Overview of Capabilities

The Simulator is intended simulate most of the interfacing capabilities of the Motorola 68HC812A4 microcontroller as installed in the Motorola M68HC12A4EVB evaluation board. Timing is simulated to allow estimating performance of the real system. The user interface allows accessing the various 68HC12 features, memories, and execution control. The basic, major capabilities are:

• 16K "External" RAM memory at locations $4000-$7FFF. Adjustable clock stretch.
• 32K "External" pseudo-ROM memory at locations $8000-$FFFF. This memory can be altered via the simulator user interface, and loaded from S19 format files. Adjustable clock stretch.
• Internal memory (RAM and EEPROM) at their default locations, $800-$BFF for the RAM and $1000-$1FFF for the EEPROM. EEPROM can be programatically written.
• Execution can be made to abort on invalid memory reference, invalid instruction execution, and un-handled interrupts.
• 16MHz crystal clock assumed.
• CPU12 fully implemented
• Timer Module implemented, with a "Signal Generator" which can drive any of the inputs.
• COP and RTI implemented
• One SCI implemented, with "turbo mode" optional to allow an infinitely fast data rate.
• ATD implemented
• Peripheral chip selects (CS0 to CS3) implemented
• Ports H and J implemented, including key interrupts
• Output to ports H, J, T (timer), and peripheral chip selects can be logged to a file for analysis.

The simulator can also run in several modes: wide expanded, requested, student, single chip, and simulation of the 68HC912B32 part.