Pin Permutation
Layout XL lets you exchange the connectivity or net connections of the pins of a component. This operation is called pin permutation. The pins to be permuted must belong to different nets and must first be defined as permutable terminals. If one of the pins to be permuted is on an instance contained in any type of group (including a synchronous clone), the other pin must be on an instance in the same group.
When a device has must-connected terminals connected to different nets at the current level, these nets, by definition, must be connected further up the hierarchy. For the purposes of pin permutation, such nets are considered equivalent.
In the device below, nets terminals S, S2, and S3 are defined in a must-connect relationship. Terminals D and D2 are in a separate must-connect relationship. All the terminals are connected to different nets at the current level.
The following permuteRule is specified for the device.
p(S2 D)
Any net connectivity changes made to S2 will also be applied to all its other must-connected terminals, for example; S, S3. The same applies for D and D2. The permute model is as illustrated below.
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