.nodeset

.nodeset v(node1) = val1 [v(node2) = val2] ... [v(noden) = valn] subckt=subckt_name depth=depth_val

Description

Specifies the nodesets for the node. The Spectre FX simulator forces the node voltage to the specified value at the first operating point iteration and then the solver calculates the node voltage used at time=0. A node name can be hierarchical and can contain wildcards. The statement can be embedded within the scope of a subcircuit. In this case, the initial guess is assigned to the nodes local to the subcircuit. If a conflict occurs between an embedded nodeset and a hierarchical nodeset, the embedded one is considered.

The .nodeset statement can be used to enhance convergence in the DC analysis. If the node value is set close to the actual DC operating point, convergence can be improved.

Arguments

Example

.nodeset v(n1) = 0.5 v(n2) = 1.5

In the above example, the initial starting point for the operating point calculation is 0.5 V for n1 and 1.5 V for n2. The final operating point for both nodes may be slightly different because .nodeset is used only at the first iteration.