Simulator Directives — Dot Commands

To run a simulation, not only must the circuit be defined, but also the type of analysis to be performed. There are seven different types of analyses: linearized small signal AC, DC sweep, noise, DC operating point, small signal DC transfer function, transient analysis, and transient frequency response analysis. Precisely one of these analyses must be specified when you run a simulation.

Whereas the circuit topology is typically schematically drafted, the commands are usually placed on the schematic as text. All such commands start with a period and are called "dot commands".

.AC — Perform an Small Signal AC Analysis Linearized About the DC Operating Point

.BACKANNO — Annotate the Subcircuit Pin Names on Port Currents

.DC — Perform a DC Source Sweep Analysis

.END — End of Netlist

.ENDS — End of Subcircuit Definition

.FOUR — Compute a Fourier Component

.FRA — Perform a Time-Domain Frequency Response Analysis

.FUNC — User Defined Functions

.GLOBAL — Declare Global Nodes

.IC — Set Initial Conditions

.INCLUDE — Include Another File

.KEEPNODE — Keep Nodes From Being Optimized Away