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S912XEG384J3VA Datasheet, PDF (180/1324 Pages) Freescale Semiconductor, Inc – MC9S12XEP100 Reference Manual Covers MC9S12XE Family | |||
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Chapter 2 Port Integration Module (S12XEPIMV1)
PTI
0
1
PT
0
1
PIN
DDR
0
1
data out
Module output enable
module enable
Figure 2-107. Illustration of I/O pin functionality
2.4.2.4 Reduced drive register (RDRx)
If the pin is used as an output this register allows the conï¬guration of the drive strength.
2.4.2.5 Pull device enable register (PERx)
This register turns on a pull-up or pull-down device.
It becomes active only if the pin is used as an input or as a wired-or output.
2.4.2.6 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.
2.4.2.7 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.
2.4.2.8 Interrupt enable register (PIEx)
If the pin is used as an interrupt input this register serves as a mask to the interrupt ï¬ag to enable/disable
the interrupt.
MC9S12XE-Family Reference Manual Rev. 1.25
180
Freescale Semiconductor
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