Integrated circuit hierarchical design tool apparatus and method of hierarchically designing an integrated circuit

An integrated circuit hierarchical design tool apparatus comprises a processor arranged to support a block coupling reconfiguration unit. The block coupling reconfiguration unit is capable of receiving block layout data comprising block placement, terminal location data and intra-block connectivity data. The block coupling reconfiguration unit is arranged to identify from the block layout data a block placement level block having a terminal respectively coupled to a plurality of other block placement level blocks by a plurality of nets, and to provide the block with an additional terminal capable of providing the same function as the terminal. The block coupling reconfiguration unit is also arranged to replace a net of the plurality of nets that is coupled to the terminal with a replacement net coupled to the additional terminal.