摘要:
A method for routing of some embodiments defines global routes for nets in an arbitrary region of a circuit layout in which each net has a set of pins. The method uses a first set of lines of measure the length of the global routes, a second set of lines to measure congestion of the global routes, and a third set of lines to partition the arbitrary region into a first set of sub-regions. For each net, the method identifies a global route that connects a group of first-set sub-regions that contain the net's set of pins.
摘要:
The present invention introduces a method for implementing a gridless non Manhattan router by modifying an existing gridless Manhattan router. In the method of the present invention, a tile based router that uses tiles to represent circuit geometry or free space between circuit geometry is first selected. Next, at least one tile routing layer of the tile based router is rotated to implement a diagonal wiring layer. The code of the router is then adjusted to ensure that a via that will connect a Manhattan layer to a non Manhattan layer (a diagonal layer) will fit within a tile on both layers.
摘要:
Some embodiments of the invention provide a method of decomposing a design layout. The method decomposes the layout into a tessellated graph with several edges. It then computes the capacity of the edges based on a interconnect line model that is used to connect elements in the design layout. The layout has two orthogonal coordinate axes. At least one interconnect line specified by the model is neither parallel nor perpendicular to the coordinate axes. Also, in some embodiments, some of the edges are neither parallel nor perpendicular to the coordinate axes.
摘要:
One embodiment of the invention is a method of specifying routes for a group of nets. The method identifies different routing solutions for the group of nets. It then selects the best routing solution.
摘要:
Some embodiments of the invention provide a method of specifying a cost function that represents the estimated distance between an external state and a set of states in a multi-state space that represents a region of a design layout. The method identifies a polygon that encloses the set of states. It then identifies vectors to project from the vertices of the polygon. Based on the projected vectors, the method identifies a set of distances that includes the distance between the polygon and each point in a set of points in the external state. The method then uses the identified set of distance to specify the cost function.
摘要:
Some embodiments of the invention provide a method for propagating a first piecewise linear function (PLF), which is defined over a first state, to a second state, which is a surface. In some embodiments, the space includes a set of states and a transition map that specifies a set of states that can be reached from each particular state. For instance, in some embodiments, the space is a graph that includes points, lines, and surfaces. The method projects vectors from points on the first state that are locations of inflection points in the first PLF. At each intersection of the boundary of the surface and one of the vectors, the method computes a cost. Based on the computed costs, the method specifying a second PLF that is defined over the second state.
摘要:
Some embodiments of the invention provide a method of for routing nets within a region of an integrated circuit (“IC”) layout. The method selects a net in the IC layout region. It then identifies a topological route for the selected net. From the selected net's topological route, this method then generates a geometric route for the selected net.
摘要:
Some embodiments of the invention provide a method of propagating a first cost function that is defined over a first state to a second slate in a space representing a design-layout region. In some embodiments, the space includes a set of states and a transition map that specifies a set of states that can be reached from each particular state. The space has several dimensional states. The method identifies several pairs of wedge vectors. Each vector has a tail, and each wedge-vector pair includes two vectors that are connected at their tails. The method assigns locations in the first state for the tails of at least some of the identified wedge-vector pairs. The method then uses the wedge-vector pairs that have assigned tail locations to propagate the first cost function.
摘要:
Some embodiments of the invention provide a method of routing nets in a region of a design layout. The region contains a plurality of nets and has multiple interconnect layers. The method identifies routes for a set of nets in the region, where some of the routes utilize vias to traverse multiple interconnect layers. The method then moves at least one via to improve the routing.
摘要:
Some embodiments of the invention provide a path-searching method. This method identifies two sets of states in a multi-state space, where at least some of the states have at least one dimension. It then performs an epsilon-optimal path search to identify an epsilon-optimal path between the two set of states. The epsilon-optimal path is a path that is within an epsilon of the optimal path between the two sets of states. During the espsilon optimal search, the method propagates a cost function that is defined over one state to another state.