Analog Systems in VLSI, Fall 2004: Using the calculator in cadence
Select Tools -> Calculator in the Analog Artist window to start
the calculator. The operations available in the calculator can be
performed on waveforms or electrical quantities in the circuit.
Run the simulation.
Calculator
Measuring the group delay(after an ac simulation): Click on vf
in the calculator(see below for other choices). You can select the
required nodes in the circuit which will be stored in the calculator's
stack(Activate the Display Stack button to display the
stack). Hit ESC when done. You can circulate through the
stack's contents using up and dwn buttons on the
calculator. Get the desired variable into the buffer:
e.g. VF("/out"). Select Special Functions ->
groupDelay. The buffer now displays
groupDelay(VF("/out")). Click on plot in the calculator
window to plot it in the currently active window.
Calculator with groupDelay(VF("/out")) displayed
Other quantities can be selected(see below) and other operations can
be similarly performed.
vf: voltage from an ac analysis
if: current from an ac analysis
vt: voltage from an transient analysis
it: current from an transient analysis
vdc: voltage from an operating point analysis
idc: current from an operating point analysis
vdc: voltage from an dc sweep analysis
idc: current from an dc sweep analysis
You can click on the Help button on the calculator for
additional help.
