S912XEP100J5MAG Datasheet, PDF (222/1324 Pages) Freescale Semiconductor, Inc – Features of the MC9S12XE-Family are listed here. Please see Table D-2.for memory options and Table D-2. for the peripheral features that are available on the different family members.

Chapter 3 Memory Mapping Control (S12XMMCV4)
MCU
No External Bus
Flash
Figure 3-24. ROM in Single Chip Modes
3.5.3.2 ROM Control in Emulation Single-Chip Mode
In emulation single-chip mode the external bus is connected to the emulator. If the EROMON bit is set,
the internal FLASH provides the data and the emulator can observe all internal CPU actions on the external
bus. If the EROMON bit is cleared, the emulator provides the data (generator) and traces the all CPU
actions (see Figure 3-25).
MCU
Emulator
Observer
Flash
MCU
EROMON = 1
Emulator
Generator
Flash
EROMON = 0
Figure 3-25. ROM in Emulation Single-Chip Mode
3.5.3.3 ROM Control in Normal Expanded Mode
In normal expanded mode the external bus will be connected to the application. If the ROMON bit is set,
the internal FLASH provides the data. If the ROMON bit is cleared, the application memory provides the
data (see Figure 3-26).
MC9S12XE-Family Reference Manual Rev. 1.25
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Freescale Semiconductor