SU879588A2 - Multi-channel priority device - Google Patents

Description

I

This invention relates to the field of computing.

According to the main auth. No. 769543 of a well-known multichannel priority device used in managing the sequence of calls of several subscribers to a shared resource and contains an OR element, a trigger in each channel, four AND elements, two OR elements, an HE element, and a pulse generator. Each request input device is connected to the first inputs of the first and third elements And the input of the pulse generator of the corresponding channel. The first inputs of the second elements And channels are connected to the clock input of the device-. Output., The pulse generator channel is connected to the first input of the first element of the channel. The output of the first element OR channel is connected to the second input of the first element AND channel, the output of the first element AND channel - to the input

element of the channel and in one of the input of the fourth element of the channel. Other inputs of the fourth element of the AND channel are connected to the outputs of the elements of NOT preceding channels, the output of the fourth element of the AND channel is with the second input of the second element of the AND channel and with the corresponding input of the second elements OR preceding and after the blowing channels. The outputs of the second elements AND and OR of the channel are connected respectively to the installation and damping inputs of the channel trigger. the channel trigger input is connected to the second input of the third element I of the channel and to the corresponding permitting device. Left the third elements And the channels are connected to the corresponding inputs of the CM element, {inverse of which is connected

20 with the second inputs of the first elements of the OR channels.

J CTOBepHocTb of operation of this device is insufficient, as occurrence 3: the highest priority signal at the corresponding interrogation input leads to the formation of a voltage on the permissive output of this channel to connect the subscriber to the common resource. In this case, the beginning of the reception of information occurs at the moment of switching, when the transients have not yet ended, which leads to a distortion of the received information. . The aim of the invention is to increase the reliability of the device. The goal is achieved by the fact that an additional element OR and a pulse shaper are introduced into the proposed multichannel device. An additional element I is introduced into each channel. First and second inputs of an additional element AND each channel are connected respectively to the output of the fourth element AND of the same channel and zero output of the trigger the channel, and the output to the corresponding input of the additional element or the output of which is connected through the pulse shaper to the control output of the device. The drawing shows the functional scheme of the three channel device. It contains channels 1-4, each of which includes a generator of 5 pulses, the first element OR 6, the first element AND 7, the element NOT 8, the fourth element And 9, the second element OR 10, the second element And 11, trigger 12 and the third signal And 13 and the OR element 14. In the drawing, there are interrogation inputs 15-18, a clock input 19, and enabling outputs 20-23 of the device. The device also contains an additional element OR 24 and a pulse expander 25, and in each channel - additional elements AND 26. The device operates as follows. When a request is made on several inputs, the generators 5 of these channels form strobe pulses, the beginning of which coincides with the beginning of the signals in the corresponding channels, and the duration of the strobe pulses are fixed. Both the signal and the strobe pulse are clocked, i.e. their beginning and end coincide with the clock pulses, which are fed to the clock input 1 During the signal and the pulse gate at the output of the element 9, the voltage of the logic unit is only in the channel with the highest priority. This voltage sets the triggers 12 of all the other channels to the initial zero states, and when the clock pulse arrives, the trigger 12 of this channel is set to one, forming a control voltage at the permissive output of this channel. In addition, if there is a signal at the request input, the transition of the trigger 12 to the single state ensures the formation of a logic zero voltage at the second inputs of the OR6 elements of all the channels. At the end of the strobe pulse at the output of the generator 5 and the presence of a signal at the request input of this channel, the signal at the other input, eg, at the request input 16 of the second channel, passes through the AND 7 circuit of channel 2 if there is a pulse at the output of the generator 5 of this channel. & The first impulse of this element AND 13 of channel 2 sets the trigger 12 of this channel to the single state, and the triggers 12 of all other channels return to their original states. At the end of the signal at the request input 15 of channel 1 and the presence of the request signal, for example, at the request input 6 of channel 2 and the absence of a pulse at the output of the generator 5 of the second channel from the inverse output of the OR 14 element, the load on the second inputs of the OR 6 elements logical unit, thereby ensuring the passage of the signal through the element And 7 of this channel. Further recording on the trigger 12 of this channel is similar. When signals are received at several inputs, the most priority signal is gf at the first input of the element I 26 of its channel, at the second input of which there is a voltage of a logical unit from the zero output of trigger 12, which is still in the initial state. As a result, an impulse is generated at the output of the AND element 26, which, through the IL 24 element, triggers the expander of 25 pulses and delivers a blocking signal at the control output 27. The impulse at the output of the AND 26 element exists until the trigger 12 of this channel is clocked arriving at input 19, does not switch this trigger to a single state.

The pulse expander is started each time the enable outputs are switched. The duration of this pulse is chosen greater than the duration of the transients.

Thus, the device allows to eliminate the distortions of the received information when switching the resolution of the pixel outputs, which is especially important in the case when high reliability of the received information is required.

Claims (1)

1. USSR author's certificate 769543, cl. G 06 F 9/18, 1978 (prototype).