Abstract: Soft pin locations in a hybrid paradigm are optimized according to circuit density centers of circuit components coupled to the soft pins. As a result, the soft pins are located closer to components with heavier loads and further from components with lighter loads. Circuit density centers are determined by summing coordinates weighted by circuit loads, including capacitance and resistance, and dividing the summed weighted coordinates by a sum of the weights. To avoid blockage, optimized soft pin locations can be moved to soft block boundaries relative to the optimized locations.

Abstract: A hierarchical circuit design is divided into independent components which can be processed independently of one another to simultaneously achieve the advantages of both hierarchical and flat paradigms. Blocks of the circuit design are flattened sufficiently to place and route global networks through the blocks. The flattened blocks of the circuit design are de-coupled to form independent blocks. In de-coupling the blocks, pins are added at intersections of the global networks with boundaries of the blocks. The global networks are divided into wire fragments between the pins and components of the flattened circuit design in generally the same place previously occupied by the global networks. Wire fragments inside a particular block of the circuit design are added to the block. Wire fragments outside all blocks are fixed as components of the circuit design. The blocks are therefore de-coupled at the pin positions along the block boundaries.