Product Documentation
Virtuoso ADE SKILL Reference
Product Version IC23.1, November 2023

ALIAS

ALIAS( 
t_globalVar 
) 
=> t_globalVarValue / nil

Description

Can be used in two scenarios- to give alias or alternate names to long net names or instance name paths, and to return the first value of a waveform result, for non-swept variables.

For the second purpose, ALIAS provides a wrapper around the VAR function to output a scalar value by returning the first Y value from the VAR waveform. Therefore, you can replace VAR with ALIAS where VAR returns a waveform but you need a scalar value for an output or expression. ALIAS returns the first Y value of the waveform returned by VAR.

You cannot use ALIAS function in the following cases:

Arguments

t_globalVar

Name of the global variable.

Value Returned

t_globalVarValue

Value of the global variable.

nil

Unsuccessful operation.

Examples

The following example demonstrates how to use a net/terminal name with an alias name:

mynet =”/I0/I1/M1/M2/M3/net2”
db(vh('hbac ALIAS("mynet") '((0 -1))))

Functions such as VT, VF, or VH expect a net/terminal name, and perform unsuccessfully with VAR. Instead, it is recommended to use ALIAS with such functions.

The following example demonstrates when to use ALIAS within a calculator function to provide a single scalar value for outputs that return a waveform:

X_Freq = 1M 
value(db(vh('hbac "/X4" '((0 -1))))  ALIAS("X_Freq"))
The value function expects a scalar value in the second argument. If we use VAR("X_Freq"), it returns a scalar value when evaluating at the leaf level, but a waveform at the root level, where all the values will be 1M. Therefore, it is recommended to use ALIAS because it returns a scalar at the leaf level, and the first value from the waveform, when evaluating at the root level.

When to avoid using ALIAS?

In example2 shown above, if the X_Freq variable is swept with three different values, as shown below, ALIAS returns the value, 1M: 

X_Freq = 1M 2M 3M
value(db(vh('hbac "/X4" '((0 -1))))  ALIAS("X_Freq"))

Here, using ALIAS("X_Freq")would only provide the first value from the swept variable, which would be incorrect.

Therefore, it is strongly recommended not to use ALIAS with sweep variables, as it returns incorrect result values.


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