SU1564639A1 - Device for connection of subscribers to common trunk line - Google Patents

Abstract

The invention relates to computing and can be used in multi-machine computing systems. The purpose of the invention is to improve the performance of information transmission over a common highway. The device contains counters 1-3, triggers 4-7, elements AND 8 and 9, elements OR 11 and 10 and the main transceiver amplifier 12. The request from the subscriber to capture the common highway arrives at the input 14. At the entrance 13 the subscriber releases the common highway. Counter 1 is needed to set the priority for subscribers. The first to capture a common line 18 after being released by its current subscriber, the subscriber having the highest priority among subscribers who have requested to seize the highway. Trigger 6 is a status indicator for the trunk. 1 il.

Description

The invention relates to computing technology and can be used in multi-computer computing systems and local networks for connecting several subscribers to a common backbone.

The purpose of the invention is to improve the performance of the transmitted information on the common highway.

The drawing shows the functional diagram of the device

The device contains sweepers 1 - 3, triggers 4-7, elements AND 8 and 9, elements OR 10 and 11, trunk transceiver amplifier 12, first and second inputs 13, 14 channels, input 15 of the priority code, synchronization input 16, confirmation output 17 capture, common line 18, setup input 19, serial information input 205 sync input 21 tracking bits, clock output 22, information output 23.

The device works as follows.

The device is intended for decentralized arbitration of subscriber requests (computers) on the common railways, i.e. resolving common line capture conflicts on requests from several subscribers, when transmitting a bipolar code through a serial common highway returning to zero along lines with transformer links.

The request for seizure of the subscriber line enters the trigger 4 of its channel by giving a signal to the input 14 (in this case, the trigger 4 enters 1, in the absence of a request in the trigger 4 - O). After transmitting the data packet, the subscriber zeroed the trigger 4, giving a signal to input 13, Trigger 6 is intended to display the common trunk occupation: in the state O of the trigger, the trunk is occupied, and in state 1 it is free.

In the state O of the trigger 6, the counter 1 is set up according to the priority code from the input 15 (the code is specified hard), and the numbers recorded in the counters 1 of the different channels are different from each other. For example, the number A 1 can be recorded in the counter of the first channel, A 2 in the counter of the second channel, etc., where A is the counter conversion factor 1. When

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On the flip-flop 6, the operation of the counters 1 in the counting mode is blocked. At state 1 of trigger 6 (when the trunk is free), the installation signal of counters 1 is removed and they go into counting mode, in which the incrementing of the contents of counter 1 occurs on every clock pulse from input 16, the transfer signals of counters 1 of different channels are formed at different points in time , as when installing from the inputs 15 they contain various codes. If the Kth channel does not contain a request to capture the trunk (in the 4 O trigger), then when forming the transfer from the 1 record 1 record to the 5 trigger of this channel, as in the O state of the 4 trigger, the level 5 is applied to the trigger 5 input. blocking recording by D-input during the arrival of the transfer signal of counter 1 to the C input of the trigger 5. If the Kth subscriber made a request to acquire the trunk, i.e. In trigger 4, 1 is recorded, then the zero signal at the R input of trigger 5 is absent, and the skew signal from counter 1 is received. A trigger 5 is applied to the C input, 1 is written to it (the level 1 is permanently set to the D input of trigger 5). In the state 1 of trigger 4 and the generation of the transfer signal of the counter 1 fed to the clock input T of amplifier 12 is transmitted to the trunk the signal transmitted to the output of the TL 23, producing at state I of the trigger 6, produces a signal at the output of the element I 9, which enters the C input of the trigger 6, and writes O into it (the line is captured). When writing O to the trigger 6, the counter 1 is reset to the initial state (code entry from input 15) and the counting mode is locked. When writing 1 to trigger 5, output i7 is signaled to confirm that the common highway has been captured by the Km subscriber. As a result of the procedure described for decentralized arbitration, the common trunk is provided to only one of the subscribers who have claimed to seize the highway.

- With a free common highway, i.e. in the case of the single state of the trigger 6, through the element OR 11, the trigger 7 is set to O and the operation of the C input of the trigger 7 is blocked. In the zero state of the trigger 7, the input of the installation of the counters 2 and 3 receives a signal (level) that blocks their counting mode. When the flip-flop B is moved to the state O and when the common trunk is captured, the signals from the trunk 18 and the output 23 of the amplifier 12 are blocked through the AND 9 element, and the setup level is removed from the R input of the trigger 7, resulting in a signal passing through the trunk 18 and the appearance of the pulse at the output 23 of the amplifier, the trigger 7 is set to state 1. The information (data) is transmitted through the common line in words. The bits of the transmitted word are fed to the input 20, and the signals of the accompaniment are fed to the input 21 "At the transmission of each word, output 23 of the tracking pulses is restored, output 22 - the transmitted bits of the word and the first pulse of the packet from output 23 trigger 7

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the counter setting signal 2 and 3 is removed and their counting mode is unlocked. For each pulse from output 23, counters 2 are set and the contents of counters 3 increase by 1. At the completion of the transmission of the information word, i.e. bursts of pulses of the output 23, the number of clock pulses is equal to the number of bits of the transmitted word, and since for each impulse the counter 2 is reset (setting of the counter 2), the transfer signal of the counter 2 is not generated. The last impulse of the stack involves the formation of transfer of the counter 3, according to which the trigger 7 is set to the state O, and the counters 2 and 3 are reset. When transmitting the next batch of pulses (the next data word), the first pulse at the output 23 triggers the trigger 7 to state 1, the last pulse of the burst by transferring the counter 3 triggers 7 to the state O. During the transfer of the word through the trunk 18 and recovery of the pulse packet at the output 23 of the formation of the transfer of the counter 2 does not occur. Upon completion of the packet transmission, the subscriber who captures the common trunk exposes a signal to input 13 to release it, and through the element OR 10 and the trunk amplifier 12 to the trunk 18 is outputted single

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A single pulse is restored at output 23, and the trigger 7 is set to state 1 (via the C input), as a result of which the counting mode of the counters 2, 3 is unlocked. Since no pulse bursts are generated at the output 23, no pulses are received at the counting input of counter 3 and the zeroing input of counter 2, with the result that a transfer pulse is generated at the transfer output of counter 2, and no transfer signal is generated at the counter 3.

The transfer signal of counter 2 is set to 1 trigger 6, i.e. On all channels, the status of the common trunk is free. In this case, all the channels remove the installation level to the initial state of the counters 1, which switch to the counting mode, and the mode of arbitration of subscriber requests to seize the trunk is realized.

During the initial setup, the R-input of the flip-flops 6 and the counters 3 of all channels are given a signal that is used to display the occupancy of the highway in all channels and the initial installation of the counters 1 is made. Then one of the subscribers sends a signal to the input 13 and a single impulse is transmitted through the highway 18 reconstructed at the output 23, making the installation in 1 of the trigger 7, and after a time interval determined by the counter 2, at its transfer output, a signal is produced that sets the signal to the 1 trigger 6.

Compared with the prototype due to the use of a bipolar code with a return to zero, the proposed device is characterized by increased noise immunity.

Claims (1)

Invention Formula A device for connecting subscribers to a common highway, containing three counters, a first trigger, two elements AND and two elements OR, a device request input is connected to a setup input of 1 first trigger, a device request input input is connected to a reset input O of the first trigger and the first input of the first element OR, the output of the first element AND is connected to the second input of the first element OR The device bit is connected to the third input of the first element OR, the output. The first trigger is connected to the first input of the first element I, the counting inputs of the first and second counters are connected to the synchronization input of the device, the input of the initial installation of the device is connected to the installation input O of the third counter, characterized in that, in order to improve the transmission performance of information on the common highway, Three triggers are inserted into it, a trunk transceiver amplifier, the output of the first trigger connected to the reset input on the second trigger, the transfer output of the first counter connected to the second the stroke of the first element And the gate input of the second trigger, the output of which is the output of the device acquisition confirmation, the input of the device priority code is connected to the information input of the first counter, the input of the initial installation of the device is connected to the reset input O of the third trigger, the direct output of which is connected to the first the inputs of the second elements AND and OR, the outputs of the second elements AND and OR are connected to the input gate third ™ ten 1564639 8 its trigger and the reset input on the fourth trigger, respectively, the inverse output of the third counter is connected to the asynchronous loading input of the first counter, the output of the first element OR is connected to the clock input of the main transceiver amplifier, the input-output of which is the information input-output of the device, the information input of the main the transceiver amplifier is connected to the serial information input of the device, the information output of the device is connected to the information output of the master A transceiver amplifier, the clock output of which is connected to the second input of the second element I, the gate input of the fourth trigger, the installation input O of the second counter and the counting input of the third counter, the output of the fourth trigger second connected to the second and third overflow outputs The third counters are connected to. the installation input in 1 of the third trigger and the second input of the second element OR 30, respectively, 15 20 25