Measure Simulation Results
Extract metrics from completed simulations via virtuoso sim measure.
Usage
virtuoso sim measure --analysis <TYPE> --expr '<EXPRESSION>' [--expr '<EXPR2>'] --format json
DC operating point measurements
# Voltage at a node
virtuoso sim measure --analysis dcOp --expr 'value(VDC("/net1"))' --format json
# Drain current
virtuoso sim measure --analysis dcOp --expr 'value(IDC("/NM0/D"))' --format json
# Operating point parameter (gm, gds, vth, etc.)
virtuoso sim measure --analysis dcOp --expr 'value(getData("/NM0:gm" ?result "dcOpInfo"))' --format json
virtuoso sim measure --analysis dcOp --expr 'value(getData("/NM0:ids" ?result "dcOpInfo"))' --format json
virtuoso sim measure --analysis dcOp --expr 'value(getData("/NM0:vth" ?result "dcOpInfo"))' --format json
# Multiple measurements at once
virtuoso sim measure --analysis dcOp \
--expr 'value(VDC("/net1"))' \
--expr 'value(IDC("/NM0/D"))' \
--expr 'value(getData("/NM0:gm" ?result "dcOpInfo"))' \
--format json
Transient measurements
# Peak voltage
virtuoso sim measure --analysis tran --expr 'ymax(VT("/OUT"))' --format json
# Minimum voltage
virtuoso sim measure --analysis tran --expr 'ymin(VT("/OUT"))' --format json
# Crossing time (settling)
virtuoso sim measure --analysis tran --expr 'cross(VT("/OUT") 0.6 1 "rising")' --format json
# Value at specific time
virtuoso sim measure --analysis tran --expr 'value(VT("/OUT") 10e-6)' --format json
AC measurements
# Gain at DC
virtuoso sim measure --analysis ac --expr 'value(dB20(VF("/OUT")) 1)' --format json
# Unity-gain bandwidth
virtuoso sim measure --analysis ac --expr 'cross(dB20(VF("/OUT")) 0 1 "falling")' --format json
# Phase margin
virtuoso sim measure --analysis ac --expr 'value(phase(VF("/OUT")) cross(dB20(VF("/OUT")) 0 1 "falling"))' --format json
Available signal accessors
| Function |
Domain |
Description |
VDC("/node") |
dc |
DC voltage |
IDC("/inst/term") |
dc |
DC current |
VT("/node") |
tran |
Transient voltage |
IT("/inst/term") |
tran |
Transient current |
VF("/node") |
ac |
AC voltage (complex) |
IF("/inst/term") |
ac |
AC current (complex) |
getData("/inst:param" ?result "dcOpInfo") |
dcOp |
Operating point param |
Waveform math functions
| Function |
Description |
ymax(wave) |
Maximum value |
ymin(wave) |
Minimum value |
value(wave time) |
Value at time/freq |
cross(wave val n dir) |
Time when wave crosses val |
dB20(wave) |
20*log10(magnitude) |
phase(wave) |
Phase in degrees |
bandwidth(wave level) |
-3dB bandwidth |
integ(wave) |
Integral over sweep range |
rms(wave) |
RMS value |
average(wave) |
Average value |
delay(wave1 val1 edge1 wave2 val2 edge2 n) |
Propagation delay |
slewRate(wave pct1 pct2 dir) |
Slew rate |
settlingTime(wave final tol) |
Settling time |
Noise measurements
# Run noise analysis first
virtuoso sim run --analysis noise --start 10 --stop 100e3 --dec 20 --timeout 120
# Spot noise at 1kHz
virtuoso sim measure --analysis noise \
--expr 'value(getData("/OUT" ?result "noise") 1e3)'
# Integrated noise (10Hz-100kHz)
virtuoso sim measure --analysis noise \
--expr 'integ(getData("/OUT" ?result "noise") 10 100e3)'
Common amplifier measurements (complete recipe)
# === DC operating point ===
virtuoso sim run --analysis dc --param saveOppoint=t
virtuoso sim measure --analysis dcOp \
--expr 'value(VDC("/OUT"))' \
--expr 'value(IDC("/M1/D"))'
# === AC: gain, GBW, phase margin ===
virtuoso sim run --analysis ac --start 1 --stop 10e9 --dec 20
DC_GAIN=$(virtuoso sim measure --analysis ac --expr 'dB20(value(VF("/OUT") 1))' --format json | jq -r '.measures[0].value')
UGB=$(virtuoso sim measure --analysis ac --expr 'cross(dB20(VF("/OUT")) 0 1 "falling")' --format json | jq -r '.measures[0].value')
PM=$(virtuoso sim measure --analysis ac --expr 'value(phase(VF("/OUT")) cross(dB20(VF("/OUT")) 0 1 "falling")) + 180' --format json | jq -r '.measures[0].value')
echo "Gain=${DC_GAIN}dB GBW=${UGB}Hz PM=${PM}°"
# === Transient: slew rate, settling ===
virtuoso sim run --analysis tran --stop 20u
virtuoso sim measure --analysis tran \
--expr 'slewRate(VT("/OUT") 10 90 "rising")' \
--expr 'slewRate(VT("/OUT") 90 10 "falling")'
deanyou