RU2231111C2 - Multichannel priority device - Google Patents

Abstract

FIELD: computer engineering.

SUBSTANCE: proposed priority device that can be used to control access of more than one subscriber to shared resource has coder, switches, OR gate, AND gates, and flip-flop.

EFFECT: enhanced speed and reliability of device due to reduced hardware requirement.

1 cl, 1 dwg

Description

The invention relates to computer technology, in particular priority devices, and can be used to control the access of several subscribers to a shared resource, for example, random access memory.

A multi-channel priority device is known that contains two pulse distributors, an encoder, a register, 3 OR elements, and in each channel there is a trigger and 2 AND elements, the output of the first AND element being connected to the trigger installation input, the trigger output to the channel AND element input, the output which is connected to the extinguishing trigger input [1].

The disadvantage of this device is a large amount of equipment and low speed.

The closest to the proposed technical essence and the achieved result is a multi-channel priority device containing N channels, each of which includes a trigger, two AND elements, an OR element, an inverter, a pulse distributor consisting of a GTI, an I element, a counter and a decoder [2 ].

The disadvantage of this device is the large amount of equipment.

The purpose of the invention is to increase the speed of the device and reliability by reducing the amount of equipment.

This goal is achieved by the fact that in the multi-channel priority device containing channels, an encoder instead of a pulse distributor consisting of a counter, a decoder, a clock generator, AND elements, keys are entered, the number of which corresponds to the number of channels, an OR element, and an AND element in each channel a trigger, and the output of the trigger of each channel is connected to the first input of the And element of its channel, the output of which is connected to the zero input of the trigger of its channel, with the OR element and with the corresponding information input the first key, the allowing input of which is connected to the output of the OR element, the first output - with the inhibitory input of the next key, with the first input of the encoder and the second input of the element And of the first channel, and the remaining outputs - with the information inputs of the next key, the first output of which is connected with the inhibit the next key input, the second input of the encoder and the second input of the AND element of the second channel, the rest with the information inputs of the next key, etc., the first output of the penultimate key is connected to the inhibitory input of the last key cha, with the penultimate input of the encoder and with the second input of the AND element of the penultimate channel, the second output is with the information input of the last key, the output of which is connected to the last input of the encoder and with the second input of the AND element of the last channel.

The device diagram is shown in the drawing.

The multi-channel priority device contains channels 1, each of which has a trigger 5 and an AND element 6, an OR element 3, an encoder 2, keys 4. The device contains inputs 7 and output 8.

The device operates as follows.

In the initial state, when there are no requests for servicing applications at inputs 7, trigger 5 of channel 1 is in the zero state. The inputs of the OR 3 element will have zero signals coming from the outputs of the triggers of 5 channels 1. As a result, the zero signal from the output of the OR 3 elements goes to the enable input of the first key 4, and from the outputs of the triggers 5 channels 1 they go to the information inputs of the first key 4. Accordingly the zero signal will be at the inputs of the encoder 2, and at the second inputs of the elements And 6 channels 1, and at the inhibitory input of each next key 4. Therefore, at the output 8 of the encoder 2, a zero code will be generated (no requests).

When at least one request is received in any of the channels 1, a single signal will appear at the output of the OR 3 element, which will open the first key 4, as a result of which a single signal will appear at the corresponding information input of the first key 4, which will block the passage of signals from triggers of 5 channels 1, the priority of which is lower, and will go to the input of encoder 2, at the output of which a binary code of the channel 1 number to which the request is received will be generated. The channel with the highest priority is currently selected.

Let's say the requests came in on the second and last channels. Triggers 5 of these channels will go into a single state. Single signals from their outputs will go to the corresponding inputs of the OR 3 element, the output of which will open the first key 4, and to the corresponding information inputs of the first key 4.

Since the first output of the first key 4 will have a zero signal, the single signals from the second and last outputs of the first key 4 will appear at the outputs of the second key 4. A single signal from the first output of the second key 4 will block the passage of signals through the next key, will go to the corresponding input of the encoder 2 at the output 8 of which a binary code of the channel number containing the request for servicing the application will be generated, and at the second input of the And element 6 of the second channel 1, at the first input of which there is a single signal from the output of trigger 5, this channel. Formed at the output of the And 6 element, a single signal will set the trigger to zero.

The zero signal from the output of trigger 5 will open the following keys 4, thereby ensuring the passage of a single signal from the output of trigger 5 of the last channel 1, which will reset trigger 5 of the last channel 1, and will be fed to the input of encoder 2, at the output of which 8 the code number of the last channel will be generated, containing a request for service applications.

The application of the invention allows to significantly reduce the amount of equipment of the device by replacing the pulse distributor, consisting of a counter, a clock generator, a decoder, and removing elements NOT and NOT, as well as increase performance due to the lack of a GTI and a counter. Moreover, if the counter has an account module N, then the maximum gain in speed when serving the last N-th request will be N times. On average, taking into account other requests ranging from the 1st to the Nth, the gain in device performance can be approximately determined as N / 2, where N is the number of served requests.

Sources of information

1. USSR copyright certificate No. 468240, cl. G 06 F 9/46, 1976.

2. Copyright certificate of the USSR No. 855664, cl. G 06 F 9/46, 1979 (prototype).

Claims (1)

A multi-channel priority device containing channels, an encoder, an OR element, each channel containing an AND element and a trigger, the output of which is connected to the first input of the AND element, the output of which is connected to the zero input of the trigger, the output of which receives single signals to the corresponding input of the OR element characterized in that a group of keys is introduced into the device, the number of which corresponds to the number of channels, while the information inputs of the first key are connected to the outputs of the triggers of the corresponding channels, allowing the first key is connected to the output of the OR element, the first output is with the inhibitory input of the next key, with the first input of the encoder and with the second input of the element And of the first channel, and the remaining outputs are with the information inputs of the next key, the first output of which is connected to the inhibitory input of the next key, the second input of the encoder and with the second input of the AND element of the second channel, the rest with the information inputs of the next key, etc., the first output of the penultimate key is connected to the inhibitory input of the last key, with the penultimate input of fractor and with the second input of the AND element of the penultimate channel, the second output is with the information input of the last key, the output of which is connected to the last input of the encoder and with the second input of the And element of the last channel, while the code of the channel number containing the service request is generated at the encoder output .