Syntax: Xxxx n1 n2 n3... <subckt name> [<parameter>=<expression>]
Subcircuits allow circuitry to be defined and stored in a library for later retrieval by name. Below is an example of defining and calling a voltage divider and invoking it in a circuit.
*
* This calls the circuit
X1 in out 0 divider top=9K bot=1K
V1 in 0 pulse(0 1 0 .5m .5m 0 1m)
*
* This is the subcircuit definition
.subckt divider A B C
R1 A B {top}
R2 B C {bot}
.ends divider
*
.tran 3m
.end