THRSim11 68HC11 Simulator for Windows.

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Copyright © 2013 Harry Broeders. Version 5.30 April 2013
What's new in version 5.30?

The Motorola 68HC11 microcontroller was a popular microcontroller used in many applications. With the THRSim11 program you can edit, assemble, simulate and debug programs for the 68HC11 on your windows PC. You can also use THRSim11 to debug the program on your target EVM or EVB compatable board. The simulator simulates the CPU, ROM, RAM, and all memory mapped I/O ports. It also simulates the on board peripherals such as:

• timer (including pulse accumulator),
• analog to digital converter,
• parallel ports (including handshake),
• serial port,
• I/O pins (including analog and interrupt pins).

While debugging the graphical user interface makes it possible to view and control every register (CPU registers and I/O registers), memory location (data, program, and stack), and pin of the simulated microcontroller. Even when the program is running! It is possible to stop the simulation at any combination of events. For example: stop when RxD becomes low and RAM location $003F contains $BD or I/O register TCNT is greater than $3456.

A number of (simulated) external components can be connected to the pins of the simulated 68HC11 while debugging. For example:

• LED's,
• switches,
• analog sliders (variable voltage potential).
• serial transmitter and receiver.
• many more... see the THRSim11 components page.

There is also a 4 x 20 LCD character display mapped in the address space of the 68HC11.

THRSim11 can communicate with the Motorola EVM and EVB boards or with any other board running the BUFFALO monitor program. This monitor program can be downloaded (for free) from the Motorola website. When your assembly program is loaded into the target board the graphical user interface makes it possible to view and control every register (CPU registers and I/O registers) and memory location (data, program, and stack) of the real microcontroller. It is possible to stop the execution at any address and inspect or change the registers and memory.

For high level language (C/C++) support THRSim11 has a debugger that reads object files with debug info in the DWARF2 debug format used by the free GNU gcc compiler. C variables are also updated while running the program. More information on debugging GNU gcc C/C++ or as assembler programs with THRSim11 is available here.

Information about THRAss11.

 Technical specifications of the THRSim11 68HC11 Simulator:

• nearly Complete simulation of the Motorola 68HC11A8 microcontroller.
• Complete instruction-set simulation.
• nearly Complete simulation of the registerset.
  •  CPU registers: A, B, D, X, Y, SP (stack pointer), PC (program counter) and CCR (condition code register).
  •  Port registers: PORTA, PORTB, PORTC, PORTCL, PIOC, PORTD, PORTE, DDRC and DDRD.
  •  Timer registers: TCNT, TIC1, TIC2, TIC3, TOC1, TOC2, TOC3, TOC4, TOC5, TCTL1, TCTL2, TMSK1, TFLG1, TMSK2 and TFLG2.
  •  Serial registers: BAUD, SCCR1, SCCR2, SCSR and SCDR.
  •  Pulse accumulator registers: PACTL and PACNT.
  •  AD converter registers: ADCTL, ADR1, ACR2, ADR3 and ADR4.
  •  Handshake registers: PIOC, PORTB, PORTC and PORTCL.
  •  Other registers: CONFIG, COPRST, HPRIO, INIT, OPTIONS and PPROG.
    • CONFIG register can only be changed by using the thrsim11_options.txt file and can be used to enable the COP system which is fully simulated.
    • COPRST register must be used to reset the COP timer regulary when the COP system is enabled.
    • HPRIO register can be used to select a high priority interrupt.
    • INIT register can be used to remap the location of RAM and the location of the I/O registers.
    • OPTION register can be used to select the sensitivity of the IRQ input, to power up the ADC, and to select the COP timer rate. 
•   nearly Complete simulation of memory.
  • 0.25 KBytes of RAM ($0000 to $00FF). Extensible in the licensed version to a maximum of 64KByte ($0000 to $FFFF).
  • 0.25 KBytes of ROM ($FF00 to $FFFF). Extensible in the licensed version to a maximum of 64KBytes ($0000 to $FFFF).
• nearly Complete I/O simulation.
  •  Simulation of all pins.
    • PA0 to PA7 (including the IC1 to IC3 and OC1 to OC5 function).
    • PB0 to PB7.
    • PC0 to PC7.
    • PD0 to PD5 (including the RxD and TxD function).
    • PE0 to PE7 (analog pins).
    • IRQ and XIRQ
    • RESET
    • STRA and STRB
    • Vr_L and Vr_H (analog pins).
  •  Timer (including pulse accumulator).
  •  Analog to Digital Converter.
  •  Parallel ports (including handshake).
  •  Serial port.
• Simulation of some external hardware.
  •  THRSim11 I/O box. See this screenshot.
    • LED's (PB0 to PB7, PD0 to PD5 and STRA).
    • Switches (PC0 to PC7 and STRA).
    • 4 x 20 LCD character display.
  •   Resistance measurement. See this screenshot.
  •   Capacity measurement. See this screenshot.
  •  Analog sliders. See this screenshot.
  •   Serial transmitter and receiver. See this screenshot.
• Simulator Graphical User Interface (GUI). See this screenshot.
  •  Register windows (CPU and I/O registers) with edit, trace and breakpoint capabilities.
  •  Pin windows with edit, trace and breakpoint capabilities.
  •  Memory window with edit, trace and breakpoint capabilities.
  •  Custom made window with the registers (CPU and or I/O), memory places and pins you want to combine! And you still have edit, trace and breakpoint capabilities. You can even remove or add registers, memory places and/or pins.
  •   List window with breakpoints, tracing and single stepping.
  •  Disassembler window (e.g. to trace self modifying code).
  •  Memory dump window for an broader overview with edit capabilities.
  •  Stack window with edit, trace and breakpoint capabilities.
  •   Command window with edit and redo capabilities. About 50 commands including HELP.
  •  Label window with edit, add and remove capabilities.
  •  Breakpoint window with edit, add and remove capabilities.
• Target Board Graphical User Interface (GUI). See this screenshot.
  •  Target Register windows (CPU and I/O registers) with edit and trace capabilities.
  •  Target Memory window with edit and trace capabilities.
  •  Target custom made window with the target registers (CPU and or I/O) and target memory places you want to combine! And you still have edit, trace and breakpoint capabilities. You can even remove or add target registers or target memory places.
  •   List window with breakpoints, tracing and single stepping. The target board's PC can also be traced in the simulator's list window.
  •  Target Disassembler window (e.g. to trace self modifying code).
  •  Target Memory dump window for an broader overview with edit capabilities.
  •  Target Stack window with edit and trace capabilities.
  •   Target Command window with edit and redo capabilities. All EVB or EVM commands plus severall extra commands.
  •  Label window with edit, add and remove capabilities. All labels can be used in target commands also.
  •  Target Breakpoint list with add and remove menu items.
•   Integrated assembler and editor with drag and drop support.
• Support for debugging C programs compiled with GNU gcc for 68HC11.
• Support for debugging 68HC11 assembler programs compiled with GNU as for 68HC11.
• Complete help file including context sensitive help.
• A lot of components that you can download and plug into THRSim11.
• THRSim11 CDK (Component Development Kit) which you can use to develop your own components.

Installation of THRSim11:

• Download this EXE file and start it to install THRSim11.

Making a small payment to compensate for the work involved.

THRSim11 is free of charge. But a small payment to compensate for the work involved is appreciated. To make a small payment click here. To get more information about the THRSim11. Please contact:

Harry Broeders
Mariniersweg 24
3255 VG  Oude Tonge
The Netherlands
Tel: +31 187641143
E-mail: harry@hc11.demon.nl