SU1552138A1 - Method of checking technical condition of digital units - Google Patents

Abstract

The invention relates to computing and can be used, in particular, in the course of its operation and in the process of conducting input control of a digital element base, as well as in the manufacture of digital systems. The purpose of the invention is to increase the reliability of determining the technical condition of digital blocks. The monitored digital block 2 is supplied with voltage from power supply 1 and test actions from a pseudo-random sequence generator 10 controlled by a 9-clock pulse generator. The current pulse extracting unit 3 provides for the separation of high-frequency pulses appearing in the power supply during operation of the digital unit 2. These pulses are amplified by the wideband amplifier 4, processed by the comparator 5 and the trigger 6. The correlator 7 forms the impulse response of the digital unit 2, which serves as an informative parameter and is output for comparison with the standard on display unit 8. 4 il.

Description

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The invention relates to computing technology and can be used., In particular, during its operation and in the process of conducting input control of a digital element base, as well as in the manufacture of digital systems.

The purpose of the invention is to increase the reliability of control of the technical unit of digital blocks.

Figure 1 shows an e5lock diagram of a device for implementing the method; 2 shows diagrams for the operation of the device; Fig. 3 is a block diagram of a monitor.

The method is based on the application of Moore's theory, with which one can calculate with a sufficient degree of accuracy, limited only by the noise of measuring instruments, the impulse response for an arbitrary kinetic model using the characteristics of an input given test signal of Luba, the system is also nonlinear, taking into account the linearization method operating point neighborhood is described by impulse response.

The digital block transient determines the change of not one, but the totality of parameters characterizing the digital block. It is known that such a process is the most informative and can increase the value of control of digital blocks. This is due to the fact that the transition process is a dynamic mode of operation of the diagnosed

It is known that the response of a linear sieteme to any input effect of an op-30 Digital block, in which the most

determined by the integral complete, the true level of its technical state appears. A characteristic impulse is an individual function of the technical status of a digital unit in the sense of uniting in itself the totality of the values of individual parameters characterizing the technical state of a digital unit, with its help it is possible to assess its degree of efficiency.

about

 h (t C) x (1) dC.

(1) symbolically, semi

x (t) h (t),

(ABOUT

(2)

where y (t) is the reaction of the linear system

on input impact; x (t) is the input action; t is time;

With an integration parameter; h (t) - impulse response

linear system. Let R (C) be the autocorrelation function of the input (signal) x (t) input;

Kich. (C) cross-correlation

to the function of the input and output signals "These functions are connected by the same convolution equation (2) as the signal

(C) h (O. (3)

R,

, ()

 X, V V / X, x

If RXX (C) is replaced by the Dirac functions Γ (Ј), then from the definition of the impulse response of a linear system, as a reaction to the function of this system

expression (3) is reduced to vi, y

(C) f () h (C) h ().

(four)

themes d

So, if the autocorrelation function of the input signal behaves like the (/ function, then the mutual correlation function of the input and output signals is the impulse response of the linear system. This method of determining the impulse response applies to nonlinear systems (digital blocks) and makes it possible to measure them dynamic characteristics at the operating point. The impulse response is the result of a digital block transient analysis.

The transient of a digital block determines the change not of one, but of a set of parameters characterizing a digital block. It is known that such a process is the most informative and can increase the reliability of control of digital blocks. This is due to the fact that the transition process is a dynamic mode of operation of the diagnosed

The digital unit in which the most

the true level of its technical condition appears. The impulse response is an individual function of the technical state of a digital unit in the sense of combining the totality of the values of individual parameters characterizing the technical state of a digital unit, with its help it is possible to assess the degree of its performance.

w tJL.

" one

(five)

where W is the degree of performance

digital block; LM is the normalized value of the impulse response of the digital unit. The impulse response of a digital unit over a power circuit is defined as the mutual correlation function of the input test signal of a digital unit and the output signal of the power supply circuit, which is a response in the form of high-frequency current pulses for switching elements of a digital unit to an input. Given the input effect such that its auto-correlate 5155

The function was (/ -function, using for this purpose a pseudo-random sequence, which is easy to implement using a shift register, and the correlator connected to the power supply circuit measures the impulse response of the digital unit through the power supply circuit. In the general case, the impulse response across the pi circuit - A digital block with a faulty element is different from the impulse response over the power circuit of a healthy digital block. The impulse response over the power circuit of a digital block is defined as integral (1), Achen is received by the correlator on a finite interval measurement is the impulse response of the power circuit, which allows to evaluate the technical state of the digital unit. For controlled digital block is performed Conditions

h

t

Ah

one

(6)

 "

where h x (t) y () dt is the value

about impulse response across the circuit

digital power supply;

x (t) is the input signal in the form of a pseudo-random sequence voltage;

y (t) is the output signal in the power supply circuit in the form of pulses of switching voltage of elements as a result of the action of a voltage of a pseudo-random sequence at the inputs of the digital-to-unit;

T is the integration time equal to the length of the pseudo-random sequence;

h3 is the reference value of the impulse response across the power supply circuit of an operational digital blockj

LLE is the standard deviation of the impulse response from Le, obtained on the basis of statistical processing of the measurement results on previously operable digital blocks. Failure to comply with condition (6) indicates a malfunction of the digital unit. The measurement of the impulse response over the power supply circuit of the digital unit is performed in the following sequence. The information inputs of the digital unit are fed with an input action in the form of a pseudo-random sequence (PSP), in the power supply circuit due to the operation of elements

86

The effect is high-frequency current pulses exceeding the level of the fluctuating Hauk. These high frequency pulses are extracted and converted into voltage pulses, amplified and fed to a correlator, which measures the mutual correlation function of these pulses and the input action. This cross-correlation function is the impulse response across the power supply circuit of the digital unit.

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A device for implementing a method for controlling a technical state of a digital unit (Fig. 1) contains a power supply unit 1, a digital unit 2, a current pulse extraction unit 3, a wideband amplifier 4, a comparator 5, a trigger 6, a correlator 7, an indication unit 8, a generator 9 clock pulses, the generator PSP 10. Moreover, the output of power supply unit 1 supplying digital unit 2 is connected to the input of current extractor unit 3, the output of which is connected to the input of broadband amplifier 4, the output of which is connected to the input of comparator 5, the output of which is connected to inputrigger 6 whose output is connected to the second input of the correlator 7, whose output is connected to the first input of the indication unit 8. Generator output 9 clock pulses are connected to the second input (synchronization clock) of the display unit 8 and to the input of the PSP generator 10, the output of which is connected to the information inputs 2.1-2.M of the digital block 2 and to the first input of the correlator 7.

A device for implementing the method of controlling the technical state of digital blocks works as follows

The generator 9 clock pulses produces a sequence of pulses. co-voltages with a clock frequency of up to 10 MHz (Fig. 2a), which are fed to the input of the PSP generator 10 to produce PSP voltage pulses (Fig. 26). PSP voltage pulses go to all information inputs of digital block 2, under the influence of which in its power supply circuit, current pulses (Fig. 2c) from switching elements are formed as a reaction to the input action. Current Pulse Isolation Unit 3 and Broadband Amplifier 4 You

715

these current pulses are divided, transformed into voltage pulses and amplified to the required value (fig. 2d, d). The comparator 5t, to the input of which voltage pulses are output from the output of broadband amplifier 4, normalizes them in amplitude (fig. 2e). From the output of the comparator 5, the pulses are fed to the counting input of the trigger 6f which converts this random sequence of voltage pulses to the memory band (fig.2g) 8 arriving at the information inputs of the digital unit 2. From the generator output of the memory bandwidth 10, memory bandwidth pulses ( Fig. 2b) is also received at the first input of the correlator of the torus 7, to the second input of which voltage pulses come from the output of the trigger 6 Sfig 2G). The correlator 7 measures the mutual correlation function of two input signals (fig. 2b, g) which is the impulse response across the power supply circuit of the digital block 2. The display unit 8 uses the clock pulses (fig. 2a) of the clock generator 9 to register on the screen (cathode ray tube) a stable image of the impulse response along the power circuit of the digital unit 2 (Figures 2 and 3). Comparing the measured value of the impulse response over the power supply circuit of the digital unit 2 with the reference

the value depicted on the template is determined by the degree of their compliance with the technical state of the digital unit (Fig. 02). In the proposed device for implementing the method of monitoring the technical condition of the digital units, the current pulse extraction unit 3 and the broadband amplifier 4, whose circuits are shown in FIG. structurally implemented and shielded in a single package. The block 3 for the selection of current pulses is implemented on a long line, which is a piece of Shorted at the end of a coaxial cable.

In block 3, the current pulse extraction uses the forming properties of the inconsistent line. Comparator 5 is a comparator without hysteresis. IK-trigger is used as trigger 6. The correlator with the first and second inputs 7 "1 and 7" 2 (Fig. 3) is built according to the parallel correlator circuit and contains K dis8

five

0

0

five

F r are often partial delay lines (11.1, 11.2, I POS, 11 "K), each of which is implemented on coaxial segments: cable0. The delay discreteness is 10 not, which is selected from

conditions AC uDe 1 U- g t

that clock number of multipliers, 12 (see block diagram of the correlator

7 in FIG. 3) is equal to the number of samples of the mutual correlation function. The integrators 13.1-13.IO1 are made on RC chains, the values of R, C are chosen based on the required integration time, determined by the length of the memory bandwidth. Adder 14 is assembled according to the parallel adder scheme.

8, the display unit 8 (FIG. 1) uses an oscilloscope C1-99. The oscillator 9 clock pulses (FIG. 1) is designed according to a quartz oscillator circuit on logic elements. The generator PSP 10 (Fig. 1) is constructed according to the scheme of the generator PSP with controlled delay,

The effectiveness of the technical condition monitoring method can be illustrated by analyzing the application of the method to the diagnostics of one logical element. The logical elements are characterized by two stable states. At the moment of transition from one state to another, i.e. at 5 moment of switching the circuit, its operation is described by the differential equation

d4U dt

2 JdU

C / K1 -K2-7 dt

(7)

where Kl, K2 are transmission coefficients from the 1st arm to the 2nd and 2nd to the 1st, respectively, U is the voltage;

The time constant of the control circuit;

. From analysis of expression (7) it follows that for normal functioning, tse. The provision of circuit switching requires that the condition be met. K1-K2 - 1 0. (eight)

The condition of technical good condition is written as

And K1 - K2 -1 / Ammm. (9) For transistor circuits, Kl, K2 are equal

about + 7,

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K2

LzKna „

t + 7e, / Сгг1 + r Т)

where r

Pi i TGI

R

KG1, R,

GB GB B2

 ge

R urt respectively

P

Tbz lvn n

e 1 s t n 1 gains, parameters

transistors, base resistance, emitter resistance, load resistance. The value of A is a characteristic of the generalized parameter, as can be seen from the expression (U). However, due to the fact that the processes occurring inside the element do not allow direct control of the value of A, the value of A can be indirectly determined using the impulse response across the power supply circuit, which is associated with the K1 and K2 Fourier transforms. Impulse response on the power supply circuit of a digital unit, being an individual function of a technical state, summarizing several parameters (10), from an information point of view, it allows to remove the uncertainty of the state of the monitored unit, which quantitatively kterizatsiya entropy of this state. Let the coordinates (S 1,2,3, ..,,) of the state vector be independent quantities. Then, using the well-known property, which consists in the fact that the entropy of a set of independent quantities is equal to the sum of the entropies of these quantities, we can write

Ht H5 (). (eleven)

2-

where H - is the entropy state of the digital blockade being diagnosed Hs () -entropy S-ro parameter, The amount of information carried by the parameter about the technical state of the digital block can be estimated by the expression

 S0)

k "

H,

loglY2fT.e & Ј.

(12)

Where

S

- dispersion of the parameter. In the case of application for estimating the technical condition of a digital unit, the impulse response over the power supply, which is a value that summarizes several parameters, including infra-low-frequency noise (parameters of transistor 10))

get the entropy of impulse response

(YU)

 W

S

lpgl / 21Te (

r + ...

+ PE

(13)

Where

Vfi

.. about p

- dispersion of the impulse response;

dispersion of parameters, generalized by impulse response.

Hh lost y2f & i

-.nn iH r T «« n

5 (h)

log, VZff6 Y

(14)

i ° s JjzlLzS. il + .K LLЈ - Ј iogi75t & | ix

Expression (14) shows that the reliability of the technical condition of the digital unit is obtained by comparing with the reference value of the impulse response across the power supply, in contrast to the prototype, which compares the infra-low level fluctuations of the power supply current of the digital unit,

increased in

..e & 31, Ј -gpJL log2

S, V

times Fore

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The method of controlling the technical state of digital blocks, which implies that a nominal supply voltage and an impulse input test effect are applied to the monitored digital block, determine the output response of the monitored digital block and compare it with the reference one, judging by the results of the comparison of the technical condition controlled digital block, distinguished by the fact that, in order to increase the reliability of monitoring the technical condition of digital blocks, the power supply pulses of the digital block and convert them into voltage pulses, amplify voltage pulses and determine the mutual correlation function of the pulse input test effect and voltage pulses, take the mutual correlation function as an output response of the monitored digital block, j

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Compiled by V.Stepankin Editor V. Bugrenkova Tehred L. Corrector N.Revska

Order 329

Circulation 560

VINILI of the State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035 „Moscow, Zh-35, Raushsk nab., 4/5

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Claims (1)

Claim A method for monitoring the technical condition of digital blocks, which consists in the fact that the controlled digital block is supplied with a rated supply voltage and a pulse input test effect, the output response of the controlled digital block is determined and compared with the reference one, judged by the results of comparison about the technical condition of the controlled digital block ^, It is characterized by the fact that, in order to increase the reliability of monitoring the technical condition of digital blocks, power pulses of the controlled digital eye and convert them into voltage pulses, amplify the voltage pulses determine the cross-correlation function of the input test pulse and impact of a voltage pulse, taking cross-correlation function as output of the digital controlled reaction block, j .ipschtlpldplsh SG ~ T TLI ----- L P 1 E /. . t .............. j t JL.JUIUJI / IL ... L_LL < JL-JUIIUUM ILJUL 1 1 — ui ~ 1P ... P — ΓΊ 3 ' A-,.· and _r j .Fae. Z