Abstract: A method for laying out an integrated circuit design based upon a netlist provided by a behavioral synthesis tool includes the steps of: (A) placing cells specified by the netlist in a layout area in a placement step, the cells including pins that are interconnected by nets; (B) verifying timing constraints in a timing verification step of the placed cells in the layout area; and (C) if the timing verification step indicates that timing does not verify in that the timing constraints are not met: (a) modifying the netlist pursuant to an engineering change order (ECO); and (b) making an ECO placement of at least one cell into the layout area by (i) picking an unplaced cell from a set of unplaced cells to be a picked cell; (ii) determining a target window within said layout area for the placement of said picked cell; (iii) mapping said picked cell inside said target window; (iv) removing said picked cell from said set of unplaced cells; (v) optimizing the placement of said picked cell by analyzing said picked ce

Abstract: A method for laying out an integrated circuit design based upon a netlist provided by a behavioral synthesis tool includes the steps of: (a) placing cells specified by the netlist in a layout area in a placement step, the cells including pins that are interconnected by nets; (b) verifying timing constraints in a timing verification step of the placed cells in the layout area; and (c) if the timing verification step indicates that timing does not verify in that the timing constraints are not met: (i) modifying the netlist pursuant to an engineering change order (ECO); and (ii) making an ECO placement of at least one cell into the layout area based upon the timing constraints while adjusting any affected nets as specified by the netlist. A layout tool implements the method on a computer system to form a portion of and integrated circuit fabrication system.

Abstract: A method of optimizing the placement of components of an integrated circuit to ensure that all circuit paths will meet their timing criteria, as well as to minimize area and total wire length is disclosed. The method employs a non-constant net weighting distribution along critical paths to encourage a mincut algorithm to place components so that path lengths are minimized as well as the entire nets coupled to paths. The magnitude of weights assigned are commensurate with the slack the path has with respect to its maximum delay constraint, as well as the level of method iteration. Any nets not deemed critical are assigned a minimum capacitance constraint to prevent them from becoming critical as a function of actual placement. Weights assigned to capacitively constrained nets are inversely proportional to the difference between the maximum capacitance allowed and the estimated capacitance of the current placement.

Abstract: In a method for providing routing between logic cells, the logic cells are arranged in rows. Intercell connectors within each row of logic cells are aligned, for example in the middle of the rows, to form channel boundaries. The intercell connectors are then channel routed in metal layers above the logic cells. Alternately, intercell connectors are placed within the logic cells, however, these intercell connectors are not necessarily aligned. For each intercell connector which is not on a boundary of a routing channel, a substitute connector is located at the boundary of a routing channel. The substitute connectors and the intercell connectors which are on the boundaries of the routing channels are channel routed. Length of routing segments are then adjusted to substitute connectors to extend to intercell connectors instead of the substitute connectors.

Abstract: A method sizes routing channels used to route pads to a logic core. Six channels are defined. The six channels include a first special channel, a second special channel, a left channel, a right channel, a bottom channel and a top channel. The first special channel is immediately below the logic core and within a span of the logic core. The second special channel is immediately above the logic core and within a span of the logic core. The left channel is adjacent to a left side of the logic core, the first special channel and the second special channel. The right channel is adjacent to a right side of the logic core, the first special channel and the second special channel. The bottom channel is adjacent to a bottom side of the left channel, the first special channel and the right channel. The top channel is adjacent to a top side of the left channel, the first special channel and the right channel.

Abstract: A method of routing interconnections of devices in a planar field by the use of a computer. The method effectively shortens the length of all interconnections, including interconnections which connect points on the same device, in accordance with design rules. Also, the layers constituting the planar field can be assigned weights to effectively minimize the appearance of interconnections in the layer having the highest assigned weight.