Analysis Options dialog box
The Analysis Options dialog box is opened when you click on the Options button in the Analysis section of the Cadence Virtuoso Interface main window. This dialog box allows you to access the run options for your analysis. The control fields are explained below.
Sonnet allows a user to run simulations on their own computer using a local copy of the analysis engine or to submit the job to an analysis engine running on another computer (Remote em). You can use settings in the Options dialog box to determine which processor runs the analysis. The Simulation Program area of the Options dialog box allows you to control this.
Auto-Detect Program: Selecting this option allows the software to determine the processor settings for Sonnet on your computer and submit the job to your default processing choice. If you wish to specify Local or Remote processing, clear this checkbox.
Local: Selecting this option runs your simulation on a locally installed copy of the analysis engine. Note that if a local copy is not available, this option is disabled.
Remote: Selecting this option runs your simulation on a remotely installed copy of the analysis engine, em. To configure a remote server, click on the Configure button to open the the Em Server List page in the Sonnet Administration dialog box in which you can configure a Remote em processor. For more information on configuring and using Remote em, please refer to the Remote em Computing manual.
Progress Bar: Select this checkbox if you wish to have a progress bar displayed during a Sonnet simulation.
This section of the Analysis Options dialog box allows you to control some advanced run options for your analysis engine EM simulation.
Compute Currents: Select the Compute Currents checkbox to compute current density data during your analysis. This run option outputs current density information for the entire circuit which can be viewed using Sonnet’s Current Density Viewer. Be aware that for an adaptive sweep, current density data is only calculated for discrete data points and this option is not available for a DC Point sweep.
For instructions on how to open the current density viewer, see Results ⇒ View Currents.
Q-Factor Accuracy: Selecting this option forces a higher accuracy for ABS convergence in Sonnet. This is done to increase the importance of the Q-factor as a criteria for the convergence of the ABS analysis. The result is higher accuracy from the ABS sweep, but this accuracy comes at the cost of requiring more discrete frequencies to be analyzed before conversion is reached. For a discussion of Adaptive Band Synthesis, see Adaptive Band Synthesis in the Sonnet User’s Guide.
Click on the Advanced button to open the Advanced Project Options dialog box.
The Subsectioning Options section of the Analysis Options dialog box allows you to exercise some control over how the subsectioning is done for your Sonnet analysis. The general rule is that the more subsections you use, the more accurate the answer, but at the cost of increasing processing time and required memory. These controls allow you to weight your analysis towards speed or accuracy.
Default Metal Fill Type: This field allows you to set the default fill type for metal polygons in the translated project. Choose from Staircase, Diagonal or Conformal. For more information on fill types in Sonnet, please see the Metal Properties dialog box.
Default Via Fill Type: This field allows you to set the default fill method for vias in your translated project. Choose from Ring, Vertices, Center, Full or Bar. For more information on via fill methods, please see the Via Properties dialog box.
Analysis Speed/Memory Control: The Analysis Control setting allows you to control the memory usage for an analysis by controlling the subsectioning of your circuit.
For a complete discussion of subsectioning please refer to Subsectioning in the Sonnet User’s Guide.
As mentioned above, the high memory settings produce a more accurate answer and usually increase processing time. Conversely, low memory settings run faster but do not yield as accurate an answer.
You control this by selecting a setting from the drop list. There are presently three settings, detailed below:
Click on the Advanced button to open the Advanced Subsectioning Options dialog box.
You are able to control how many of the circuit elements are translated when moving from the Cadence Virtuoso environment and creating a Sonnet project using the analysis engine.
There are three options available in the Translations Options section of the Analysis Options dialog box: Simplify Single Vias, Simplify Array Vias and Identify Bar Vias.
Simplify Single Vias: This option places a bounding box on vias being imported and creates a rectangular via the size of the bounding box in place of the imported via.
Simplify Via Arrays: This option locates via arrays and performs simplification to create one equivalent via in Sonnet to represent the via array in order to increase analysis efficiency by reducing the memory and processing requirements for the circuit. This feature automatically performs this simplification during the translation process using controls set by the user. For a detailed discussion of Via Array Simplification, please see Via Simplification. The options which control simplification are available in the advanced translation options.
Identify Bar Vias: This option is enabled when the Simplify Via Arrays option is enabled. This option will identify bar vias when the L/W ratio requirement is met. Each via identified as a bar via will have its via fill type set to Bar via fill type during translation. Enter the desired minimum length to width ratio a via polygon must possess to be considered a bar via. The default value is 2.5. For a detailed discussion of Bar Via Simplification, please see please see Via Simplification.
Click on the Advanced button to open the Advanced Translation Options dialog box.
You may specify an adaptive band synthesis (ABS) sweep for your analysis in the Add Frequency Type dialog box. Click on the Advanced button to open the Advanced ABS Options dialog box.
Clicking on the Summary button in the Analysis Options dialog box opens the Summary of Options window. This window provides a complete list of all selected options.