24.4 Timing-Driven Steiner

8 8 8 Traditionally, rectilinear Steiner minimum trees (RSMT) are widely a a used for routing estimation in design optimizations like floorplan- 8 8 8 ning and physical synthesis. Since it optimizes wirelength, an RSMT 3 1 f 3 1 f 3 1 f 1 g,Imay take a "non-direct " route to a sink, which may give the de- g e3 3 signer an unnecessarily pessimistic view of the delay to the sink. 1 0 dld e d Previous works have addressed this issue through performance- 0 10 driven constructions, minimum Steiner arborescence, and critical C 3 C sink based Steiner constructions. Physical synthesis and routing s b s 4 b s 4 b flows have been reticent to adapt universal timing-driven Steiner constructions out of fear that they are too expensive (in terms of (a) Tree with (b) RSMT (c) MRSA routing resource and capacitance). This paper studies several differ- poor sink radiu