Abstract: Progressively optimized clock tree/mesh construction is performed concurrently with placement of all remaining objects. Clock tree/mesh is specified loosely for initial placement, then followed by progressive detailed placement. In particular, preferred approach provides automated and reliable solution to clock tree/mesh construction, occuring concurrently with placement process so that clock tree wiring and buffering considers and influences placement and wiring of all other objects, such as logic gates, memory elements, macrocells, etc. Hence, in this concurrent manner, clock tree/mesh pre-wiring and pre-buffering may be based on construction of approximate clock tree using partitioning information only, i.e., prior to object placement. Further, present approach provides modified DME-based clock tree topology construction without meandering, and recursive algorithm for buffered clock tree construction.

Abstract: A design tool for integrated circuits includes a placement tool which concurrently places logic gates and interconnect. In one embodiment, the logic gates are placed into bins and virtual buffers are inserted between logic gates mapped to different bins. Placement and interconnect wire lengths and densities are successively improved leading to removal of some buffers and actualization of the virtual buffers.

Abstract: Speed, size, and power trade-offs of a VLSI combinational circuit are optimized through iterative restructuring. First, timing analysis for the circuit is performed (102) to find the critical path through the circuit (104). Then, a gate is selected from the critical path (106), and a window is contracted around the gate (108). Within the window, alternate structures are constructed (110) and sized (112). The best alternative is substituted into the window (114), and the new circuit is resized (116). If the new circuit is not an improvement over the old (118), then the original window is replaced (120). In any case, this is repeated for each gate in the circuit (124). The entire process is then repeated until either user constraints are met, or the circuit doesn't change (122).

Abstract: A slack time, based on a required and actual delay time, is calculated for each node in a circuit (302). For each element in the circuit, a sensitivity (304) and a figure of merit (306) is calculated. A variance is determined for the calculated figure of merits (308). The circuit element having the smallest absolute figure or merit is optimized when the variance is smaller than a predefined threshold (310, 312).

Abstract: A process and implementing computer system (13) for optimally sizing elements of an integrated circuit includes determining actual arrival times and required arrival times (403) for processed signals at all nodes within the integrated circuit and determining the slack or difference (405) between arrival and required times for each node. If the actual arrival time for a particular node is after the time required to meet a predetermined design constraint of the node (407), a determination (411) is made regarding the effect of that element on the nodal slack for an incremental increase in the size of that element. Thereafter an element is selected (413) for sizing increase (415) in accordance with a weighting function and the process is repeated until all of the nodes in the integrated circuit have positive slack times (407, 409).

Abstract: A process and implementing computer system (13) for optimally sizing elements of an integrated circuit includes determining actual arrival times and required arrival times (403) for processed signals at all nodes within the integrated circuit and determining the slack or difference (405) between arrival and required times for each node. If the actual arrival time for a particular node is after the time required to meet a predetermined design constraint of the node (407), a determination (411) is made regarding the effect of that element on the nodal slack for an incremental increase in the size of that element. Thereafter an element is selected (413) for sizing increase (415) in accordance with a weighting function and the process is repeated until all of the nodes in the integrated circuit have positive slack times (407, 409).

Abstract: A process and implementing computer system (13) for optimally sizing elements of an integrated circuit includes determining actual arrival times and required arrival times (403) for processed signals at all nodes within the integrated circuit and determining the slack or difference (405) between arrival and required times for each node. If the actual arrival time for a particular node is after the time required to meet a predetermined design constraint of the node (407), a determination (411) is made regarding the effect of that element on the nodal slack for an incremental increase in the size of that element. Thereafter an element is selected (413) for sizing increase (415) in accordance with a weighting function and the process is repeated until all of the nodes in the integrated circuit have positive slack times (407,409).