SU1355971A1 - Device for synchronizing reception of asynchronous signals - Google Patents

Abstract

The invention relates to the field of computer technology and can be used in automation and telemechanics for organizing the exchange of information between devices having autonomous clock generators. The aim of the invention is to increase reliability by eliminating metastable states of a trigger. The goal is achieved by introducing a pulse former 1. 2 Il. y S 00 SP SL M M fig. /

Description

The invention relates to computing and can be used in automatic and telemechanics for organizing the exchange of information between devices having autonomous clock generators.

The aim of the invention is to increase reliability by eliminating metastable trigger conditions.

Figure 1 shows the diagram of the device; figure 2 - timing charts of the device.

The device contains a driver 1 pulses, triggers 2 and 3, the input 4 of the asynchronous signal, the synchronous input 5, the output 6 of the driver 1, the output 7 of the trigger 2, the output 8 of the device.

The device works as follows.

 When an asynchronous signal arrives at input 4 of the device, driver 1 generates pulses (signals 6, figure 2) for each difference of input signals. Pulse duration at the output of the imager is selected

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the largest of the t and f, f values where t cr is the time for setting the information} n m as the minimum allowable pause time between the sync pulses for trigger 3. Under the action of signals from shaper 1, trigger 2 is set to zero (signal 7, fig .2). After the pulse of the driver 1 is terminated, the trigger 2 switches to the one state on the leading edge of the clock signals (signal 4, Fig. 2). Trigger 3 switches (signal 8, FIG. 2)

25 mA of asynchronous signals containing two triggers, the synchronized input of the first trigger being the synchronous input of the device, the second trigger indicating the output of the device, which is so that, in order to increase the reliability due to the elimination of metastable states of the trigger, a pulse shaper is inserted into the device the information input of the second trigger is connected to the input of the pulse generator and is the input of the asynchronous signal of the device; the output of the pulse generator is connected to the reset input

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to the state corresponding to the input 40 zero of the first trigger, the information signal, on the leading edge of which the pulse input is connected to the bus from the output of the trigger 2. unit potential of the device,

The device eliminates the metastas. The output of the first trigger is connected to the main conditions on the trigger code by the synchronous input of the second trigger.

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VNIIPI Order 5794/42 Circulation 671 Subscription Proizv.-po ot.pr-tie, Uzhgorod, st. Project, 4

3, since the arrival of the clock difference to the synchronous input of the trigger 3 is prohibited for a time greater than the time required for establishing information at its information input. The hold time requirements are also satisfied, since the duration of the sync signal is long enough. The signal from the driver 1 output is fed to the reset input to zero of the trigger 2, which operates independently of the clock pulses. Any time relationships between the sync pulses and the pulses of the installation are permissible and not limited.

As a shaper 1, an EXCLUSIVE OR element can be used, for example, K531LP5, to one input of which the input signal goes directly and to the other through a delay element.

Claims (1)

Apparatus of the Invention A device for synchronizing the reception of asynchronous signals containing two flip-flops, the synchro-input of the first flip-flop being the sync-input of the device, the second flip-flop being the output of the device, differing from the fact that pulse generator, where the information input of the second trigger is connected to the input of the pulse generator and is the input of the asynchronous signal of the device, the output of the pulse generator lsov connected to the reset input 0US.2