S912XHY128F0VLM Datasheet, PDF (152/802 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

Port Integration Module (S12XHYPIMV1)
PTI
0
1
PT
0
1
PIN
DDR
0
1
data out
Module _{output enable}
module enable
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.
MC9S12XHY-Family Reference Manual, Rev. 1.01
152
Freescale Semiconductor