S912XEG384J3VA Datasheet, PDF (63/1324 Pages) Freescale Semiconductor, Inc – MC9S12XEP100 Reference Manual Covers MC9S12XE Family

Chapter 1 Device Overview MC9S12XE-Family
1.2.3.7 PA[7:0] / ADDR[15:8] / IVD[15:8] — Port A I/O Pins
PA[7:0] are general-purpose input or output pins. In MCU expanded modes of operation, these pins are
used for the external address bus. In MCU emulation modes of operation, these pins are used for external
address bus and internal visibility read data.
1.2.3.8 PB[7:1] / ADDR[7:1] / IVD[7:1] — Port B I/O Pins
PB[7:1] are general-purpose input or output pins. In MCU expanded modes of operation, these pins are
used for the external address bus. In MCU emulation modes of operation, these pins are used for external
address bus and internal visibility read data.
1.2.3.9 PB0 / ADDR0 / UDS / IVD[0] — Port B I/O Pin 0
PB0 is a general-purpose input or output pin. In MCU expanded modes of operation, this pin is used for
the external address bus ADDR0 or as upper data strobe signal. In MCU emulation modes of operation,
this pin is used for external address bus ADDR0 and internal visibility read data IVD0.
1.2.3.10 PC[7:0] / DATA [15:8] — Port C I/O Pins
PC[7:0] are general-purpose input or output pins. In MCU expanded modes of operation, these pins are
used for the external data bus.
The input voltage thresholds for PC[7:0] can be configured to reduced levels, to allow data from an external
3.3-V peripheral to be read by the MCU operating at 5.0 V. The input voltage thresholds for PC[7:0] are
configured to reduced levels out of reset in expanded and emulation modes. The input voltage thresholds
for PC[7:0] are configured to 5-V levels out of reset in normal modes.
1.2.3.11 PD[7:0] / DATA [7:0] — Port D I/O Pins
PD[7:0] are general-purpose input or output pins. In MCU expanded modes of operation, these pins are
used for the external data bus.
The input voltage thresholds for PD[7:0] can be configured to reduced levels, to allow data from an
external 3.3-V peripheral to be read by the MCU operating at 5.0 V. The input voltage thresholds for
PD[7:0] are configured to reduced levels out of reset in expanded and emulation modes. The input voltage
thresholds for PC[7:0] are configured to 5-V levels out of reset in normal modes.
1.2.3.12 PE7 / ECLKX2 / XCLKS — Port E I/O Pin 7
PE7 is a general-purpose input or output pin. ECLKX2 is a free running clock of twice the internal bus
frequency, available by default in emulation modes and when enabled in other modes. The XCLKS is an
input signal which controls whether a crystal in combination with the internal loop controlled Pierce
oscillator is used or whether full swing Pierce oscillator/external clock circuitry is used (refer to Oscillator
Configuration). An internal pullup is enabled during reset.
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor
63