mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 140

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

Chapter 3 Port Integration Module (PIM9E256V1)
3.3.2.7
Read: Anytime. Write: Anytime.
This register selects whether a port M 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.
These bits apply also to the SCI2 outputs and allow a multipoint connection of several serial modules.
If the IIC is enabled, the associated pins are always set to wired-OR mode, and the state of the
WOMM[7:6] bits have no effect. The WOMM[7:6] bits will not change to reflect their wired-OR mode
configuration when the IIC is enabled.
140
WOMM[7:4]
Reset
Field
7:4
W
R
WOMM7
Wired-OR Mode Port M
0 Output buffers operate as push-pull outputs.
1 Output buffers operate as open-drain outputs.
Port M Wired-OR Mode Register (WOMM)
0
7
= Reserved or Unimplemented
WOMM6
0
6
Figure 3-16. Port M Wired-OR Mode Register (WOMM)
Table 3-13. WOMM Field Descriptions
WOMM5
MC9S12E256 Data Sheet, Rev. 1.08
0
5
WOMM4
0
4
Description
3
0
0
0
0
2
Freescale Semiconductor
0
0
1
0
0
0