mc9s12vr48 Freescale Semiconductor, Inc, mc9s12vr48 Datasheet - Page 91

• Manufacturer Part Number: mc9s12vr48
• Description: S12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Independent of the pin usage with a peripheral module this register determines the source of data when
reading the associated data register address (2.4.2.1/2-90).
2.4.2.4
If the pin is used as an output this register allows the configuration of the drive strength independent of the
use with a peripheral module.
2.4.2.5
This register turns on a pullup or pulldown device on the related pins determined by the associated polarity
select register (2.4.2.6/2-91).
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.
2.4.2.6
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.
Freescale Semiconductor
Reduced drive register (RDRx)
Pull device enable register (PERx)
Polarity select register (PPSx)
Due to internal synchronization circuits, it can take up to 2 bus clock cycles
until the correct value is read on port data or port input registers, when
changing the data direction register.
Module
Figure 2-45. Illustration of I/O pin functionality
DDR
PTI
MC9S12VR Family Reference Manual, Rev. 2.2
PT
Preliminary - Subject to Change Without Notice
data out
output enable
module enable
1
0
1
1
NOTE
0
0
PIN
Port Integration Module (S12VRPIMV2)
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