SU1310771A1 - Device for converting time intervals to digital code - Google Patents

Abstract

A device for converting time slots into a code contains a generator 1 of a reference frequency pulse, a scaling circuit 2, a multiplexer 3, a D-flip-flop 4, counters 5, 6, a code converter 7, groups 8, 9 of information outputs and an input bus 10. The invention allows to expand device functionality 1 il. ff (L with: s

Description

eleven

The invention relates to a pulse technique and can be used in digital measuring devices, as well as in the composition of the measuring and computing systems for measuring and recording time intervals.

The purpose of the invention is to expand: the functionality of the device.

The drawing shows a functional diagram of the device for converting time slots to code.

The device contains a generator of 1 pulses of the reference frequency, a scaling circuit 2, a multiplexer 3, D-flip-flop 4, the first counter 5, the second counter 6, a converter of 7 codes, the first 8 and second 9 groups of information outputs of the device and the input BUS 10.

The output of the generator 1 is connected to the first input of the scaling circuit 2, the second input of which is connected to the input bus 10 of the device, and the outputs i from 1 to t are connected respectively to the information inputs D to D of the multiplexer 3, the inverse output of which is connected to the inverse input setting D-flip-flop 4 to the zero state and the counting input of the counter 5, the inverse pre-installation input of which is connected to the inverse output of the B-flip-flop, 4, and the overflow output connected to the clock input of the D-flip-flop and counting input of the counter 6, information e outputs of which are connected to the data inputs of the converter 7 and the control outputs of the multiplexer 3.

The information D-input of D-flip-flop 4 is connected to the bus of the logical unit, and a code equivalent to the number of

N .Т, (1) where, is the capacity of the counter 5;

-y is the division ratio of the scaling circuit between outputs i-i and i. . . The information outputs of converter 7 are the first group of device outputs, and the information outputs of counter 5 are the second group of outputs.

The device works as follows.

The pulses of the highly stable reference frequency fj from the output of the generator 1 are fed to the clock input of the counting circuit 2, which is a series of meters connected in series — frequency dividers with a constant division factor –y, which work on subtraction.

In this case, the division factor from the input of the scaling circuit to the output is equal to p and from the output to the output is equal to y, where p is an integer chosen such that the number) / p is also an integer.

The division ratio between any outputs i-1 and i is also equal to v. At the outputs of the scaling circuit 2, a number of frequencies are formed that differ from one another by -Y times;

With the chosen coefficients de .- fat,: f f ... f h laziness f, -; fj jp--; f3 ru2

etc., i.e.

f. - ,./РТ (2) The output of multiplexer 3 receives a signal from that information input D Dm D of which, equivalent to the number Poc ,, is present on its control inputs and is determined by the contents of counter 6.

So, if the number whose code is stored in the counter 6 is 0 (ps, 0), then the multiplexer output pulses from the first output of the scaling circuit 2, if Pa, 1, then the output of the multiplexer 3 contains pulses from the second output of the scaling circuit 2, etc.

Thus, the relationship between the output number of the scaling circuit 2 connected to the counting input of the counter 5, and the number whose code is stored in the counter 6, has the form i n + 1. (3)

In this case, the dependence of the frequency of the pulses arriving at the counting input of counter 5 at different values of the code stored in counter 6, taking into account (3), has the form

t

(four)

and the period of the following pulses is respectively

T - 1-, s,

G. f3T

in the initial state on the input bus 10 of the device there is a logic one level, which prohibits the operation of the counters-dividers of the counting circuit 2, keeping them in the zero state. In this case, there are no pulses at the outputs of the scaling circuit 2.

When the zero time level of the converted time interval on the differential from one to zero arrives at the input bus 10, the zeroing circuit counters 5 and 6 (not shown) are zeroed.

In addition, the zero signal level at the second input of scaling circuit 2 allows the operation of counters-dividers.

Since the counters 5 and 6 are set to zero, i.e. the numbers are equivalent to the codes stored in the counters 5 and 6, respectively, are equal to П (and П.0.0, then the counter inputs of the multiplexer 3 begin to receive pulses

cfjt. ,

PL of the first exit of the

accounting circuit 2.

The pulses arriving at the counting input of counter 5 increase its content.

If the transformed time interval ends before the first overflow of counter 5 occurs, which is possible if TxT0, where i / f and jo P / f3T is the pulse following period from the multiplexer output with a zero code stored in counter 6, the digital equivalent of the converted time interval is equal to the number of pulses transmitted to the input of counter 6,

to the wife for the period of their following:

p Pr, -

If the converted time interval exceeds the time of filling the counter with 5 pulses from the first output of the counting circuit 2, i.e. TX 1 o MdKc T n the counter overflow 5 occurs and an output pulse is generated at its output overflow.

On this pulse, the contents of counter 6, i.e. n 1 1, and the output of multiplexer 3 is connected to the second output of scaling circuit 2, the frequency of the pulses at the output of which, on the basis of (4), is equal to

fST

ABOUT

five

0

five

0 5 0

50

five

 -h r. ;

In addition, the pulse of overflow of counter 5, D-trigger 4, is set to one, in which a signal is set at the input of the preset to write to counter 5 of a code equivalent to the value of the time interval from the start of the conversion to overflow of counter 5, reduced to new time scale.

The value of this number, No, is defined as the ratio of the time of filling the counter 5 before overflowing with pulses with a frequency determined by a code equivalent to the number of PCs at the output of counter 6 to the period of the pulses following the subsequent filling defined by the code at the output of counter 6 equivalent to the number Nn + 1, i.e.

 Pomax. Where Poms (ks -Tn / fjT) is the time to fill counter 5 with the code in counter 6 equivalent to the number n:

R.

Tpo + 1 b period of trace J et no pulse filling counter 5

with a counter code of 6, equivalent to the number n l + 1.

Since the capacitance of the counter is 5 Ps,;, ax and the frequency division factor of recalculation circuit 2 is constant, then for all overflows of counter 5, the code of the input number remains constant and equivalent to

Ng-

Thus, with each subsequent overflow of the counter 5, it is reset and followed by a pulse from the output of the D-flip-flop, entering into it a code of the number Ng. This code, at the current time scale value, defined by counter code 6, corresponds to the duration of the time interval for filling counter 5 from the start of the conversion to the moment of the previous overflow.

With such an organization of the conversion process, when the time interval covered before the moment of the overflow of counter 5, is learned as a result of the conversion by periodically writing the code of the constant number Nn into counter 5, one can imagine the result of the conversion in

five

 the code on the information outputs of counter 6, equivalent to the number that is contained in counter 5 at the time the conversion ends, equal to the sum of the number of pulses arriving at counter 5 after the overflow, and the number NO.

The result of the conversion is determined from the dependence

but

 .

t, n

about

By

  ET

Thus, the measured time interval is determined by the code at the information outputs of counter 5, equivalent to the number of pulses n, and the code at the information outputs of counter 6, equivalent to the number of pulses Pa and determining the time scale. Converter 7 is designed to convert the code number n

6 code convenient to use.

Claims (1)

The presentation of the conversion results in a form that is easy to read directly eliminates the need for a specialized calculator when using the device in measuring instruments, and the lack of time spent on calculating the digital equivalent works in real time. Invention Formula A device for converting time intervals into a code containing a pulse generator of the reference hour Editor A. Ogar Compiled by Yu.Shishkin Tehred L. Serdyukov and Proofreader M. Pojo Order 1888/43 Circulation 371Subscription VNIIPI USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushsk nab., D.A / 5 Production and printing company, Uzhgorod, Projecto st., 4 f5 The ports, whose code is connected to the first input of the scaling circuit, the first and second counters, the second counter's input is connected to the output of the overflow of the first counter, characterized in that, in order to extend the functionality, a multiplexer, a D-trigger and a converter are added to it 0 code reader, informational outputs: of which are the first group of device outputs, and informational inputs are connected to informational outputs of the second counter and multiplexer control inputs, informational inputs of which It is connected to the corresponding outputs of the scaling circuit, and the inverse output is connected to the counting input of the first counter and the inverse installation of the D-flip-flop in the zero state, the D-input of which is connected to the logical unit bus, and the clock input is connected to the overflow output of the first the counter, the inverse pre-recording input of which is connected to the inverse output of the D-flip-flop, the information inputs of the pre-recording of the first counter are connected to the pre-recording bus, and the information outputs of the first of the counter are a second group of information outputs of the device, with the input bus which is one with the second input of the scaling circuit 35.