MC9S12XD256CAL Datasheet, PDF (964/1348 Pages) Freescale Semiconductor, Inc – This specification describes the function of the clocks and reset generator (CRG).

Chapter 23 DQ256 Port Integration Module (S12XDQ256PIMV2)
23.0.7.4 Port E
Port E is associated with the external bus control outputs R/W, 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] an 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.
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. The clock output is always enabled
in emulation modes.
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 (Section 23.0.5.14, “IRQ
Control Register (IRQCR)”) and clearing the I-bit in the CPU’s condition code register. It is inhibited at
reset so this pin is initially configured as a simple input with a pull-up.
Port E pin PE[0] can be used for either general-purpose input or as the level-sensitive XIRQ interrupt
input. XIRQ can be enabled by clearing the X-bit in the CPU’s condition code register. It is inhibited at
reset so this pin is initially configured as a high-impedance input with a pull-up.
Port E pins PE[5] and PE[6] are configured for reduced input threshold in certain modes (refer to
S12X_EBI section).
23.0.7.5 Port K
Port K pins PK[7:0] can be used for either general-purpose I/O, or, in 144-pin packages, also with the
external bus interface. In this case port K pins PK[6:0] are associated with the external address bus outputs
ADDR22–ADDR16 and PK7 is associated to the EWAIT input.
Port K pin PE[7] is configured for reduced input threshold in certain modes (refer to S12X_EBI section).
NOTE
Port K is not available in 80-pin packages. PK[6] is not available in 112-pin
packages.
23.0.7.6 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.
23.0.7.7 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.
The SPI0 pins can be re-routed. Refer to Section 23.0.5.37, “Module Routing Register (MODRR)”.
MC9S12XDP512 Data Sheet, Rev. 2.21
966
Freescale Semiconductor