93 results about "Routing congestion" patented technology

A method, apparatus, and system are described, which generally relate to an integrated circuit having an interconnect. The flow control logic for the interconnect applies a flow control splitting protocol to permit transactions from each initiator thread and / or each initiator tag stream to be outstanding to multiple channels in a single aggregate target at once, and therefore to multiple individual targets within an aggregate target at once. The combined flow control logic and flow control protocol allows the interconnect to manage simultaneous requests to multiple channels in an aggregate target from the same thread or tag at the same time.

A method of estimating routing congestion between pins in a net of an integrated circuit design, by establishing one or more potential routes between the pins which pass through buckets in the net, assigning a probabilistic usage to each bucket based on any partial blockage of the wiring tracks in each bucket, and computing routing congestion for each bucket using its probabilistic usage. When the net is a two-pin net that is a part of a larger multi-pin net, and a tree is constructed to bridge the two-pin net to another pin of the multi-pin net. The routing congestion for each bucket is computed as a ratio of the bucket usage to bucket capacity. For L-shaped routes (having at least one bend in a bucket), the probabilistic usage is proportional to a scale factor a which is a ratio of a minimum number of available wiring tracks for a given route to a sum of minimum numbers of available wiring tracks for all possible routes. For Z-shaped routes (having at least two bends in two respective buckets), the probabilistic usage is equal to a ratio of a minimum capacity of a given route to a sum of minimum capacities of all routes having an associated orientation with the given route. Assignment of the usage values may entail the creation of a temporary usage map of the net buckets with an initial value of zero usage in every temporary usage map bucket, thereafter storing usage values in corresponding buckets of the temporary usage map, and deriving a final usage map from the temporary usage map.

One embodiment of the present invention provides a system that optimizes a circuit design during a logic design stage to reduce routing congestion during a placement and routing stage. During operation, this system identifies a first circuit structure in the circuit design which is expected to cause routing congestion during the placement and routing stage. Next, the system generates a second circuit structure which is functionally equivalent to the first circuit structure, and is not expected to cause routing congestion during the placement and routing stage. The system then replaces the first circuit structure in the circuit design with the second circuit structure, thereby mitigating routing congestion during the placement and routing stage.

Disclosed are embodiments of a method, service, and computer program product for performing yield-aware IC routing for a design. The method performs an initial global routing which satisfies wiring congestion constraints. Next, the method performs wire spreading and wire widening on the global route, layer by layer, based on, for example, a quadratic congestion optimization. Following this, timing closure is performed on the global route using results of the wire spreading and wire widening. Post-routing wiring width and wire spreading adjustments are made using the critical area yield model. In addition, the method allows for the optimization of already-routed data.

A layout circuit is provided, comprising standard cells, a spare cell, combined tie cells and normal filler cells. The standard cells are disposed and routed on a layout area. The spare cell is added on the layout area and provided for replacing one of the standard cells while adding or changing functions later. The combined tie cells are added on the layout area. The normal filler cells are added on the rest of the layout area. The combined tie cell comprises a tie-high circuit, a tie-low circuit and a capacitance circuit. Some standard cells are disposed near at least one combined tie cell for avoiding routing congestion between the combined tie cells and the replaced standard cell. A circuit layout method is also provided.

Systems and methods are disclosed for modifying the hierarchy of a System-on-Chip and other circuit designs to provide better routing and performance as well as more effective power distribution. A user specifies desired modifications to the design hierarchy and then the system automatically alters the hierarchy by performing group, ungroup, and move operations to efficiently and optimally implement the desired hierarchy modifications. Any modifications to port and signal names are automatically resolved by the system and the resultant RTL matches the function of the input RTL. The user then evaluates the revised hierarchy with regard to power distribution and routing congestion, and further hierarchy modifications are performed if necessary. A widget user interface facility is included to allow user-guided direction of hierarchy modifications in an iterative fashion.

Distributed processing LDPC (Low Density Parity Check) decoder. A means is presented herein that includes an LDPC decoding architecture leveraging a distributed processing technique (e.g., daisy chain) to increase data throughput and reduce memory storage requirements. Routing congestion and critical path latency are also improved thereby. Each daisy chain includes a number of registers, and a number of localized MUXs (e.g., MUXs having merely 2 inputs each). The means presented herein also does not contain any barrel shifters, high fan-in multiplexers, or interconnection networks; therefore, the critical path is relatively short and it can also be pipelined to further increase data throughput. If desired, a communication device can include multiple configurations of such daisy chains to accommodate the decoding of various LDPC coded signals (e.g., such as for an application and / or communication device that must decoded LDPC codes using different low density parity check matrices).

The scan flipflops on a semiconductor chip are stitched together to form one or more scan chains, located in one or more standard cell placement regions, after the optimal physical location of each scan flip-flop has been determined. As a result, the total length of the scan chain wires is substantially reduced, thereby reducing on-chip wiring congestion, flip-flop load capacitance, and flipflop power dissipation.