Patent ID: 7890909

Claim:
A method for automatically composing a custom block of an integrated circuit (IC) design layout, wherein the custom block comprises one or more non-standard library cells, the method comprising: creating a placement control file including instructions for use by a custom block composition tool to place the one or more non-standard library cells into the custom block of an IC design layout; a computer executing program instructions that comprise a custom block composition tool which compose the custom block by: instantiating a leafcell for each non-standard library cell and each standard library cell included in a netlist of the custom block, wherein each leafcell comprises a layout view of each of the non-standard library cells and the standard library cells; accessing the placement control file and placing each leafcell in a row of the custom block according to the placement control file; pre-routing and tagging power, clock, and critical network signals within the custom block, wherein the tags specify the pre-routed signals are not modifiable by a router design tool; specifying information associated with one or more metal layers of the custom block; generating a router control file that includes the information used by a router design tool during remaining routing of the custom block; providing the pre-routed custom block, including the tags, to the router design tool such that the router design tool routes any remaining signals of the custom block.