• Analog Custom Design & Analysis Examples

    Analog Custom Design & Analysis Examples

002 : Guardian LVS Supported SPICE Elements, Parameters and Commands

Minimum Required Version: Guardian LVS 4.8.36.R

Guardian LVS can process specific SPICE elements, such as independent voltage/current sources, voltage/current-controlled switches and so on. They are ignored during the normal LVS process, but they can be compared between a pair of netlists, in order to verify if the converted schematic data is equivalent to the original one.

A check box Process specific SPICE elements is provided in the General page in the Project Settings dialog. It compares those specific SPICE elements as well as the normal device instances. The result of the comparison is reported in the log file and unmatched node reports.

If some independent voltage sources are included in the netlist, the parameter comparison should be executed for more accuracy. The parameter of independent voltage sources includes transient analysis source specifications, such as pulse, sin, and cos. To check those parameters, another option, Match transient source parameters, should be turned on. Any discrepancies are reported in the parameter error file.

See the example of the log file with specific SPICE elements in App_lvs1.log.

The actual steps of the operation to check the command behaviors are as follows:

1) Start Guardian LVS in the GUI mode.

2) Select Setup->Project Settings command to show the Project Setting dialog (see Figure 1 ).

3) Click the Reset button in the Project Settings dialog.

4) Turn on the Input Files check box in the General page, and set the following netlists as #1 and #2 netlists:

#1 : App_lvs1.net (Created from the schematic as shown in Figure 2 )

#2 : App_lvs2.net (Created from the schematic as shown in Figure 3 )

5) Click the OK button in the Project Settings dialog.

6) Select Action->Run Lvs from the Guardian LVS menu bar. The netlist comparison will be executed, and Guardian LVS will report that those netlist are EQUIVALENT (see Figure 4 ).

In the log file, no specific SPICE elements such as V or SW will be reported, because they are ignored in the normal LVS process.

7) Select the Setup->Project Settings command again, and turn on the Process specific SPICE elements checkbox in the General page (see Figure 5 ).

8) Run Lvs again.

Guardian LVS will still report that those netlist are EQUIVALENT , but the specific SPICE elements will be compared and reported in the log file (see Figure 6 ).

9) Select the Setup->Project Settings command again, and open the Models page.

10) Select Independent Source->Voltage , and turn on the check boxes Match parameters and also Match transient source parameters (see Figure 7 ).

11) Run Lvs again.

Guardian LVS will still report that those netlist are topologically EQUIVALENT , but some parameter errors are detected (see Figure 8 ).

The details of discrepancies will be reported in the parameter error file (see Figure 9 ).

Input Files
Graphics
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