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Analyzing Simulation Results<br />

Performance Diagnostics<br />

Node X1.Q1_C<br />

Slope = 5.5538E+01V/ns<br />

Time = 3.4168E+00ns<br />

Node X1.3<br />

Slope = 5.4934E+01V/ns<br />

Time = 3.4168E+00ns<br />

Node X1.2<br />

Slope = 5.3028E+01V/ns<br />

Time = 9.2519E-01ns<br />

Node X1.Q1_B<br />

Slope = 5.3025E+01V/ns<br />

Time = 9.2519E-01ns<br />

Node 1<br />

Slope = 5.1499E+01V/ns<br />

Time = 2.0100E+00ns<br />

...<br />

CPU Time Evaluating Device Types<br />

The performance diagnostics records the percentage of CPU time spent evaluating the different<br />

type of devices. This distribution is reported per Verilog-A model, and per type of MOS, BJT,<br />

Diode, and JFET model. Example output of simulation time taken by the device model<br />

evaluation:<br />

Device Type/Model Name | nb of instances | Elapsed CPU Time | 1st %* | 2nd %**<br />

-------------------------------------------------------------------------------------------<br />

Linear Elements | 180269 | 11s | | 39.04%<br />

-------------------------------------------------------------------------------------------<br />

Diodes | 1458 | 2s | | 7.14%<br />

BERKDIO | 1458 | 2s | 100.00% | 7.14%<br />

-------------------------------------------------------------------------------------------<br />

MOSFET | 18353 | 16s | | 53.65%<br />

BSIM3V3 | 18353 | 16s | 100.00% | 53.65%<br />

-------------------------------------------------------------------------------------------<br />

• The “1st %” column is the percentage of time over the total load time for that type of<br />

device (MOSFET for example).<br />

• The “2nd %” column is the percentage of time over the total load time for all devices<br />

included.<br />

• All types taking less than 1s of elapsed CPU load time are ignored.<br />

Performance Diagnostic Outputs<br />

By default, for Questa ADMS and Eldo Classic/Premier, the reports are printed in the .chi file.<br />

If the -stat flag has been set on the command line then the reports are printed in the statistics file<br />

(.stat). Table 9-2 below summarizes the various ways to activate the performance diagnostics in<br />

Eldo and Questa ADMS. In the table, steps is the step statistics, slope is the steepest variation<br />

detection, and devcpu is the CPU time measurement in device evaluation.<br />

Eldo® User's Manual, 15.3 383

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