Chapter 2 Port Integration Module (S12ZVHYPIMV1)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
110
Freescale Semiconductor
Figure 2-24. Illustration of I/O pin functionality
2.4.2.4
Pull device enable register (PERx)
This register turns on a pullup or pulldown device on the related pins determined by the associated polarity
select register (
Section 2.4.2.5, “Polarity select register (PPSx)“
”).
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 pullup or pulldown device if enabled.
It becomes only active if the pin is used as an input. A pullup device can be activated if the pin is used as
a wired-or output.
On pins with interrupt functionality this register selects the active edge polarity of the input signal.
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.
PT
DDR
output enable
module enable
1
0
1
1
0
0
PIN
PTI
data out
Module
