CS242760B1 - A method of measuring the length of a time interval using a tag analyzer - Google Patents

Abstract

The subject of the invention relates to the field of drivers and measurement technology and solves the problem of measuring the length of a time interval using a symptom analyzer. The measurement method according to the invention simplifies the sensing of a characteristic symptom by connecting only two inputs of the symptom analyzer to the measured circuit, CP and a data probe, which is used to sense the START and STOP signals. When measuring at multiple points of the circuit, it is sufficient to move only the tip of the data probe. The choice of functional edges of all control signals remains preserved. The characteristic symptom uniquely determines the length of the time interval at the controlled point. The invention is used when measuring the length of time intervals in digital circuits, especially when locating faults.

Description

The invention relates to a method for measuring the length of time intervals in electrical circuits by means of a feature analyzer.

Until now, the measurement of time intervals in electrical circuits has been performed either with a counter or with an oscilloscope. This measurement required the use of special instruments. In circuits that can work synchronously and for which the test for the control of the feature analysis is designed, the feature analyzer can also be used to measure the length of time intervals.

The time interval can be measured by measuring a characteristic feature at a controlled measuring point. Characteristic flag sensing assumes the following flag analyzer connection:

- connection of CP synchronization signal,

- connection of START signal for triggering of measured interval,

- connection of the STOP signal for the end of the measured interval,

- connection of data probe to log 1 level, ie connection of four control signals.

When measuring at multiple points of the circuit, it is necessary to move both signals START and STOP, while moving the measuring points or connecting hooks between the terminals of integrated circuits then undesirable bridging, which may result in impairment of the current measurement, or in extreme cases, destruction of the measured circuit.

The above-mentioned disadvantages of the current state are eliminated by the method of measuring the time interval by means of a flag analyzer according to the invention, which consists in that synchronous pulses are connected to a known frequency to the measured circuit by the flag analyzer input. a data probe corresponding to log 1 level on the data probe is automatically fed to the input of the pseudo-random generator of the flag analyzer binary sequences, while the choice of the functional edges of the control signals is retained.

The method of measuring the length of the time interval according to the invention simplifies sensing the characteristic feature and thus the length of the time interval. When measuring in multiple points of the circuit, it is sufficient to move only the tip of the data probe, while measuring in a known way it is necessary to reposition the START and STOP signal hooks and keep the data probe at log 1 level, or use special instruments such as a counter or oscilloscope. In comparison with the present method, the measurement according to the invention is reduced by more than half and leads to an acceleration of the fault location in the circuit under measurement.

As an example of the use of the method of measuring the time interval according to the invention, a fault location of the binary counter is given. Attached is a block diagram of a 12-bit binary counter and how to connect a flag analyzer. The outputs of the individual flip-flop counters show the actual characteristics. The analyzer is connected by CP synchronization input to the counter clock pulse input. The START and STOP inputs of the event analyzer are not used because the START and STOP signals for the measurement interval boundary are taken from the measured outputs - Q _{12 by a} data probe. This speeds up and simplifies the measurement procedure.

The fault location is performed by gradually checking the characteristic symptoms, starting from the output towards the output Qj. The fault is between the last wrong and the first correct symptom.

An example of the use of the method of measuring the time interval according to the invention is shown in FIG.

The meaning of the blocks in Fig. 1.

- first four-bit linear counter

- second four-bit linear counter

- third four-bit linear counter

- data acquisition probe

- flag analyzer

The fault location procedure is as follows:

The sync input of the tag analyzer CP is connected to the CP input of the first counter 1. · The START and STOP inputs of the tag analyzer are not connected and the START and STOP signals for the measurement interval boundary are taken from the measured circuit by data probe _4.

The data probe 4 is used to gradually check the characteristic flags at the outputs Qy of the counters 1, 2, 2. Thus, the measurement is accelerated, since only the tip of the data probe i needs to be moved. linear counter. The fault is between the last wrong and the first correct symptom.

Claims (1)

OBJECT OF THE INVENTION A method of measuring the time interval by means of a flag analyzer, characterized in that the synchronization pulses are connected to a known frequency to the measured circuit by the flag analyzer input CP and the START and STOP signals intended for bounding the measured interval are sensed by a data probe and the analyzer is automatically supplied with a level corresponding to the log 1 level on the data probe, while the selection of the functional edges of the control signals remains unchanged.