Chapter 3 - User Guide

The miSim DE window is divided into three areas. Along the top there are menu buttons and buttons which control simulation. In the middle there are a series of tabbed windows. Along the bottom of the window is the status bar which reports the current state of miSim DE.

Menu Buttons

The File menu has the following options:

• New Creates a new tab window with an empty file for editing
• Open.. Opens an existing source (.asm) file for editing or assembling
• Save Saves the currently chosen edit window
• Save As.. Saves the currently chosen edit window with a new filename
• Close Closes the currently chosen edit window
• Assemble Assembles the currenly chosen edit window
• Load Binary.. Loads a binary (.hex) file into the simulator
• Save Binary.. Saves a binary or assembled file in .hex format
• Program Device Invoke the device programmer with the current binary or assembled file
• Update.. Check for latest updates and Plugins and install selected components
• Quit Quits miSim DE

The Edit menu has following options:

• Undo Undo the last change to the current edit window
• Redo Redo the last undone change
• Cut Cut the selected text from the current edit window and copy it to the clipboard
• Copy Copy the selected text from the current edit window to the clipboard
• Paste Paste the clipboard contents into the current edit window at the cursor position
• Search Search for a string in the current edit window
• Search Again Repeat the last search again
• Goto Line Goto a specific line number in the current edit window
• Preferences Edit miSim DE Preferences

The Debug menu has these options:

• Goto Address Set the PC register to a new value
• Add Breakpoint Add a new breakpoint
• Remove Breakpoint Remove an existing breakpoint
• Edit Breakpoints.. Display all current breakpoints so they may be edited
• Clear Breakpoints.. Clear (remove) all current breakpoints.

Simulation Control Buttons

The Simulation controls include the following buttons:

	Resets the simulation and sets the program counter to 0
	Displays the current instruction about to be simulated in the View window.
	Step - Executes exactly one instruction (but see below for more information)
	Over - Normally executes one instruction, but if that instruction is a call or a loop instruction, the entire called routine or loop is executed.
	Runs the simulation continuously
	Stops the simulation

For both Step and Over, the number of machine cycles simulated are shown in the status bar at the bottom of the miSim DE window. Note that if the 'fast loop simulation' is selected (in the Preferences dialog), Step will execute any empty DECSNZ/GOTO delay loops as a single operation and report the number of machine cycles that the delay loop took.

Tab Buttons

• The Log window which reports actions carried out such as loading files or running the simulator.
• The Processor window which displays the instructions loaded into the processor.
• The Plugin window which allows Plugins to be displayed and configured.

In addition, Edit Windows can be opened to edit or view text or source files.

The Log Window shows a scrollable list of actions that have been carried out by the simulator. This includes loading files, assembling and assembly errors and running the simulator itself. The log view cannot be edited or saved.

The Processor window shows the contents of the processor memory and if the contents were loaded by assembling a file, relates them to the assembly listing that generated them. The tab for the processor window will show the name for the emulated processor. This will change either when a different processor is selected in the preferences dialog, or when an assembled file specifies a different processor (using the LIST or PROCESSOR commands).

The main part of the Processor window shows an assembly listing of the program loaded into the simulated processor. A typical assembly listing looks something like this:

The listing shows a number of columns, depending on whether it was generated by assembling a source code file, or disassembled from a binary (.hex) file. In both views, the leftmost column will contain green indicators for lines that are set as breakpoints. In this view and edit windows, orange indicators are used to show lines that contain one or more warnings, and red indicators show lines that contain one or more errors.

Each line will then start either with an address (a four digit hex number) followed by one or more data values (again, four digit hex values) or an eight digit hex number representing the result of an assignment operation (such as the EQU or SET commands). If the listing was generated by an assembled source file, the next column will be the decimal line number of the original source file.

After these columns, the window contains the assembly text that was used to generate the binary data. This text is colour highlighted as with the edit window.

Along the bottom of the Processor window is information about the processor's current state. The program counter (PC) is shown and the contents of the W and Status register. The values shown for PC and W are in hexadecimal. The status register is shown as a binary number, and additionally the three letters 'z', 'd' and 'c'. The letters correspond to the lowest three bits of the status register, which are used as the Zero, Decimal overflow and Carry flags. If the bit is '0', the letter is shown in lower case - the flag is not set. If the bit is '1', the flag is set, and the letter is shown in uppercase.

Individual registers can be examined by entering the register address in the Register box and pressing the '->' button or single stepping the simulator, at which point the content of that register is shown. A new value may be entered in the field and the register set to that value by clicking the 'Set' button. Both register number and contents are displayed in Hexadecimal.