Port Integration Module (S12XHYPIMV1)
MC9S12XHY-Family Reference Manual, Rev. 1.01
152
Freescale Semiconductor
Figure 2-94. Illustration of I/O pin functionality
2.4.2.4
Pull device enable register (PERx)
This register turns on a pull-up or pull-down device on the related pins determined by the associated
polarity select register (
2.4.2.5/2-152
).
The pull device becomes active only if the pin is used as an input or as a wired-or output. Some peripheral
module only allow certain configurations of pull devices to become active. Refer to the respective bit
descriptions.
2.4.2.5
Polarity select register (PPSx)
This register selects either a pull-up or pull-down device if enabled.
It becomes only active if the pin is used as an input. A pull-up device can be activated if the pin is used as
a wired-or output.
2.4.2.6
Wired-or mode register (WOMx)
If the pin is used as an output this register turns off the active high drive. This allows wired-or type
connections of outputs.
2.4.2.7
Interrupt enable register (PIEx)
If the pin is used as an interrupt input this register serves as a mask to the interrupt flag to enable/disable
the interrupt.
2.4.2.8
Interrupt flag register (PIFx)
If the pin is used as an interrupt input this register holds the interrupt flag after a valid pin event.
PT
DDR
output enable
module enable
1
0
1
1
0
0
PIN
PTI
data out
Module
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