MC3S12RG128 Datasheet, PDF (109/546 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2 Port Integration Module (PIM3RG128V1) Block Description
2.4.4 Reduced Drive Register
If the port is used as an output the register allows the configuration of the drive strength.
2.4.5 Pull Device Enable Register
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.
2.4.6 Polarity Select Register
This register selects either a pull-up or pull-down device if enabled. It becomes active only 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.
2.4.7 Port T
This port is associated with the ECT module.
Port T pins PT[7:0] can be used for either general-purpose I/O, or with the channels of the Enhanced
Capture Timer. During reset, port T pins are configured as high-impedance inputs.
2.4.8 Port S
This port is associated with SCI0, SCI1, and SPI0.
Port S pins PS[7:0] can be used either for general-purpose I/O, or with the SCI and SPI subsystems. During
reset, port S pins are configured as inputs with pull-up.
The SPI0 pins can be re-routed. Refer to Figure 2-23.
2.4.9 Port M
This port is associated with the CAN4, CAN0, and SPI0.
Port M pins PM[7:0] can be used for either general purpose I/O, or with the CAN and SPI subsystems.
During reset, port M pins are configured as high-impedance inputs.
The CAN0, CAN4, and SPI0 pins can be re-routed. Refer to Figure 2-23.
2.4.9.1 Module Routing Register
This register allows to re-route the CAN0, CAN4, SPI0, and SPI1 pins to predefined pins.
NOTE
The purpose of the Module Routing Register is to provide maximum
flexibility for future derivatives of the MC3S12RG128 with a lower number
of MSCAN and SPI modules.
MC3S12RG128 Data Sheet, Rev. 1.05
Freescale Semiconductor
109