SU1612302A1 - Multichannel priority device - Google Patents

Abstract

The invention relates to computing, in particular, to priority devices, and can be used to control the access of several subscribers to a shared resource. The aim of the invention is to increase the reliability of operation by reducing the likelihood of losing requests. The device contains three elements OR, a trigger, two elements OR-NOT, three elements NOT, two groups of elements AND, a pulse generator (GTI), two elements AND, a register, a counter, a decoder, and in each channel there is a trigger, an element AND OR. In the device, the request with the highest priority is served not by the last pulse from the GTI output, but by the first pulse. The device performs a constant analysis of the status of priority channels with simultaneous viewing of lower priority channels. For example, if a request is received in the Nth channel, which has the lowest priority, the device starts “watching” the channels, starting from the first. 1 il.

Description

The invention relates to computing, in particular, to priority devices, and can be used to control the access of several subscribers to a shared resource.

The purpose of the invention is to increase the reliability of operation by reducing the likelihood of loss of requests.

The drawing shows a block diagram of the device.

The device contains elements OR 1, triggers 2 and 3. elements AND 4, the first element OR-NOT 5, the second element OR-NOT 6, the generator 7 pulses (GTI). the first element is NOT 8, the first element is AND 9, the first element is OR 10, the first group of elements is AND 11, the counter 12, the third element is OR 13, the decoder is 14, the third element is NOT 15, the second element is OR 16, the second element is AND 17, the second element is NOT 18, the second group of elements And 19, the register 20, the output 21 of the device, the request inputs 22 of the device, inputs 23 End of the exchange, input 24 General reset the device, the input 25 of the installation in O and channels 26.

The device works as follows.

Before operation of the device, input Master 24 is given a master reset, which resets all the triggers of 2 channels 26 to the zero state. After time t, equal to the reset time of all channel triggers, a signal is applied to input 25. This signal leads to the initial (zero) state trigger (general reset) 3. After these preparatory signals, the device is ready for operation and requests are received to the request inputs 22 of the device from subscribers. Suppose there are requests from subscribers in the first and last channels, then the trigger ND SA

ABOUT

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The 2 channels of these channels are set to one. Single signals from the outputs of these triggers are fed to the corresponding inputs of the first element OR NOT 5, the output of which is a zero signal, which enables the operation of counter 12: (i.e., a single signal is removed from the input R; ) and which, having turned on the first element NOT 8, goes to the second input of element AND 9. At the third input of this element there is also a single signal from the output of the second element OR NOT 6. From the GTI output 7 pulses

i arrive at the second input of the element I 9 and from its output at the counter 12. So, the first pulse arrives at the counter 12. At the output of the counter, the unit code is generated. This binary code arrives at the second; The group of elements I 19 and the decoder 14.; On the first output of the decoder 14 pov -; A single signal is transmitted through the element OR 16 to the first input of the second element AND 17 and, moreover, to: the second input of the element AND 4 of the first channel. I Since there is a request in this channel, a single signal from the output of the AND element 4 of this

the channel is fed to the first input of the second element OR NOT 6, with the zero signal c; the output of this element element And 9 is closed; on the third entrance, and on the meter 12

impulses from GTI do not come. Zero sig; From the output of the second element, OR-HE 6 i enters through the element NOT 18 to the second input of the element AND 17, at the third input of which i there is a single signal from the output of the element i NOT 15. At the output of the element 17, a single signal appears enters I first inputs of elements AND 19 of the second group, which allows passage of the code from the output of counter 12 to register 20, this code arrives at output 21. After the end of the service of the first channel, device exits a signal 23 at the end of the exchange. On this signal, trigger 2 of this channel is reset to zero, the output of element 1/1 4 also sets a zero signal, which means that at the output of the second element OR NOT 6 there will be a single signal that will reset register 20 to O, passing through element NOT 18, goes to the second input of the element And 17, a zero signal from zyho.- yes which closes the second group of elements And 19, and the same single signal goes to the third input of the first element And 9, which will allow the passage of pulses from the GTI to the counter 12. When a second pulse arrives at counter 12 per er A binary code of two (i.e. a second channel) appears on output. This code goes to the second group of elements And 19 and to the decoder 14,

at the second output of which a single signal appears, which goes to the second input of the element AND 4, to the first input of the first element AND 11 of the first group (the first element AND in this group corresponds to the first channel, etc.) and passed through the element OR 16, to the first input of the element 17, on the third input of which a single signal from the output of the element is NOT 15 in the case of the absence of a request from the first channel, and on the second - a zero signal from the output of the element 18. That means that the output of the element 17 sets zero signal that will not allow code to pass through output from the counter ki

5 12 to register 20, This indicates that there is no request in the second channel. The first element of AND 9 remains open. At its second input, the next pulse arrives from the GTI, and so on. If, when viewing the second channel post0 PML, the request to the first channel is higher, then since the first input of the first element AND of the first group of elements And 11, corresponding to the first channel, is a single signal from the second output

5 decoder 14, and at the second input of this element And - a single signal from the output of the trigger 2 of the first channel 26, therefore, at the output of the first element And 11 of the first group sets a single signal,

0 which, having passed through the element OR 13 and through the first element OR 10, will reset the counter 12 to the zero state, the same single signal from the output of the element OR 13, after inverting on the element NOT 15,

5 goes to the third input of the second element And 17, the zero signal from the output of which will prohibit the binary code (in this case, two) from passing to the register 20. Thus, the next impulse of the city goes to counter 12 and its contents increase by one, t. e. becomes equal to one, and the device proceeds to service the first, highest priority channel.

After serving his device

5 continues to watch the following channels. If from the second channel to (N-1) -ro (N is the number of requests) there is no request channel, then the device serves the Nth channel having the request. Channel N has the lowest priority. From the output of counter 12, the N-ro channel code will go to register 20. If, after servicing the last channel, no more requests were received, a single signal from the output of the first element OR NOT 5

5 will reset the counter to O, if a request is received in any of the channels, then counter 12 is reset to O when the number N is reached by the next pulse. If, after servicing, for example, the {N-4) -ro channel no longer had any requests in channels with

If the number is greater than N-4 or in channels with a lower number (i.e., higher priority), then counter 12 is reset to O with a single signal from the output of the first element OR NOT 5.

Thus, at the beginning of work, when a request is received in channels, the device starts watching channels, starting with the first one, i.e. top priority. Reach the channel that has the request and is currently the highest priority (time, the device starts to service it. After servicing this channel, the device organizes viewing channels backward using the first group of elements 11). If it turns out that there are more priority channels there is a request, the device goes to the first channel and sequentially scans all the channels.

. If there is a request in one of the channels, the device proceeds to its maintenance. If there is no request behind and there is a request ahead, i.e. in lower priority channels, the device continues to browse the channels forward until it determines the channel with the request and starts its maintenance. The forward and backward channel scan is performed at each step, i.e. with each pulse arriving in the counter 12. If there are requests both behind and in front, then the counter 12 is forcedly reset to 0 with a single signal from the output of the first group of elements 1/111.

Formula a and 3 of the brend Multichannel device priority, containing the first element MLI-NOT, counter, decoder, pulse generator, the first element And the first element is NOT, and in each channel - the trigger and the element And, with the direct output of the channel trigger connected with the first input of the element AND channel and with the corresponding input of the first element OR NOT, the output of the pulse generator 4 is connected to the first input of the first element AND whose output is connected to the counting input of the sensor whose outputs are connected to the inputs of the decoder whose outputs are connected to the second inputs of the AND elements of the corresponding channels, the output of the first element OR NOT through the first element is NOT connected to the second input of the first element AND, characterized in that, in order to increase the reliability of the device by reducing the probability of loss of requests, it has a trigger, a second element OR NOT, a second; element AND, two elements NOT, three elements OR, the first and second groups of elements AND, a register, and in each channel an element OR, with the first inputs of the elements OR channels connected to the output trigger output element OR ka ala connected to the zero input of a flip-flop, flip-flops channel outputs are connected to first inputs of AND gates of the first group, an output of first OR-NO element is connected to the first input of the first OR gate, the third input of the first AND element is connected to the second output. element OR NOT, with the register reset input and through the second element NOT to the first input of the second element AND, the second input of which is connected to the output of the second OR element, the first output of the decoder is connected to the first input of the second OR element and to the second input of the first AND element of the first group , the i-th (I 2 ... N) output of the decoder is connected to the 1st input of the second element OR and to the second inputs from the first to the 0-1) -th element AND of the first group, the outputs of the elements AND of the first group are connected to the corresponding inputs the third element OR whose output is connected to the input of the third element is NOT and the second input of the first element OR, the output of which is connected to the reset input of the counter, the outputs of which are connected to the first inputs of elements AND of the second group, the second inputs which are connected to the output of the second element I, the third input connected to the output of the third element NOT The outputs of the elements AND channels are connected to the corresponding inputs of the second element OR NOT, the information inputs of the register are connected to the corresponding outputs of the elements AND the second group, the outputs of the register are the outputs of devices a, the request inputs and the end inputs of the device exchange are connected respectively to the direct inputs of the channel trigger and to the second inputs of the OR elements of the channels, the general reset and installation inputs in the device O are connected respectively to the direct and inverse trigger inputs.

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Claims (1)

Claims A multi-channel priority device comprising a first OR-NOT element, a counter, a decoder, a pulse generator, a first AND element and a first NOT element, and a trigger and an AND element in each channel, the direct output of the channel trigger connected to the first input of the channel AND element and the corresponding input of first OR-NO element, the pulse generator output is connected to the first input of the first aND gate whose output is connected to the counting input ^and from etchika which outputs are connected to inputs of the decoder, the outputs of which are connected s to the second inputs of the elements AND corresponding channels, the output of the first element OR NOT via the first element is NOT connected to the second input of the first element I. characterized in that, in order to increase the reliability of the device by reducing the likelihood of loss of requests, a trigger is introduced into it , the second OR-NOT element, the second AND element, the two NOT elements, the three OR elements, the first and second groups of AND elements, the register, and in each channel, the OR element, with the first inputs of the OR elements of the channels connected to the trigger output, the output of the element OR channel with dinene with a zero input of the channel trigger, the outputs of the channel triggers are connected to the first inputs of the AND elements of the first group, the output of the first OR-NOT element is connected to the first input of the first OR element, the third input of the first AND element is connected to the output of the second, OR-NOT element register reset and through the second element NOT with the first input of the second AND element, the second input of which is connected to the output of the second OR element, the first decoder output is connected to the first input of the second OR element and to the second input of the first AND element of the first group , the i-th (I = 2 ... N) output of the decoder is connected to the l-th input of the second OR element and to the second inputs from the first to (| -1) th elements of the first group, the outputs of the elements of the first group are connected to the corresponding inputs of the third OR element, the output of which is connected to the input of the third element NOT and the second input of the first OR element, the output of which is connected to the counter reset input, the outputs of which are connected to the first inputs of the elements AND of the second group, the second inputs, which are connected to the output of the second element AND whose third input is connected to the output t of the third element NOT, the outputs of the elements AND channels are connected to the corresponding inputs of the second element OR NOT, the information inputs of the register are connected to the corresponding outputs of the elements AND of the second group, the outputs of the register are the outputs of the device, the request inputs and inputs of the end of the exchange of the device are connected respectively to the direct inputs of the channel triggers and with the second inputs of the elements of the OR channels, the inputs of the general reset and set to 0 devices are connected respectively with direct and inverse inputs of the trigger.