mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 150

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 3 Port Integration Module (PIM9E256V1)
3.3.5.6
Read: Anytime. Write: Anytime.
The Port S Polarity Select Register selects whether a pull-down or a pull-up device is connected to the pin.
The Port S Polarity Select Register is effective only when the corresponding Data Direction Register bit
is set to 0 (input) and the corresponding Pull Device Enable Register bit is set to 1.
3.3.5.7
Read: Anytime. Write: Anytime.
This register selects whether a port S output is configured as push-pull or wired-OR. When a Wired-OR
Mode Register bit is set to 1, the corresponding output pin is driven active low only (open drain) and a high
level is not driven. A Wired-OR Mode Register bit has no effect if the corresponding pin is configured as
an input.
150
WOMS[7:0]
PPSS[7:0]
Reset
Reset
Field
Field
7:0
7:0
W
W
R
R
WOMS7
PPSS7
Pull Select Port S
0 A pull-up device is connected to the associated port S pin.
1 A pull-down device is connected to the associated port S pin.
Wired-OR Mode Port S
0 Output buffers operate as push-pull outputs.
1 Output buffers operate as open-drain outputs.
Port S Polarity Select Register (PPSS)
Port S Wired-OR Mode Register (WOMS)
0
0
7
7
WOMS6
PPSS6
0
0
6
6
Figure 3-35. Port S Wired-OR Mode Register (WOMS)
Figure 3-34. Port S Polarity Select Register (PPSS)
Table 3-26. WOMS Field Descriptions
Table 3-25. PPSS Field Descriptions
WOMS5
PPSS5
MC9S12E256 Data Sheet, Rev. 1.08
0
0
5
5
WOMS4
PPSS4
0
0
4
4
Description
Description
WOMS3
PPSS3
3
0
3
0
WOMS2
PPSS2
0
0
2
2
WOMS1
PPSS1
Freescale Semiconductor
0
0
1
1
WOMS0
PPSS0
0
0
0
0