MC9S12P128 Datasheet, PDF (103/564 Pages) Freescale Semiconductor, Inc – S12 Microcontrollers

Port Integration Module (S12PPIMV1)
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 flag to enable/disable
the interrupt.
2.4.2.9 Interrupt flag register (PIFx)
If the pin is used as an interrupt input this register holds the interrupt flag after a valid pin event.
2.4.2.10 Module routing register (PTTRR)
This register allows software re-configuration of the pinouts of the different package options for specific
peripherals:
• PTTRR supports the re-routing of the PWM channels to alternative ports
2.4.3
Pins and Ports
NOTE
Please refer to the device pinout section to determine the pin availability in
the different package options.
2.4.3.1 BKGD pin
The BKGD pin is associated with the BDM module.
During reset, the BKGD pin is used as MODC input.
2.4.3.2 Port A, B
Port A pins PA[7:0] and Port B pins PB[7:0] can be used for general purpose I/O.
2.4.3.3 Port E
Port E is associated with the free-running clock outputs ECLK, ECLKX2 and interrupt inputs IRQ and
XIRQ.
Port E pins PE[6:5,3:2] can be used for either general purpose I/O or with the alternative functions.
Port E pin PE[7] an be used for either general purpose I/O or as the free-running clock ECLKX2 output
running at the core clock rate.
Port E pin PE[4] an be used for either general purpose I/O or as the free-running clock ECLK output
running at the bus clock rate or at the programmed divided clock rate.
Port E pin PE[1] can be used for either general purpose input or as the level- or falling edge-sensitive IRQ
interrupt input. IRQ will be enabled by setting the IRQEN configuration bit (2.3.14/2-70) and clearing the
I-bit in the CPU condition code register. It is inhibited at reset so this pin is initially configured as a simple
input with a pull-up.
S12P-Family Reference Manual, Rev. 1.12
Freescale Semiconductor
103