Ando Electric Company

Toshiyuki Ohtaki

Mitsuru Kondo

Yu Sato

An IC measuring device constituted by a first timing generator (TG) for outputting a pair of judgment strobe pulses (S); a first edge detector (E) for detecting the states of a data strobe (DCK) at two time points within one test cycle on the basis of the pair of judgment strobe pulses (S); a second timing generator (TG) for outputting a pair of judgment strobe pulses (S); a second edge detector (E) for detecting the states of data at two time points within one test cycle on the basis of the pair of judgment strobe pulses (S); and a judgment section (J) for determining acceptance/rejection of the timing of the data with reference to the data strobe on the basis of the states of the data and the states of the data strobe.

IC measuring device

The object of the present invention is to offer a transmission line propagation delay time measuring device capable of reducing the measurement errors due to attenuation in transmission lines and allowing precise measurement of the transmission line propagation delay time. The invention comprises a test signal generating circuit 1 for generating a test signal for measuring the propagation delay time in a transmission line 3, a transmission line 3 having one end connected to the test signal generating circuit 1 via a measurement point at which the propagation delay time is measured and the other end open, a timing measuring circuit 5 for measuring the time required for the voltage at the measurement point 2 to reach a predetermined value, a data table 7 for storing transmission line attenuation values and measurement errors obtained by simulating the transmission line delay time measuring device as corrective data, and a computing circuit 6 for performing a propagation delay time corrective procedure by calculating a propagation delay time based on measurement values measured in the timing measuring circuit 5 and referring to the data table 7.

Device for measuring transmission delay time in a transmission cable

A propagation delay time measuring device has a test signal generating circuit, a time measuring circuit, a data table and a calculation circuit. The test signal generating circuit generates a test signal and supplies the test signal to a measuring point which is connected to one of the terminals of a signal transmission line. The time measuring circuit receives a signal waveform at the measuring point. The signal waveforms indicates an waveform of the test signal supplied to one of the terminals of the signal transmission line and a waveform reflected by another terminal of the signal transmission line and returned to the measuring point. The time measuring circuit measures a time when the test signal is supplied to the measuring point and a time when the reflected waveform is returned to the measuring point based on the signal waveform at the measuring point. The data table stores correct data made up of propagation delay time data and measurement error data which are obtained by a simulation of the signal transmission line. The calculation circuit calculates a propagation delay time of the signal transmission line based on the times measured by the time measuring circuit and corrects the calculated propagation delay time based on the data table.

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Tokyo, Japan

Toshiyuki Ohtaki