mc9s12xd256 Freescale Semiconductor, Inc, mc9s12xd256 Datasheet - Page 687

• Manufacturer Part Number: mc9s12xd256
• Description: Hcs12x Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

18.5.3
The MCU offers two modes to support emulation. In the first mode (called generator) the emulator
provides the data instead of the internal FLASH and traces the CPU actions. In the other mode (called
observer) the internal FLASH provides the data and all internal actions are made visible to the emulator.
18.5.3.1
In single-chip modes the MCU has no external bus. All memory accesses and program fetches are internal
(see
18.5.3.2
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
Freescale Semiconductor
Figure
18-27).
On-Chip ROM Control
Figure
ROM Control in Single-Chip Modes
ROM Control in Emulation Single-Chip Mode
18-28).
MCU
MCU
Figure 18-28. ROM in Emulation Single-Chip Mode
Figure 18-27. ROM in Single Chip Modes
Flash
MCU
MC9S12XDP512 Data Sheet, Rev. 2.17
Flash
No External Bus
Emulator
Emulator
Chapter 18 Memory Mapping Control (S12XMMCV3)
EROMON = 1
EROMON = 0
Flash
Generator
Observer
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