Fast routing of custom macros

A computer based method of creating a flat placed layout for use in routing an integrated circuit (IC), the method comprising:

• creating a hierarchical schematic of the integrated circuit, the hierarchical schematic including high level descriptions of circuit components wherein each circuit component includes one or more cells of interest;
• creating a hierarchical, placed, non-routed layout from the hierarchical schematic;
• creating a flat layout from the hierarchical schematic, the flat layout including connectivity information between the one more cells of interest;
• for each cell of interest, traversing the hierarchical placed layout and accumulating relative placement information and back annotating the relative placement information to the connectivity information;
• and
• creating a routing diagram from a result of the back annotation.

A computer program product for creating a flat placed circuit diagram, the computer program product comprising:

• a storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for facilitating a method including:
• creating a hierarchical schematic of the integrated circuit, the hierarchical schematic including high level descriptions of circuit components wherein each circuit component includes one or more cells of interest;
• creating a placed, non-routed layout from the hierarchical schematic;
• creating a flat layout from the hierarchical schematic, the flat layout including connectivity information between the one more cells of interest;
• for each cell of interest, traversing the placed layout and accumulating relative placement information and back annotating the relative placement information to the connectivity information;
• and
• creating a routing diagram from a result of the back annotation.