Working With Pin Connectivity Models

The pin connectivity model for a design defines the connectivity pattern to be followed during routing. The model specifies how to connect nets to terminals, terminals to pins, and pins to figures.

Supported Pin Connectivity Models

Layout XL supports the following pin connectivity models:

• Strong-connect model: In the strong-connect model, a single connection point on a highly conductive metal is used to provide the required connectivity. You create a strong-connect group of the required pin figures.
• Weak-connect model: A weak-connect model is applicable in situations where a router must connect to a single pin, but the terminal has more than one pin, each of which has one or more shapes or pin figures. In this model, the router can connect to any shape of any pin, but it cannot use the pin as a feedthrough pin.
  This model is useful when two pins are connected using resistive wires, such as local interconnect.
• Must-connect-model: In the must-connect model, the drain, source, and gates of a MOS device are isolated. External, individual connections are made to these terminals.
• Must-connect-all-pins model: The must-connect-all-pins model is applicable to terminals that have more than one pin. This model applies the following settings:
  • Routers, such as Virtuoso Space-based Router (VSR), connect to all pins of the selected terminal.
  • The connectivity extractor flags all unconnected pins of the selected terminal.
  • Tools such as the wire editor display flight lines to all pins of the selected terminal.

Related Topics

Setting a Pin Connectivity Model

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