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: 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 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: 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: Some embodiments provide a method of designing a configurable integrated circuit (“IC”) with several configurable circuits. The method receives a design having several sets of operations for the configurable circuits to perform in different operational cycles. For at least a first set of operations that has a start operation and an end operation, the method assigns a particular operation in the first set to a first operational cycle based at least partially on the position of the particular operation with respect to the start and end operations.

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 a distribute signals throughout the IC.

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 reconfigurable integrated circuit (“IC”) that has several reconfigurable circuits, each having several configurations for several configuration cycles. The reconfigurable circuits include several time-extending reconfigurable circuits. During the operation of the IC, each particular time-extending reconfigurable circuit maintains at least one of its configurations over at least two contiguous cycles, in order to allow a signal to propagate through a signal path, which contains the particular time-extending circuit, within a desired amount of time.

Abstract: A novel method for designing an integrated circuit (“IC”) by rescaling an original set of circuits in a design of the IC is disclosed. The original set of circuits to be rescaled includes sequential nodes, combinational nodes, and interconnects. Each sequential node is associated with a phase of a clock. The method generates a rescaled set of circuits that includes multiple replica sets of the circuits. Each replica set of circuits includes sequential nodes, combinational nodes, and interconnects that are identical to nodes and interconnects in the original set of circuits. Each sequential node is associated with a phase of a clock that is at a fraction of the phase of its corresponding sequential element in the original set. The method connects nodes in each replica set of circuits to a logically equivalent node in another replica set. The method replaces the original set of circuits with the rescaled set of circuits.

Abstract: Some embodiments provide a method that defines a set of connections that connect the nodes in a configurable node array. The method identifies different sets of connections for connecting a set of the nodes. For each identified set of connections, the method computes a metric score that quantifies a quality of the identified set of connections. The method then selects one of the identified sets of connections to connect the configurable nodes in the array.

Abstract: Some embodiments of the invention provide a configurable integrated circuit (IC). The IC includes a logic circuit for receiving input data sets and configuration data sets and performing several functions on the input data sets. Each configuration data set specifies a particular function that the logic circuit has to perform on the input data set. The IC also includes a connection circuit for supplying sets of the configuration data to the logic circuit at a particular rate for at least a particular time period. At least two supplied configuration data sets are different and configure the logic circuit to perform two different functions on the input data.

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 configurable integrated circuit (IC) comprising multiple deskew circuits for delaying data passage. Each of the deskew circuits comprises a stepwise delay circuit with multiple outputs and an input selection circuit with multiple inputs. Multiple outputs connect to multiple inputs. In some embodiments the configurable IC is a subcycle reconfigurable IC. In some such embodiments each of the deskew circuits further includes a space-time load control circuit for commanding the stepwise delay circuit to load during a selected subcycle. In some embodiments the multiple deskew circuits send data to a trigger circuit. In some such embodiments the trigger circuit triggers a trace buffer to stop recording a data stream. In some such embodiments the trigger circuit triggers the trace buffer to stop after a programmable delay.

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: For an integrated circuit (IC) that retrieves data from a memory device external to the IC, a novel memory interface module that generates a sampling clock to the memory device and samples the retrieved data is described. The memory interface module adjusts the frequency of the sampling clock and selects a sampling time for sampling the retrieved data. The memory interface includes a training module that monitors a data pin of the memory device for transitions. The training module searches and records the earliest transition and the latest transition with respect to the period of the sampling clock. The memory interface module uses the earliest transition and the latest transition to determine an interval of data uncertainty (uncertainty interval) for the data pin. The memory interface module facilitates determining a new sampling time and a new sampling clock frequency based on the uncertainty intervals.

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 of the invention provide a programmable system in package (“PSiP”). The PSiP includes a single IC housing, a substrate and several IC's that are arranged within the single IC housing. At least one of the IC's is a configurable IC. In some embodiments, the configurable IC is a reconfigurable IC that can reconfigure more than once during run time. In some of these embodiments, the reconfigurable IC can be reconfigured at a first clock rate that is faster (i.e., larger) than the clock rates of one or more of the other IC's in the PSiP. The first clock rate is faster than the clock rate of all of the other IC's in the PSiP in some embodiments.

Abstract: Some embodiments provide an integrated circuit (‘IC’). The IC includes multiple configurable circuits that configurably perform operations of a user design based on configuration data. The IC also includes a configurable trigger circuit that receives a set of configuration data that specifies an operational event. The configurable trigger circuit also determines whether the operational event has occurred during implementation of the user design of the IC. Additionally, the operational trigger event outputs a trigger signal upon determining that the operational trigger event has occurred.

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 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.