1.2.3 User Interface Feature Tour

The Command (F11) Window

Every schematic and schematic component file has a command, or F11 window, which can be shown or hidden by pressing the F11 key. During the netlist process, the contents of the F11 window are placed in the netlist before any content from that schematic level is added. The F11 window is a good place to enter additional netlist content, including subcircuit models, graphing statements, and variable statements. The F11 window also stores the analysis directives you enter in the Simulator > Choose Analysis... dialog.

The F11 window of the schematic is shown below:

.SIMULATOR SIMPLIS
.AC DEC 100 1k 400k
.PRINT
+ ALL
.OPTIONS
+ PSP_NPT=10001
+ POP_ITRMAX=20
+ POP_OUTPUT_CYCLES=5
+ SNAPSHOT_INTVL=0
+ SNAPSHOT_NPT=11
+ MIN_AVG_TOPOLOGY_DUR=1a
+ AVG_TOPOLOGY_DUR_MEASUREMENT_WINDOW=128
.POP
+ TRIG_GATE={TRIG_GATE}
+ TRIG_COND=0_TO_1
+ MAX_PERIOD=2.2u
+ CONVERGENCE=1p
+ CYCLES_BEFORE_LAUNCH=5
+ TD_RUN_AFTER_POP_FAILS=-1
.TRAN 70u 0

.SIMULATOR DEFAULT
.VAR ILOAD = 5
.VAR VO    = 1.2
.VAR RLOAD = {VO/ILOAD}
 

The first section of the F11 window contains the analysis directives. When you execute the schematic menu Simulator > Choose Analysis... , the values you enter are saved to the top of the F11 window. Because the dialog will manipulate the F11 window content, any user-defined content should be placed below the .SIMULATOR DEFAULT statement. The user entries in the F11 window are:

.VAR ILOAD = 5
.VAR VO    = 1.2
.VAR RLOAD = {VO/ILOAD}

These variable statements define the load resistance value. The actual load resistor symbol uses a value which is set to : {RLOAD}. Whenever a variable or set of variables and constants is placed inside the curly brackets {}, this tells the simulator to evaluate the expression contained between them. In this case, the simulator will replace the {RLOAD} expression with the value of the VO variable divied by the ILOAD variable prior to the simulation.

Finding Net Names on the Schematic

Hover your mouse over any wire on the schematic and the net name is displayed on the bottom bar of the schematic window.

While you are here, there is a wealth of information on the bottom bar of the schematic. From left to right:

• Select: The current command ready to execute - that is the selection of symbols or wires.
• X 1: The current zoom level.
• Modified: The schematic has been modified since it was opened.
• NET=12: The net name nearest the cursor.
• SIMPLIS: The simulator mode for the current schematic.

Hierarchical Schematic Component Files

There are two types of schematic files used in SIMetrix/SIMPLIS.

• A Schematic file has no symbol associated with it and is the "top level", or parent, schematic. This schematic has all the analysis information contained in the F11 window. Some users might think of this type of schematic as a "test bench." Schematic files have the extension .sxsch or .wxsch.
• A Schematic Component file includes both a symbol and a schematic containing hierarchical ports which match the pins on the symbol. The Schematic Component file is a self contained module with space for both the electrical model information in schematic form, and the symbol which is required to connect the model to a parent schematic. Schematic Component files have the extension .sxcmp.

The 1.2_SIMPLIS_tutorial_buck_converter.sxsch schematic contains one model implemented with a Schematic Component file, the compensator U3. To view the schematic for the compensator,

1. Select U3.
   Result: The symbol turns from red to blue, indicating that it is selected.
   
2. Press the keyboard shortcut key combination Ctrl+E, or use the schematic menu Hierarchy > Descend Into .
   Result: The schematic view of the 3p2zcompensator Schematic Component opens.
   
3. Press the Home key.
   Result: the schematic zooms to fit all symbols and wires on the 3p2zcompensator.sxcmp schematic.
   
4. To ascend a level to the parent of U3, Press Ctrl+U, or use the schematic menu Hierarchy > Ascend .
   Result: The parent schematic tab 1.2_SIMPLIS_tutorial_buck_converter.sxsch comes into focus.

Schematic component files are covered in depth in the 4.2 What is a Schematic Component File? topic.

Hierarchical Symbols

There are several ways to edit the symbol portion of a Schematic Component file, depending on which schematic you have open. If you are viewing the symbol as placed on a parent schematic:

1. From the parent schematic, select U3.
2. Right click to bring up the context menu and select Edit Symbol:
   Note: The keyboard shortcut Shift+S will execute the same menu item.

If you are viewing the schematic portion of the schematic component,

1. From the 3p2zcompensator.sxcmp schematic view, select Hierarchy > Open/Create Symbol for Schematic...
   Note: The keyboard shortcut S will execute the same menu item.

Both these methods will open the symbol editor to the symbol contained in the 3p2zcompensator.sxcmp file:

Saving Window Size and Position

The program automatically remembers the size and position of each pop-up dialog every time you close the dialog. The main window also remembers the size and location of the system windows when the program is started.