Abstract: A number of enhanced logic elements (LEs) are provided to form a FPGA. Each enhanced LE comprises a multiple input-single output truth table, and a complementary pair of master-slave latches having a data, a set and a reset input. Each enhanced LE further comprises a plurality of multiplexers and buffers, and control logic. Additionally, the improved FPGA further comprises a network of crossbars, a context bus, a scan register, and a plurality of trigger circuitry. As a result, each LE may be individually initialized, its signal state frozen momentarily, the frozen state be read, trace data be output, and trigger inputs be conditionally generated. Furthermore, the enhanced LEs may be used for “level sensitive” as well as “edge sensitive” circuit design emulations.

Abstract: Data processing resources are distributively provided to an emulation system to locally and correspondingly generate configuration signals to configure selected ones of reconfigurable logic and interconnect resources of corresponding collections of reconfigurable logic and interconnect resources, to emulate corresponding partitions of an IC design. In one embodiment, the distributed data processing resources further locally and correspondingly determine inteconnect routing within the selected ones of the reconfigurable logic resources of the corresponding collections of reconfigurable logic resources. In one embodiment, the distributed data processing resources are disposed on logic boards having emulation ICs that include the reconfigurable logic and interconnect resources. In other embodiments, at least some of the distributed data processing resources are disposed on the emulation ICs.

Abstract: A regionally time multiplexed emulation system includes an emulator for emulating a circuit design. The emulator includes a plurality of reconfigurable logic devices with buffered I/O pins and reconfigurable logic elements. The reconfigurable logic devices are reconfigurable to emulate a circuit design using at least one user clock to clock the logic elements and at least one signal routing clock to time multiplex the routing of emulation signals between the reconfigurable logic devices, with the at least one signal routing clock being independent of the at least one user clock.

Abstract: A number of enhanced logic elements (LEs) are provided to form a reconfigurable integrated circuit (IC). Each enhanced LE comprises a multiple input-single output truth table, and a complementary pair of master-slave latches having a data, a set and a reset input. Each enhanced LE further comprises a plurality of multiplexers and buffers, and control logic. Additionally, the improved IC may further comprises a scalable network of crossbars, a context bus, a scan register, and/or a plurality of trigger circuitry. As a result, each LE may be individually initialized, its signal state frozen momentarily, the frozen state be read, trace data be output, and trigger inputs be conditionally generated, making the IC particularly suitable for circuit design emulation. Furthermore, the enhanced LEs may be used for “level sensitive” as well as “edge sensitive” circuit design emulations.

Abstract: Data processing resources are distributively provided to an emulation system to locally and correspondingly generate testing stimuli, and applying the generated testing stimuli to partitions of an IC design to be emulated. In one embodiment, the distributed data processing resources further locally and correspondingly retrieve state data of emulation state circuit elements, analyze the retrieved state data for one or more events, and report the one or more events upon their detection. In one embodiment, the distributed data processing resources are disposed on logic boards of an emulation system. In other embodiments, at least some of the distributed data processing resources are disposed on the emulation ICs of the logic boards.

Abstract: A scalable emulation system is disclosed. The basic embodiment of the emulation system includes a number of logic boards with logic chips that are reconfigurable to emulate circuit elements of a circuit design. The basic embodiment further includes a number of interconnect boards coupled to at least the logic boards. Each of the interconnect boards includes interconnect chips that are reconfigurable to selectively interconnect the logic chips of different ones of the logic boards. Additionally, at least each of a subset of the interconnect boards includes a number of expansion connectors for facilitating expansion of the emulation system in one or more selected ones of expansion orientations through coupling of at least one or more substantial replicates of the basic embodiment.

Abstract: An integrated circuit (IC) includes a number of function blocks (FB), of which at least one is re-configurable. Each of the FBs may be a reconfigurable function or a non-reconfigurable function or recursively expanded with additional “nested” function blocks. The IC further includes a number of input pins, a number of output pins, and a number of crossbar devices. The elements, at least at the IC level, are coupled in a manner such that all input signals are provided to the FBs through a first subset of the crossbar devices, all internal signals are routed from one FB to another FB through a second subset of crossbar devices, and all output signals are routed from the FBs to the output pins through a third subset of crossbar devices. To increase routability and speed each of the crossbar device output has a single fanout. Additionally, each of the crossbar devices may provide only one input to each other crossbar device.

Abstract: A crossbar device includes a first set of input lines and a second set of output lines. A plurality of chains of pass transistors are provided to selectively couple the input lines to the output lines in a reduced parasitic capacitive loading manner. Further, memory elements and decoder logic are provided to facilitate control of the selective coupling. Additionally, a low power application of multiple crossbar devices to a reconfigurable circuit block is improved by having each memory element of a crossbar device be provided with a supply voltage higher by a Vth to maintain the input voltage of corresponding output buffers at Vdd,. Further, an application of multiple crossbar devices to a reconfigurable circuit block is improved by coupling a control circuitry via a control line to all output buffers of the interconnected crossbar devices to force the output buffers to a known state at power-on.

Abstract: An emulation system equipped to emulate multiple circuit designs concurrently is disclosed. The emulation system includes an emulator having reconfigurable emulation resources for emulating circuit designs, and a host system programmed with programming instructions that operate to generate coordinated configuration information for a number of circuit designs to enable the reconfigurable emulation resources to be configured in a coordinated manner to allow the circuit designs to be emulated concurrently.

Abstract: An emulation system equipped to emulate multiple circuit designs concurrently is disclosed. The emulation system includes an emulator having reconfigurable emulation resources for emulating circuit designs, and a host system programmed with programming instructions that operate to generate coordinated configuration information for a number of circuit designs to enable the reconfigurable emulation resources to be configured in a coordinated manner to allow the circuit designs to be emulated concurrently.

Abstract: A number of enhanced logic elements (LEs) are provided to form a FPGA. Each enhanced LE comprises a multiple input-single output truth table, and a complementary pair of master-slave latches having a data, a set and a reset input. Each enhanced LE further comprises a plurality of multiplexers and buffers, and control logic. Additionally, the improved FPGA further comprises a network of crossbars, a context bus, a scan register, and a plurality of trigger circuitry. As a result, each LE may be individually initialized, its signal state frozen momentarily, the frozen state be read, trace data be output, and trigger inputs be conditionally generated. Furthermore, the enhanced LEs may be used for “level sensitive” as well as “edge sensitive” circuit design emulations.

Abstract: A number of enhanced logic elements (LEs) are provided to form a [FPGA] reconfigurable integrated circuit (IC). Each enhanced LE comprises a multiple input-single output truth table, and a complementary pair of master-slave latches having a data, a set and a reset input. Each enhanced LE further comprises a plurality of multiplexers and buffers, and control logic. Additionally, the improved [FPGA] IC may further comprise[s] a scalable network of crossbars, a context bus, a scan register, and/or a plurality of trigger circuitry. As a result, each LE may be individually initialized, its signal state frozen momentarily, the frozen state be read, trace data be output, and trigger inputs be conditionally generated, making the IC particularly suitable for circuit design emulation. Furthermore, the enhanced LEs may be used for “level sensitive” as well as “edge sensitive” circuit design emulations.

Abstract: An integrated circuit is described as comprising a plurality of logic elements (LEs), each of which having a plurality of outputs, and a partial scan register. The plurality of LEs are operative to generate a plurality of output signals in response to a plurality of input signals correspondingly applied to the LEs. The partial scan register is reconfigurably coupled to select ones of the LEs such that, when enabled, the partial scan register is operative to capture and output on a scan bus a record of signal state values circuit elements emulated by the selected LEs in a particular clock cycle of an operating clock, wherein the partial scan register is enabled with application of a scan clock appropriately scaled to the operating clock.

Abstract: A number of enhanced logic elements (LEs) are provided to form a FPGA. Each enhanced LE comprises a multiple input-single output truth table, and a complementary pair of master-slave latches having a data, a set and a reset input. Each enhanced LE further comprises a plurality of multiplexers and buffers, and control logic. Additionally, the improved FPGA further comprises a network of crossbars, a context bus, a scan register, and a plurality of trigger circuitry. As a result, each LE may be individually initialized, its signal state frozen momentarily, the frozen state be read, trace data be output, and trigger inputs be conditionally generated. Furthermore, the enhanced LEs may be used for "level sensitive" as well as "edge sensitive" circuit design emulations.

Abstract: A method and apparatus for tracing any node in an emulator, including hidden nodes of a circuit design, includes maintaining a correspondence between physically observable nodes and hidden nodes of the circuit design being emulated. The correspondence identifies how values of the hidden nodes are to be determined based on corresponding ones of the physically observable nodes. The value of a hidden node is determined by obtaining the values of the corresponding physically observable nodes and identifying the value of the hidden node based on the correspondence between the corresponding physically observable nodes and the hidden node.

Abstract: A scalable multi-level multi-stage network topology is employed to interconnect reconfigurable logic elements within the special purpose FPGA, inter-FPGA, inter-logic boards, and inter-backplanes. More specifically, under the presently preferred embodiment, an on-chip 3-stage inter-logic element crossbar network is provided to each special purpose FPGA for interconnecting the reconfigurable logic elements and the I/O pins of the special purpose FPGA. A two level three-stage inter-FPGA hybrid crossbar network is provided to interconnect the special purpose FPGAs and I/O pins of the logic board. The two-level three-stage inter-FPGA hybrid crossbar network consists of two stages of programmable crossbars and one stage of one or more special purpose FPGAs used for interconnection only. The exact number of special purpose FPGAs to be used for interconnection only on a particular logic board is dependent on the specific circuit design being emulated.

Abstract: A computer system is programmed with logic for automatically removing timing hazards from a circuit design. More specifically, the computer system is programmed with logic for automatically detecting and resolving clock gating as well as clock division timing hazards from the circuit design. In one embodiment, the computer system is further programmed with logic for logically organize timing hazards into levels, after the clock gating timing hazards have been resolved, and then resolving clock division timing hazards recursively. In one adaptation, the computer system is a component of a hardware emulation system.

Abstract: A computer system is programmed with logic for automatically removing timing hazards from a circuit design. More specifically, the computer system is programmed with logic for automatically detecting and resolving clock gating as well as clock division timing hazards from the circuit design. In one embodiment, the computer system is further programmed with logic for logically organize timing hazards into levels, after the clock gating timing hazards have been resolved, and then resolving clock division timing hazards recursively. In one adaptation, the computer system is a component of a hardware emulation system.

Abstract: A method and apparatus for tracing any node in an emulator, including hidden nodes of a circuit design, includes maintaining a correspondence between physically observable nodes and hidden nodes of the circuit design being emulated. The correspondence identifies how values of the hidden nodes are to be determined based on corresponding ones of the physically observable nodes. The value of a hidden node is determined by obtaining the values of the corresponding physically observable nodes and identifying the value of the hidden node based on the correspondence between the corresponding physically observable nodes and the hidden node.

Abstract: A number of enhanced logic elements (LEs) are provided to form a FPGA. Each enhanced LE comprises a multiple input-single output truth table, and a complementary pair of master-slave latches having a data, a set and a reset input. Each enhanced LE further comprises a plurality of multiplexers and buffers, and control logic. Additionally, the improved FPGA further comprises a network of crossbars, a context bus, a scan register, and a plurality of trigger circuitry. As a result, each LE may be individually initialized, its signal state frozen momentarily, the frozen state be read, trace data be output, and trigger inputs be conditionally generated. Furthermore, the enhanced LEs may be used for "level sensitive" as well as "edge sensitive" circuit design emulations.