Register (RDRS)
Port S Pull Device Enable Register (PERS)
= Unimplemented or Reserved
= Unimplemented or Reserved
Figure 2-14. Port S Pull Device Enable Register (PERS)
0
0
0
0
6
6
Figure 2-13. Port S Reduced Drive Register (RDRS)
Table 2-12. RDRS Field Descriptions
Table 2-13. PERS Field Descriptions
0
0
0
0
5
5
MC9S12Q128
Rev 1.09
0
0
0
0
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