S912XEG128J2MAA Datasheet, PDF (181/1324 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2 Port Integration Module (S12XEPIMV1)
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 (MODRR, PTRRR, PTLRR, PTFRR)
This register supports the re-routing of the CAN0, CAN4, SPI2-0, SCI7-3, IIC0, TIM and CS[3:0] pins to
alternative ports. This allows a software re-configuration of the pinouts of the different package options
with respect to above peripherals.
2.4.3
Pins and Ports
NOTE
Please refer to the SOC Guide to determine the pin availability in the
different package options.
2.4.3.1 BKGD pin
The BKGD pin is associated with the S12X_BDM and S12X_EBI modules.
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 either general-purpose I/O with the external
bus interface. In this case Port A and Port B are associated with the external address bus outputs ADDR15-
ADDR8 and ADDR7-ADDR0, respectively. PB0 is the ADDR0 or UDS output.
2.4.3.3 Port C, D
Port C pins PC[7:0] and Port D pins PD[7:0] can be used for either general-purpose I/O with the external
bus interface. In this case Port C and Port D are associated with the external data bus inputs/outputs
DATA15-DATA8 and DATA7-DATA0, respectively.
These pins are configured for reduced input threshold in certain operating modes (refer to S12X_EBI
section).
2.4.3.4 Port E
Port E is associated with the external bus control outputs RW, LSTRB, LDS and RE, the free-running clock
outputs ECLK and ECLK2X, as well as with the TAGHI, TAGLO, MODA and MODB and interrupt inputs
IRQ and XIRQ.
Port E pins PE[7:2] can be used for either general-purpose I/O or with the alternative functions.
Port E pin PE[7] can be used for either general-purpose I/O or as the free-running clock ECLKX2 output
running at the Core Clock rate. The clock output is always enabled in emulation modes.
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor
181