Hiroyuki Michinishi

A test methodology for interconnect structures of LUT-based FPGAs

In this paper we consider testing for programmable interconnect structures of look-up table based FPGAs. The interconnect structure considered in the paper consists of interconnecting wires and programmable points (switches) to join them. As fault models, stuck-at faults of the wires, and extra-device faults and missing-device faults of the programmable points are considered. We heuristically derive test procedures for the faults and then show their validness and complexity.

Universal test complexity of field-programmable gate arrays

A field-programmable gate array (FPGA) can implement arbitrary logic circuits in the field. In this paper we consider universal test such that when applied to an unprogrammed FPGA, it ensures that all the corresponding programmed logic circuits on the FPGA are fault-free. We focus on testing for look-up tables in FPGAs, and present two types of programming schemes; sequential loading and random access loading. Then we show test procedures for the FPGAs with these programming schemes and their test complexities. In order to make the test complexity for FPGAs independent of the array size of the FPGAs, we propose a programming scheme called block-sliced loading, which makes FPGAs C-testable.

Testing for the programming circuit of LUT-based FPGAs

The programming circuit of look-up table based FPGAs consists of two shift registers, a control circuit and a configuration memory (SRAM) cell array. Because the configuration memory cell array can be easily tested by conventional test methods for RAMs, we focus on testing for the shift registers. We show that the testing can be done by using only the faculties of the programming circuit, without using additional hardware.

CMOS floating gate defect detection using I/sub DDQ/ test with DC power supply superposed by AC component

In this paper, we propose a new I/sub DDQ/ test method for detecting floating gate defects in CMOS ICs. In the method, an unusual increase of the supply current, caused by defects, is promoted by superposing an AC component on the DC power supply. The feasibility of the test is examined by some experiments on four DUTs with an intentionally caused defect. The results showed that our method could detect clearly all the defects, one of which may be detected by neither any functional logic test nor any conventional I/sub DDQ/ test.

Precise Measurement System for Knee Joint Motions at Pendulum Test Using Accelerometer – Detection of Angular Acceleration by Two Linear Accelerometers–

Pendulum test had been used for trial diagnoses of spastic human subjects. The angle e of knee joint had been measured with a potentiometer and the first and second order derivatives of θ had been used for obtaining of angular velocity and angular acceleration, respectively. It was not easy however to hold the position of the potentiometer stable and even if the position slightly shifted, a large error might occur in the detected signal. Furthermore, the differential process trended to accompany a big noise. Then we developed a new method to measure the knee joint motions by the use of some accelerometer. The accelerometer could be attached to a lower leg easily and stably. If only one accelerometer was used however, both of knee joint angular velocity and knee joint angle calculated by integration might be accompanied with a large error, because it was under the influence of gravity. In order to overcome the difficulty, a measurement system for knee joint motions was constructed with a couple of accelerometers in this study. The accurate angular acceleration could be calculated as the difference between two output values of the accelerometers. The angular accelerations, angular velocities and angles in knee joint motions of normal subjects and spastic subjects were measured by the use of this system and it was shown that the error originated to the gravity decreased drastically comparing with the case of the only one accelerometer. This system would be useful for diagnosis of spastic patients by the use of pendulum test and for parameter decisions of the biomechanical and neural knee joint model.

Minimum verification test set for combinational circuit

A sufficient condition under which a minimum verification test set (MVTS) for a combinational circuit has 2/sup w/ elements is derived, where w is the maximum number of inputs on which any output depends, and an algorithm to find an NVTS with 2/sup w/ elements for any CUT with up to four outputs is described.<<ETX>>

Precise Measurement System for Knee Joint Motion During the Pendulum Test Using Two Linear Accelerometers

The pendulum test is a means to evaluate the knee joint reflex from the pendulum motion induced by letting the lower leg drop freely after it has been lifted up (Watenberg, 1951). Many researchers have attempted to quantify the spinal cord stretch reflex from this pendulum motion in order to diagnose spasticity (Fowler et al., 2000; Kaeser et al., 1998; Lin & Rymer, 1991; Nordmark & Andersson, 2002; Stillman & McMeeken, 1995; Vodovnik et al., 1984). However, even today, much remains unknown about the relationship between this pendulum motion and the mechanism that produces the stretch reflex. For this reason, quantification studies on the stretch reflex have progressed slowly.

A Detailed Model for Knee Joint Acceleration Motions Obtained by Pendulum Test

This paper describes a detailed model (pendulum test model) to be able to utilize for simulations of knee joint motions obtained by pendulum test. First, we construct a simple pendulum test model based on existing organ models and clarify from the simulation results by the use of the model that there exist two difficulties impairing its accuracy. Next, in order to overcome them, we add two functions to some of the organ models in the simple pendulum test model. One is a function that the muscle viscosity in the muscle model changes nonlinearly according to dynamic state transition of actin/ myosin. The other is a function that the threshold value of the firing in the α-motoneuron model slightly decreases in the early stage of the pendulum test by the amount proportional to the total of the first burst firing. Finally, we confirm from simulations of knee joint motions measured experimentally that the improved pendulum test model has an excellent performance of accuracy. The model will be very useful for estimation of spasticity.

Detection of CMOS Open Node Defects by Frequency Analysis

A method to detect open node defects that cannot be detected by the conventional IDDQ test method has previously been proposed employing a sinusoidal wave superposed on the DC supply voltage. The present paper proposes a strategy to improve the detectability of the test method by means of frequency analysis of the supply current. In this strategy, defects are detected by determining whether secondary harmonics of the sinusoidal wave exist in the supply current. The effectiveness of the method is confirmed by experiments on two CMOS NAND gate packages (SSIs).

Minimum test sets for locally exhaustive testing of combinational circuits with five outputs

In this paper, features of dependence matrices of combinational circuits with five outputs are discussed, and it is shown that a minimum test set for locally exhaustive testing of such circuits always has 2/sup w/ test patterns, where w is the maximum number of inputs on which any output depends.<<ETX>>