US Patent 7386821 Primitive cell method for front end physical design

A method for forming an integrated circuit (280) comprises accessing (282) a library of primitive cells and edge codes in the formation of an integrated circuit layout. At least one edge code of at least one previously placed primitive cell (284) of the integrated circuit layout is used. A primitive cell is selected (286) from the library that is compatible with the at least one previously placed primitive cell and the selected primitive cell is placed into the integrated circuit layout adjacent the at least one previously placed primitive cell. The integrated circuit is manufactured (290) using the integrated circuit layout.