Abstract: Some embodiments provide a circuit for accessing stored data in a configurable IC that includes several configurable circuits. The IC also includes several storage circuits. Each storage circuit has (1) several storage elements for storing data for the configurable circuits, and (2) output circuitry for outputting data stored in the storage elements. The output circuitry includes a first set of interconnects for receiving at least a first repeating periodic signal and for periodically outputting data from at least two storage elements to the configurable circuits.

Abstract: A system and method of determining paths of components when placing and routing configurable circuits. The method identifies a probabilistic data flow through multiple components using a simplified connection matrix. The simplified connection matrix is used to determine a probabilistic data flow through the components without data flowing from any component to itself. The probabilistic data flow is used to determine a probabilistic data flow through the components with some of the components having data flowing from themselves back to themselves. The probabilistic data flow through each component and the number of inputs of the components are used to determine a cost for each component. The cost of a path through the circuit is determined from the costs of the individual components in the path. The costs of the components are used to determine which path of components to use.

Abstract: An integrated circuit (IC) with a novel configurable routing fabric is provided. The configurable routing fabric has signal paths that propagate signals between user registers on user clock cycles. Each signal path includes a set of configurable storage elements and a set of configurable logic elements. Each configurable storage element in the path is reconfigurable on every sub-cycle of the user clock cycle to either store an incoming signal or to pass the incoming signal transparently.

Abstract: Some embodiments of the invention provide a configurable integrated circuit (“IC”). The configurable IC includes a set of configurable logic circuits for configurably performing a set of functions. The configurable IC also includes a set of configurable routing circuits for routing signals to and from the configurable circuits. During several operational cycles of the configurable IC, a set of data registers are defined by the configurable routing circuits. These data registers may be used wherever a flip-flop can be used.

Abstract: A novel configurable integrated circuit (IC) that has several configurable circuits for configurably performing different operations is provided. During the operation of the IC, each particular configurable circuit performs a particular operation that is specified by a particular configuration data set for the particular configurable circuit. While the IC operates and a first set of configurable circuits performs a first set of operations, configuration data is loaded from the outside of the IC for configuring a second set of configurable circuits. The configurable IC includes a configuration network for rapid loading configuration data in the IC from outside of the IC. The configuration network is a pipelined network.

Abstract: An integrated circuit (IC) that includes multiple clock domains is provided. Each clock domain operates at a user specified data rate, and the data rates of at least two of the clock domains are related by a common base clock. The specified data rate of each clock domain is controlled by a modulating signal. Each clock domain includes reconfigurable circuits that operate on the common base clock, and the modulating signal controls the data rate of the clock domain by modulating reconfiguration of the reconfigurable circuits. The reconfigurable circuits reconfigure when the modulating signal enables the reconfiguration.

Abstract: A novel integrated circuit (IC) that configurably distributes clocks from multiple clock sources to multiple sets of circuits is described. The IC includes multiple clock sources and multiple clock domains. Each clock domain includes a clock signal and a control signal. The clock signal is configurably selected from one of the multiple clock sources. The control signal is synchronized to the clock signal. The IC also includes multiple configurable circuits. A configurable circuit can configurably operate in one of the clock domains by selecting and using the control signal and the clock signal of the clock domain.

Abstract: Some embodiments provide an integrated circuit (“IC”) with a primary circuit structure. The primary circuit structure is for performing multiple operations that implement a user design. The primary circuit structure includes multiple circuits. The IC also includes a secondary monitoring structure for monitoring multiple operations. The secondary monitoring structure includes a network communicatively coupled to multiple circuits of the primary circuit structure. The secondary monitoring circuit structure is for analyzing the monitored operations and reporting on the analysis to a circuit outside of the IC.

Abstract: Some embodiments of the invention provide a configurable integrated circuit (“IC”). The configurable IC includes a set of multiplexers that each has a set of input terminals, a set of output terminals, and a set of select terminals. The set of multiplexers includes a group of multiplexers, where at least one input terminal of each multiplexer in the group is a permanently inverting input terminal. During at least a set of cycles during the operation of the configurable IC, several multiplexers in the group of multiplexers are used to implement a particular function.

Abstract: Some embodiments provide a configurable IC that includes a configurable routing fabric with storage elements. In some embodiments, the routing fabric provides a communication pathway that routes signals to and from source and destination components. The routing fabric of some embodiments provides the ability to selectively store the signals passing through the routing fabric within the storage elements of the routing fabric. In this manner, a source or destination component continually performs operations (e.g., computational or routing) irrespective of whether a previous signal from or to such a component is stored within the routing fabric. The source and destination components include configurable logic circuits, configurable interconnect circuits, and various other circuits that receive or distribute signals throughout the configurable IC.

Abstract: A method of detailed placement for ICs is provided. The method receives an initial placement and iteratively builds sets of constraints for placement of different groups of cells in the IC design and uses a satisfiability solver to resolve placement violations. In some embodiments, the constraints include mathematical expressions that express timing requirements. The method in some embodiments converts the mathematical expressions into Boolean clauses and sends the clauses to a satisfiability solver that is only capable of solving Boolean clauses. In some embodiments, the method groups several cells in the user design and several sites on the IC fabric and uses the satisfiability solver to resolve all placement issues in the group. The satisfiability solver informs placer after each cell is moved to a different site. The method then dynamically builds more constraints based on the new cell placement and sends the constraints to the satisfiability solver.

Abstract: Some embodiments provide an IC with configuration context switchers. The IC includes several configurable circuits, each of which configurably performs one of several operations at any given time, based on the configuration data set that it receives at that time. The IC includes several storage circuits for storing several configuration data sets for each of the configurable circuits. The IC also includes a context switching interconnect circuit for switchably connecting the configurable circuit to different sets of storage circuits to receive different sets of configuration data sets. The context switcher includes one or more stages for re-timing the data coming from the configuration storage elements. The stages can include interconnect circuitry or storage circuitry. Some embodiments build one of the stages in the configuration data storage elements. Some embodiments encode the configuration data bits and hence utilize a decoder in the context switcher to decode the encoded configuration data.

Abstract: Some embodiments provide a circuit for accessing stored data in a configurable IC that includes several configurable circuits. The IC also includes several storage circuits. Each storage circuit has (1) several storage elements for storing data for the configurable circuits, and (2) output circuitry for outputting data stored in the storage elements. The output circuitry includes a first set of interconnects for receiving at least a first repeating periodic signal and for periodically outputting data from at least two storage elements to the configurable circuits.

Abstract: An integrated circuit (“IC”) having configurable logic circuits for configurably performing multiple different logic operations based on configuration data is provided. The IC includes a configurable routing fabric for configurably routing signals among configurable logic circuits. The configurable routing fabric includes a particular wiring path that connects an output of a source circuit to inputs of a destination circuit. The particular wiring path includes a first path and a second path that is parallel to the first path. The first and second paths are for configurably storing output signals of the source circuit. The first path connects to a first input of the destination circuit and the second path connects to a second input of the destination path.

Abstract: An abstract decision module primitive for placement within a logical representation (i.e., a netlist) of a circuit design is described. The decision module primitive receives as inputs alternative solutions for a given function or segment of a netlist. The alternative solutions include functionally equivalent, but structurally different implementations of the function or segment of the netlist. The decision module primitive alternatively selects between connecting one of the inputs to the netlist to provide a complete functional definition for the netlist based on constraint information. The selected input of the decision module may be updated as additional constraint information is determined throughout the various stages of the design process. In addition, alternative solutions for a given function or segment of the netlist may be added to and/or removed from the inputs of a decision module as additional constraint information is identified.

Abstract: Some embodiments provide a method of monitoring the implementation of a user design in a configurable integrated circuit (IC). The method receives a user design for an IC and optimizes the user design to produce a second IC design. The optimization results in the elimination of circuit element(s). The method defines the second IC design for the configurable IC and generates output data for the eliminated circuit element(s) to allow for monitoring the user design.

Abstract: A method of monitoring operations of a set of ICs. The method loads a first set of configuration data into a first IC for configuring a group of configurable circuits of the first IC to perform operations of a user design. The method receives a definition of an event based on values of a set of signals in the user design and a set of corresponding actions to take when the event occurs. The set of signals includes at least one signal received from a second IC. The method generates an incremental second set of configuration data based on the definition of the event and the set of corresponding actions. While the first IC is performing the operations of the user design, the method loads the incremental second set of configuration data into the first IC and monitors the signals received from the second IC at the first IC.

Abstract: An application-specific integrated circuit (ASIC) is provided. The ASIC includes a group of non-configurable circuits customized for performing operations for a particular use. The ASIC also includes a set of reconfigurable circuits for configurably performing a set of operations based on configuration data. The ASIC also includes a configuration and monitoring network that receives a set of signals from the non-configurable circuits of the ASIC. The configuration and monitoring network also receives incremental sets of configuration data while the ASIC is performing operations of the user design. Each incremental set of data is used for reconfiguring the configuration and monitoring network (i) to monitor one or more signals in the set of signals and (ii) to take a set of actions when values of the monitored signals satisfy a condition.

Abstract: A method of monitoring operations of a set of ICs. The method loads a first set of configuration data into a first IC for configuring a group of configurable circuits of the first IC to perform operations of a user design. The method receives a definition of an event based on values of a set of signals in the user design and a set of corresponding actions to take when the event occurs. The set of signals includes at least one signal received from a second IC. The method generates an incremental second set of configuration data based on the definition of the event and the set of corresponding actions. While the first IC is performing the operations of the user design, the method loads the incremental second set of configuration data into the first IC and monitors the signals received from the second IC at the first IC.

Abstract: An integrated circuit (“IC”) that includes a configurable routing fabric with controllable storage elements is described. The routing fabric provides a communication pathway that routes signals to and from source and destination components. The routing fabric may provide the ability to selectively store the signals passing through the routing fabric within the storage elements of the routing fabric. In this manner, a source or destination component may continually perform operations (e.g., computational or routing) irrespective of whether a previous signal from or to such a component is stored within the routing fabric. The source and destination components include configurable logic circuits, configurable interconnect circuits, and various other circuits that receive or distribute signals throughout the IC.