SU840868A2 - Interface - Google Patents

Description

one

The invention relates to computing and can be used to interface a digital computer with. external devices in computing systems with an extensive network of sources and consumers of information.

According to the main author. St. No. 736086 known an interface device comprising subscriber subchannels, a priority block, a synchronization block, a program readiness register, an information switch, a modular control unit, an exchange register, the first inputs and outputs of which are respectively the first information input and output of the device, the exchange control block , the first inputs and outputs of which are respectively the first control input and the output of the device, and the second input and output are connected respectively to the first output and input of the synchronization unit, the second second and third outputs of which are respectively connected to first inputs of subchannels subscribers and priority control input unit inputs and requests authorization to emasculate which are connected respectively

with the first outputs and BTOPIOMH inputs of the respective subchannels of subscribers, the third inputs of which are connected to the control outputs of the program readiness register connected by the information inputs and outputs of the exchange register and the input of the exchange register, respectively, and the fourth input

output of the synchronization unit, the fifth output of which is connected to the third input of the control unit modulo, connected by the first input and output, respectively, to the third

the output and input of the exchange register, and the second input to the third output of the control unit, the fourth output of which is connected to the fifth input of the exchange register, the fourth output and

the input of which is respectively connected to the information input and output of the information switch, the control input of which is connected to the sixth output of the synchroniaacin unit, and the outputs and inputs of the group of information inputs and outputs and the inputs of the group of address inputs are respectively connected to the fourth inputs, second and third outputs of the corresponding subchannels the information inputs, outputs and control inputs and outputs of which are, respectively, the second information, inputs and outputs, and the second control passages and exits the device as well. each of the subscriber subchannels contains a control node, an overhead register connected to the first input and output, respectively, with the first output and input of the control node, and the second output and input are respectively controlling the output and input of the subscriber subchannel, transfer type switch, first input and output which are connected respectively to the first output and input of the exchange subchannel register, and the second input and output are respectively the information input and output of the subchannel, the second input and output of the exchange register on the subchannel are the fourth input and the second output of the subchannel, respectively, the AND element, the first input of which is the third input of the subchannel, and the output is connected to the second input of the control node, the third and fourth outputs of which are connected respectively to c. the third inputs of the transfer type switch and subchannel swap register, and the fifth output to the third output of the subchannel, a ready trigger, connected by the input and output respectively to the sixth control output and to the first output of the subchannel, respectively, and the OR element, whose inputs are respectively the first and the second inputs of the subchannel, and the output is connected to the second input of the element I 1}.

A disadvantage of the known device lies in the low reliability of the exchange, since with an increase in the total flow of information through the device, undetectable losses of individual words from information sources (external devices) are possible.

In multiplex exchange mode with sources and consumers. Formations can be distinguished three stages of the operation of the channel of an obmen when receiving:

- reception of the word In the subscriber's subchannel from the subscriber;

- waiting for a subchannel connection to a subscriber with an exchange processor;

 transfer of the word from the subscriber subchannel to the exchange processor.

The receipt of the next word from the subscriber before the end of all three stages means its loss, since each of the subscriber subchannels has only one exchange register, a buffer in which one information word is memorized before being transmitted to the exchange processor. If the previous word has not yet been transferred from the sub-channel exchange register to the exchange processor, a new word from the subscriber is not accepted.

subchannel to the exchange register, still occupied by the previous word, and the new word will be lost.

The purpose of the invention is to increase the reliability of the exchange by detecting the loss of a word during the exchange.

5 The goal is achieved by haem, that in a known device, the fifth inputs of the subscribers' sub-channels are connected to the seventh output of the block of the synchronization, the fourth outputs - to

0 to the sixth input of the exchange register, and fifth outputs to the second input of the synchronization unit, the subscriber's subchannel additionally contains an occupation trigger, a word loss trigger,

5 I-sign element of the word and the element AND of the sign of word loss, the busy trigger inputs are connected respectively to the third input of the subchannel exchange register and the first input of the service signal register, the second input of which and the output of the busy trigger are connected to the corresponding inputs of the word sign element output connected to the fifth output

subchannel and trigger loss input

words, output connected to the first input element AND sign of word loss, the second input and output of which are respectively the fifth input and the fourth output of the subchannel.

The drawing shows the block diagram of the proposed device.

The device contains the exchange register 1, the exchange control block 2, the synchronization block 3, the priority block 4, the subscriber subchannels 5, the modulo control unit b, the information switch 7, the program readiness register 8. Each subscriber subchannel 5 consists of a register 9 exchange

subchannel, control node 10, overhead register 11, transfer switch 12, readiness trigger 13, AND 14 and OR 5 15 elements, busy trigger 16, AND word sign element 17, word loss element 18, and word loss element 19 .

In addition, the device contains a P processor 20 exchange and subscribers 21.

The device works as follows.

Each word transmitted from subscribers 21 is accompanied by a service signal of the Start type and sequential codes type.

wa

Removal allowed for parallel codes, etc.

Such a service signal is received from subscriber 21 to register 11 before 0 by the first information bit of the word of the sequential code, or it accompanies the information bits of the word of the parallel code.

With the correct operation of the source of information (subscriber), the transfer of a new word from a non-HO cannot take place until the end of the transfer of the previous word. The word loss loss detection circuit begins to track the arrival of a new word from the moment the reception from the subscriber of the next word to register 9 and the transition of subchannel 5 to standby mode with register 1 is completed to transfer the word to exchange processor 20.

The moment of the end of the reception of the previous word from the subscriber 21 and the transition of the subchannel 5 to the standby mode of communication with the register 1 is fixed by the signal of the control unit 10, which sets the trigger 16 for the busy state to one.

Termination of word loss tracking is performed after completion of the transfer of the next word from the subchannel to the exchange register 1. In this case, the trigger 16 is set to the zero state by a signal from the control node 10 to the zero input of the trigger 16.

This moment is the end of the work station subchannel occupancy with the previous word and the beginning of readiness to receive the next, new word.

The coincidence of the busy sign from the single output of the trigger 16 and the signal of the Beginning of the word (or Removing is allowed) from the corresponding control input of the subscriber's subchannel at the inputs of the And 17 element detects the loss of the word.

The word loss signal from the output of the element 17 sets in one state the word loss trigger 18 and, through the fifth output of the subscriber's subchannel, enters the synchronization unit 3 as a signal that a word has been lost from one of the subscribers 21..

(Sync block 3 transmits

this signal is via exchange control unit 2 to exchange processor 20.

The exchange processor issues an exchange command with regis 1 for requesting information about the subscriber subchannel numbers in which the word loss occurred from the respective subscribers 21.

The command is decrypted by block 2, which starts block 3 and prepares it for autonomous work on issuing this information to the exchange processor.

In the process of executing this command, block 3 queries the state

flip-flops 18 by a signal applied to the inputs of the And 19 elements, from the outputs of which the word loss signals go to register 1 bits corresponding to the subchannel numbers 5.

Then, according to the signal from the synchronization unit 3, the unit 2 outputs to the exchange processor 20 information about the loss of the word on the subscriber’s subchannel number (s) from the exchange register 1.

0

Thus, the device allows the exchange processor to receive information about the loss of the word from the respective subscribers 21 and to re-exchange with them to obtain

5 full information, given multiplex exchange with a reduced number of subscribers, which provides increased reliability of the exchange.

20

Claims (1)

1. USSR author's certificate 5 736086, class G 06 F 3/04, 1978 (prototype).