Simulation does not Run

What should I do when I try to run a simulation and nothing happens?

Solution

When you attempt to run a simulation and nothing happens (the Simulation Control dialog box does not appear, for example), it typically means that a problem occurred either when you netlisted your design, or when Hyperlynx AMS compiled the models. Information on netlisting or compilation displays in the Log window. Scroll to the top of the Log window and look for the first occurrence of any error messages. Error messages generally include or direct you to a solution.

No Waveform Analyzer after Running a Simulation

What should I do when the Waveform Analyzer does not open after running a simulation?

Solution

When the Waveform Analyzer does not appear after running a simulation, it typically means that it encountered a simulation problem. Any simulation problems display as error messages in the Log window, which generally include or direct you to a solution. Scroll to the top of the Log window, and look for the first occurrence of any error messages.

No Waveforms in Waveform Analyzer

What should I do when the Waveform Analyzer opens after running a simulation, but opens without any waveforms, or opens with waveforms that cannot be plotted?

Solution

When the Waveform Analyzer opens with no waveforms displayed after running a simulation, it typically means that Hyperlynx AMS encountered a simulation problem or you may not have specified waveforms under the Results tab in the Simulation Control dialog box. Error messages for simulation problems display in the Log window. Scroll to the top of the Log window, and look for the first occurrence of any error messages.

Symbols Enclosed in Pink Boxes

When I open my schematic, some of the symbols are enclosed in boxes. What does this mean and what do I do about it?

Solution

A pink (sometimes blue) border enclosing a symbol in a schematic indicates that the symbol properties have been modified since the last time the schematic was opened. To remove the borders, right-click in the schematic (but not on a symbol), and choose the Component Update > Apply All Symbol Updates popup menu item.

Waveforms Not Available in Waveform Analyzer

How do I display other design waveforms that are not available in the Waveform Analyzer?

Solution

By default, all of a design’s top-level node waveforms (for example, voltages, pressures, velocities) are available for viewing after a simulation. To display any other waveforms (for example, current, flow, torque), or all possible waveforms, click the Results tab in the Simulation Control dialog box and select any waveforms of interest (you will need to re-run the simulation after selecting waveforms in the Results tab).

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No Value Specified for Parameter Error Message

I have an error message that says, “No value specified for parameter.” What does this mean and what can I do about it?

Solution

To simulate these models, supply a value as follows:

1. Right-click on the symbol in question and choose the Edit Model Properties popup menu item. The error message identifies which symbol/model does not have a parameter value.
2. In the resulting dialog box, click the Parameters tab.
3. Type a value for the parameter (all parameters must either have a default or user-supplied value).
4. Click OK

 

Display Parameters for Symbols Using Standard SI Prefixes

How do I display parameters for the symbols using standard SI prefixes (for example, “1k” rather than “1.0e3”)?

Solution

Hyperlynx AMS displays VHDL-AMS model parameter values in the formats supported by the language, which do not include SI prefixes by default. For passive components (such as R, L, and C), use SPICE models from the SPICE Primitive library to display parameter values in SI formats.

No Node Found in Circuit Error

I am getting a “No node ‘0’ found in circuit” error. What does this mean and what can I do about it?

Solution

When a ground symbol (or electrical_ref, rotational_ref, and so on) is attached to a net on a schematic, that net will become a ground net (and will netlist to the value "0"). Under rare conditions (for example, if this net is renamed manually or in some other manner), the design cannot simulate because it has no reference to ground. If this error occurs, delete all the nets that attach to the ground, then re-add the nets and re-attach the ground symbol. When finished, the net is named “electrical_ref” if it is attached to electrical ground.

PINORDER Error

I am getting a PINORDER error. What does this mean and what can I do about it?

Solution

Every Hyperlynx AMS symbol must have a PINORDER attribute. If you are creating or modifying symbol pins, these changes must also be made to the PINORDER attribute (the Symbol Editor does not do this automatically). For example, if you have a symbol with pins 1, 2, and 3, and you change them to gate, drain, and source, then you must also change the PINORDER property as follows: FROM: PINORDER = 1 2 3; TO: PINORDER = gate drain source.

Physical Location of Design

Where is my design physically located?

Solution

You can navigate to your current design or project from within Hyperlynx AMS. To do so:

1. Click the Simulation tab in the Navigator pane.
2. Right-click the Project Contents folder and choose the Explore Project Folder popup menu item.

The folder that contains your current project opens in Windows Explorer.

Set Initial Conditions on Circuit Nodes

How do I set initial conditions on circuit nodes?

Solution

Use either of the two most commonly used initial condition commands: .ic or .nodeset.

• .ic — Initial Condition command
  
  The .ic command specifies node voltages (or any “across value” variable) for use for the duration of a DC (operating point) analysis. After the DC analysis, Hyperlynx AMS uses the voltages specified by the .ic command as the starting values for a transient analysis.
  For example, use this command to set node input to 2 and node osc_out to 3.3 as follows:
  1. Open the Simulation Control dialog box by choosing the Simulation  AMS> Simulate 
  2. Click the Advanced tab.
  3. In the Additional Commands field, type the following:
     • .ic v(input)=2 v(osc_out)=3.3
     • or this: .ic input=2 osc_out=3.3  
  4. OK

Tip: The UIC (Use Initial Conditions) option works in conjunction with the .ic command to prevent a DC (operating point) analysis before running the transient analysis. When using UIC, Hyperlynx AMS sets the node values specified with the .ic command; the simulator calculates all other node values without first finding a DC solution. You can enable or disable UIC in the Simulations tab of the Simulation Control dialog box (click Setup in the Time-Domain Analysis area)

• .nodeset — Set Node Value command
  
  The .nodeset command specifies node voltages or other “across values” for Hyperlynx AMS to use when calculating the DC solution. Hyperlynx AMS uses the specified values to find an initial DC solution, after which time it computes a second and final DC solution without the .nodeset command.
  1. Open the Simulation Control dialog box by choosing the Simulation AMS > Simulate menu item
  2. Click the Advanced tab.
  3. In the Additional Commands field, type the following:
     • .nodeset v(input)=2 v(osc_out)=3.3
     • or this: .nodeset input=2 osc_out=3.3
  4. OK

Tip: To set initial conditions for current or other “through values,” refer to the various symbols/models themselves for an initial condition parameter that can be set. For example, the default VHDL-AMS inductor model has an I_IC parameter that sets an initial current.
For more detailed information on using these and related commands, use the Hyperlynx AMS InfoHub (Help > Open AMS Documentation). From within InfoHub, search for: Setting Initial Conditions

Specify Advanced Simulation Options

How do I specify advanced simulation options?

Solution

In Hyperlynx AMS, you can specify advanced simulation options in the Additional Commands box on the Advanced tab of the Simulation Control dialog box. You can invoke these options using the .option command.

For example, to change from the default integration algorithm, TRAP (for Trapezoidal), to BE (Backward Euler), type the following:
                            .option be

You can find a complete list of the .options available with Hyperlynx AMS in the InfoHub ( AMS Simulation > AMS Documentation). 

Search for the .option command and select .OPTION Command from the resulting topic list to get a complete listing of Hyperlynx AMS .option commands.

 

Note: You can directly specify advanced options as well as initial conditions in command files. All simulation options that you specify in the Simulation Control dialog write to the appropriate command file, which you then edit manually. For a given simulation, Hyperlynx AMS automatically places a link to this file in the log window.