eldo_user

Specifying Simulation Output
Plot and Print Quantities
Tip
See “.EXTRACT” in the Eldo Reference Manual.
Plot and Print Quantities
Plotting and printing commands can be specified as extract commands. The plot and print
quantities are generic, so the same syntax applies when specifying these in .EXTRACT
statements. For example the following command plots the drain current of a MOSFET model:
.plot DC ID(XA2.M1)
This can also be specified as an extract as follows:
.extract DC ID(XA2.M1)
LVnn (Element) syntax is used to obtain user-input parameters, the following example returns
the effective channel width:
.extract DC LV2(M1)
LXnn (Element) is used to obtain computed values such as charges, capacitances and
derivatives, the following example returns the Drain-Source voltage (VDS):
.extract DC LX3(M1)
When extraction statements are combined with parameter sweeping statements (for example
.STEP) Eldo automatically creates waveforms showing the extraction results versus the swept
parameter. For example, you may extract the width of an output pulse from a transient
simulation and sweep the power supply level, in which case Eldo will automatically create a
waveform showing the width of the pulse versus the power supply level. Similarly, if
extractions and .ALTER statements are combined, Eldo will automatically create waveforms
showing the extraction results versus the index of the .ALTER runs. In this case, the X axis will
contain 1, 2, 3, and so on. The initial display in the viewer can also be prepared using .PLOT
commands (see the .PLOT EXTRACT... description). For example:
.EXTRACT TRAN label=VMAX MAX(V(out))
.PARAM powersupply=1.2
VDD VDD 0 'powersupply'
.STEP PARAM powersupply list 1.2V 1.3V 1.4V 1.6 2V
.PLOT EXTRACT meas(VMAX) ! this will create a waveform
* showing VMAX(powersupply)
By default, using the .wdb format, the .EXTRACT waveforms are saved inside the EXT folder
in the main .wdb file. Specify option EXTFILE to generate a .ext.wdb file with only the
extraction results. The .ext.wdb file will not always be created as it depends on the type of
simulation and the specification of the .EXTRACT command.
Eldo® User's Manual, 15.3 323