Abstract: A method identifies the cause of poor correlation between an integrated circuit model and measured integrated circuit performance. The method includes determining the propagation delays through two separate integrated circuit components. The propagation delays are then compared to each other to identify the cause of the poor correlation.

Abstract: VLSI I/O structures to reduce the effects of simultaneous switching noise (SSN) on output driver circuits and enhance electrostatic discharge immunity, while reducing chip area, in both input receiver circuits and output driver circuits include improved transistors having deep-junction drain and a multi-cascaded, resistive deep-junction source structure.

Abstract: A clock bus system fabricated on an integrated circuit for distributing a train of clock pulses to circuit elements on the integrated circuit. An input terminal is connected to receive a train of clock pulses. All of the circuit elements are circumscribed by a clock bus which is also coupled to each of the circuit elements. A plurality of distribution legs which include clock bus drivers are coupled to the input terminal by conductors and provide the train of clock pulses to the clock bus at spaced-apart locations. The distribution legs coupled to the input terminal by shorter conductors include delay elements for delaying the clock pulse train by time periods corresponding to the delay inherent in longer conductors. The clock pulse trains provided to the clock bus by the distribution legs are thereby synchronized with respect to each other.

Abstract: An integrated circuit with temperature compensated output buffers which are adapted for impedance matched coupling to transmission lines when operated at either room temperature or at a cryogenic temperature (e.g., immersed in liquid nitrogen). The output buffers include output terminals which are adapted to be coupled to the transmission lines. Output stages of the output buffers have an output impedance which is less than a characteristic impedance of the transmission lines, and are characterized by a temperature coefficient of resistance. Compensation resistors which have an impedance less than the characteristic impedance of the transmission lines, and are characterized by a relatively low temperature coefficient of resistance, couple the output stages to the output terminals.

Abstract: An improved built-in self-test system fabricated on an LSI circuit chip for performing dynamic tests of main logic function operation. The built-in self-test system includes a control register comprising a series of static flip-flops connected for serial test data transfer and for producing test system control signals. An input shift register connected for serial test data transfer with the control register and for parallel test data transfer with the main logic function is formed by a series arrangement of static flip-flops. An output register connected for serial test data transfer with the input register, and for parallel test data transfer with the main logic function, is formed by a series arrangement of static flip-flops. A test clock enable signal is latched by a test clock enable latch, and gated with a system clock signal to produce input and output register clock signals. A test strobe signal is latched by a test strobe latch and strobed by a flip-flop for use as a control register enable signal.