Method and apparatus for considering diagonal wiring in placement

A method of placing circuit modules in an integrated circuit (“IC”) layout, wherein said IC layout includes a net having a plurality of circuit elements, the method comprising:

• a) constructing a connection graph that connects the circuit elements of the net, said connection graph having edges, wherein at least one of the edges is at least partially diagonal;
• b) identifying a placement metric based on the connection graph;
• and
• c) using the placement metric to identify a placement of the circuit modules.

For an electronic design automation application, a method of placing circuit modules in an integrated circuit (“IC”) layout, wherein said IC layout includes a plurality of nets each of which includes a plurality of circuit elements in the IC layout, wherein the EDA application includes a wiring model that defines different types of interconnect lines for connecting the circuit elements of the nets, said wiring model having diagonal lines, the method comprising:

• a) for each particular net, defining a minimum spanning tree that models the topology of interconnect lines for connecting the circuit elements of the particular net, said minimum spanning trees having edges, wherein at least one of the edges of at least one of the minimum spanning trees is at least partially diagonal;
• b) calculating the length of the edges of the minimum spanning trees;
• c) combining the length calculations to obtain an estimate of the total interconnect-line length needed for connecting the circuit elements of the nets during a routing operation;
• and
• d) using the combined length calculations to identify a placement of the circuit modules.

For an electronic design automation application, a method of placing circuit modules in an integrated circuit (“IC”) layout, wherein said IC layout includes a plurality of nets each of which includes a plurality of circuit elements in the IC layout, wherein the EDA application includes a wiring model that defines different types of interconnect lines for connecting the circuit elements of the nets, said wiring model having diagonal lines, the method comprising:

• a) for each particular net, defining a Steiner tree that models the topology of interconnect lines for connecting the circuit elements of the particular net, said Steiner tree having edges, wherein at least one of the edges of at least one of the Steiner trees is at least partially diagonal;
• b) calculating the length of the Steiner trees;
• c) combining the length calculations to obtain an estimate of the total interconnect-line length needed for connecting the circuit elements of the nets during a routing operation;
• and
• d) using the combined length calculations to identify a placement of the circuit modules.

A method of placing circuit modules in an integrated circuit (“IC”) layout, wherein said IC layout includes a set of circuit elements, the method comprising:

• a) identifying a connection graph that connects the set of circuit elements, wherein said connection graph has a plurality of edges, wherein at least two of the edges are neither parallel nor orthogonal to each other;
• b) identifying a placement metric based on the connection graph;
• and
• c) using the placement metric to identify a placement of the circuit modules.