An improved electronic design automation (EDA) system employs field programmable gate arrays (FPGAs) for emulating prototype circuit designs. A circuit netlist file is down-loaded to the FPGAs to configure the FPGAs to emulate a functional representation of the prototype circuit. To check whether the circuit netlist is implemented properly, the FPGAs are tested functionally by applying input vectors thereto and comparing the resulting output of the FPGAs to output vectors provided from prior simulation. If the FPGAs fail such vector comparison, the FPGAs are debugged by inserting "read-back" trigger instructions in the input vectors, preferably corresponding to fail points in the applied vector stream. Modifying the input vectors with such read-back signals causes the internal states of latches and flip-flops in each FPGA to be captured when functional testing is repeated. Such internal state information is useful for debugging the FPGAs, and particularly convenient because no recompilation of the circuit netlist is required. A similar approach which also uses the read-back feature of FPGAs is employed to debug FPGAs coupled to a target system which appears to fail during emulation runs.

Method and apparatus for debugging reconfigurable emulation systems

A method and apparatus for fabricating known good semiconductor dice are provided. The method includes the steps of: testing the gross functionality of dice contained on a semiconductor wafer; sawing the wafer to singulate a die; and then testing the die by assembly in a carrier having an interconnect adapted to establish electrical communication between the bond pads on the die and external test circuitry. The interconnect for the carrier can be formed using different contact technologies including: thick film contact members on a rigid substrate; self-limiting contact members on a silicon substrate; or microbump contact members with a textured surface. During assembly of the carrier, the die and interconnect are optically aligned and placed into contact with a predetermined contact force. This establishes an electrical connection between the contact members on the interconnect and the bond pads of the die. In the assembled carrier the die and interconnect are biased together by a force distribution mechanism that includes a bridge clamp, a pressure plate and a spring clip. Following testing of the die, the carrier is disassembled and the tested die is removed.

Method and apparatus for manufacturing known good semiconductor die

A system for physical emulation of electronic circuits or systems includes a data entry workstation where a user may input data representing the circuit or system configuration. This data is converted to a form suitable for programming an array of programmable gate elements provided with a richly interconnected architecture. Provision is made for externally connecting VLSI devices or other portions of a user's circuit or system. A network of internal probing interconnections is made available by utilization of unused circuit paths in the programmable gate arrays.

Apparatus for emulation of electronic hardware system

A hardware emulation system is disclosed which reduces hardware cost by time-multiplexing multiple design signals onto physical logic chip pins and printed circuit board. The reconfigurable logic system of the present invention comprises a plurality of reprogrammable logic devices, and a plurality of reprogrammable interconnect devices. The logic devices and interconnect devices are interconnected together such that multiple design signals share common I/O pins and circuit board traces. A logic analyzer for a hardware emulation system is also disclosed. The logic circuits necessary for executing logic analyzer functions is programmed into th e programmable resources in the logic chips of the emulation system.

Emulation system with time-multiplexed interconnect

The coverification system includes a reconfigurable computing system (hereinafter “RCC computing system”) and a reconfigurable computing hardware array (hereinafter “RCC hardware array”). In some embodiments, the target system and the external I/O devices are not necessary since they can be modeled in software. In other embodiments, the target system and the external I/O devices are actually coupled to the coverification system to obtain speed and use actual data, rather than simulated test bench data. The RCC computing system contains a CPU and memory for processing data for modeling the entire user design in software. The RCC computing system also contains clock logic (for clock edge detection and software clock generation), test bench processes for testing the user design, and device models for any I/O device that the user decides to model in software instead of using an actual physical I/O device. The user may decide to use actual I/O devices as well as modeled I/O devices in one debug session. The software clock is used as the external clock source for the target system and the external I/O devices to synchronize all data that is delivered between the coverification system and the external interface. The coverification system contains a control logic that provides traffic control between: (1) the RCC computing system and the RCC hardware array, and (2) the external interface (which are coupled to the target system and the external I/O devices) and the RCC hardware array. Because the RCC computing system has the model of the entire design in software, including that portion of the user design modeled in the RCC hardware array, the RCC computing system must also have access to all data that passes between the external interface and the RCC hardware array. The control logic ensures that the RCC computing system has access to these data. Pointers are used to latch data from the RCC computing system and the external interface to the internal nodes of the hardware model in the RCC hardware array. Pointers are also used to deliver data from the internal nodes of the hardware model to the RCC computing system and the external interface. Even if the data from the internal nodes of the hardware model is intended for the external interface, the RCC computing system must also be able to access this data as well.

Converification system and method

A method and apparatus for simulating custom chips to be used in a data processing system. Each chip is simulated by a chip simulator that includes a mother board and a plurality of baby boards mounted and interconnected on the mother board. Each baby board has circuit components mounted thereon for performing the circuit function of one cell of the chip. Chip simulators are interconnected in an interconnecting apparatus that supports the mother boards in parallel and spaced apart relation. Chip simulators that represent all of the chips found on a single printed circuit board in the system are interconnected at the interconnecting apparatus so that design errors which are only evident when the chips are interconnected can be tested for and detected prior to fabrication of the chips.

Gerald J. Erickson

Papers

Method for simulating and testing an integrated circuit chip