SLS, a large-capacity, high-performance switch-level simulator developed to run on an IBM System/370 architecture is described. SLS uses a model which closely reflects the behavior of MOS circuits. The high performance is the result of mixing a compiled model with the more traditional approach of event-driven simulation control, together with very efficient algorithms for evaluating the steady-state response of the circuit. SLS is used for design verification/checking applications and for estimating fault coverage.>

The High-Speed Simulator (HSS) is a fast and flexible system for gate-level fault simulation. Originally limited to combinational logic, it is being extended to handle sequential logic. It may also prove useful as a functional simulator. The speed of HSS is obtained by converting the cycle-free portions of a circuit into optimized machine code for a general-purpose computer. This compiled code simulates the circuit's response for 16 or 32 test patterns in parallel. Faults are injected into the circuit by changing the machine instruction corresponding to the fault location. From the range of speeds seen in recent measurements, we take 240 million gates per second as a fair general estimate of the speed of 2-valued simulation running on a 3081/K computer. For 3-valued simulation, divide by 2.9. The paper discusses the merits and drawbacks of the HSS strategy. It also sketches the extensions of HSS to model sequential logic and the various applications of HSS. These include functional verification, design for testability, good machine signatures, and accurate simulation of transistor-level defects in certain CMOS technologies. Finally, there is some discussion of how the simulation requirements of future designs can be met, and of the lessons to be drawn from long-term experimentation with HSS.

We describe SLS, a large capacity, high performance switch level simulator, developed to run on an IBM System/370 architecture, that uses a model which closely reflects the behavior of MOS circuits. This performance is the result of mixing a compiled model with the more traditional approach of event-driven simulation control, together with very efficient algorithms for evaluating the steady state response of the circuit. SLS is used for design verification/checking applications and for estimating fault coverage.

One has a shift register of length n and a collection of designated subsets of {0, 1,···, n-1}. The problem is to devise a method for feeding a string of bits into the shift register in such an order that, for each designated subset S = {k1,···, kr}, if one keeps track of the bit patterns appearing at the corresponding positions k1, ···, krof the shift register, all 2r possible bit patterns will ultimately appear at those positions. A simple and efficient solution to this problem, derived from the connections between polynomials over finite fields and linear feedback shift registers, is presented. Applications of this solution to the problem of VLSI self-testing are discussed and illustrated.

With the advent of VLSI, testing has become one of the most costly, complicated, and time consuming problems. The method of syndrome- testing is applicable toward VLSI testing since it does not require test generation and fault simulation. It can also be considered as a vehicle for self-testing. In order to employ syndrome-testing in VLSI, we electronically partition the chip into macros in test mode. The macros are then syndrome tested in sequence.