eldo_user

Subcircuit Definitions and Calls
Eldo Netlist Setup
Subcircuit Definitions and Calls
A subcircuit consists of a group of elements. To define a subcircuit within a circuit description
file, begin the subcircuit block with a .SUBCKT command and terminate it with the .ENDS
command.
Use the Xxx statement to instantiate a subcircuit previously defined using a .SUBCKT
command. All components and nodes used in the subcircuit definition are known only locally,
unless they have been globally defined via .GLOBAL or .PARAM commands. .MODEL
specifications inside the subcircuit are also known only locally. There is no limit to the size or
complexity of the subcircuit.
Tip
See “.SUBCKT,” “.ENDS” and “Subcircuit Instance” in the Eldo Reference Manual.
Related Topics
Netlist Structure
Working With Subcircuits and Device Libraries
Element and Source Definitions
The circuit connectivity (netlist) is described in the netlist file by element statements of devices
and sources.
Element statements provide:
• element name
• nodes the element is connected to
• parameter values
The first letter of the element name is a key letter indicating the element type, for example:
R for resistor, M for MOSFET, V for voltage source, and X for subcircuit instance.
Component Names
Component names start with the component reserved characters and continue with an arbitrary
sequence of alphanumeric characters, including %, $, #, _. Component names cannot be broken
at the end of a line.
Node Name Conventions
Node names may contain an arbitrary sequence of alphanumeric characters and some nonalphanumeric
characters including: !, $, #, _, [], , :, \, /, |, +, -, *, %.
Eldo® User's Manual, 15.3 99