Abstract: A portion of a logic emulation system is configured to sample logic values from the portion of the emulation system that is used to emulate the user digital logic design. These sampled values are then multiplexed by the emulation system to a logic analysis device. Typically, this is a commercially-available logic analyzer. To achieve this functionality, the emulation system is provided with a clock signal that has a higher frequency than the emulation clock signal received from the target or user system. This high speed clock signal is provided to logic analyzer as a strobe signal and controls the transfer of words of logic values from the emulation system to the logic analyzer. As a result, the number of signals that the logic analyzer can effectively sample for a cycle of the emulation clock is increased.

Abstract: A portion of a logic emulation system is configured to sample logic values from the portion of the emulation system that is used to emulate the user digital logic design. These sampled values are then multiplexed by the emulation system to a logic analysis device. Typically, this is a commercially-available logic analyzer. To achieve this functionality, the emulation system is provided with a clock signal that has a higher frequency than the emulation clock signal received from the target or user system. This high speed clock signal is provided to logic analyzer as a strobe signal and controls the transfer of words of logic values from the emulation system to the logic analyzer. As a result, the number of signals that the logic analyzer can effectively sample for a cycle of the emulation clock is increased.

Abstract: A method for partitioning a logic circuit is provided for emulation under a virtual wires method using programmable logic devices. Because a virtual wires systems replace pin constraints by a corresponding gate constraint, partitioning for a virtual wires system applies novel constraints and algorithms. In one embodiment, partitioning is provided under a "flat mincut" approach in conjunction with a virtual wire cost constraint. In another embodiment, partitioning is provided under a "hierarchical mincut" in conjunction with a virtual wire cost constraint.

Abstract: A stimulus engine for a logic simulation system is used to interpret a stimulus language and generate test patterns as input to a logic simulator. The stimulus language allows a large test pattern set to be represented as a program. Special purpose hardware interprets this program and generates a sequence of input/output events to the logic simulator. The program interpretation is performed while the logic simulation is executing. Special purpose hardware is used to insure that the stimulus engine is able to generate the input/output events at a rate which does not slow down the logic simulator.