SU1686445A1 - Multichannel priority device - Google Patents

Abstract

The invention relates to computing and can be used in systems that control access to a common / resource. The aim of the invention is to reduce the number of lines of the common highway. The device contains K channels (K is the number of subscribers), with each channel containing two counters, three flip-flops, four AND elements, a main transceiver, and an OR element. The essence of the invention is that the capture is carried out by setting on the highway a pulse of duration K cycles, where K is the priority of the channel. Then the information is transmitted along the same line. The release of the trunk is carried out by setting a pulse with a duration greater than at least one clock period than the duration of the highest channel priority and the length of the transmitted information words. 1 il Yo

Description

The invention relates to computing and can be used in systems that control access to a common resource.

The purpose of the invention is to reduce the number of lines of a common highway.

The drawing shows a functional diagram of one of the channels of the device

The multichannel priority device contains K channels (K is the number of subscribers), each channel contains a counter 1 and 2, triggers 3-5, elements AND 6-9, a trunk transceiver 10, element OR 11, a common trunk (OM) 12, input 13 channel priority code, request 14 inputs, request 15 cancel, clock 16, request confirmation output 17.

The delay time of the trunk transceiver 10 must be less than the delay of the first counter 1. To fulfill the condition - the highest priority is given to the removal of a common resource, the duration of which is longer than the highest priority of the channel and information word for at least one clock period, to the inputs of the parallel information of counter 2 The appropriate code must be submitted.

The device works as follows.

A channel wishing to capture a shared resource, at the input of the AND 8 element from the input 14 of the channel, receives a high signal level. From the direct output of trigger 4 to the input element And 8 comes a high level. As a result, on the leading edge of the pulse transmitted from

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output element AND 8 through the element OR 11, the output of the trigger 3 appears a high level signal, which falls on the element ID 7 and through the main transceiver 10 at OM 12, with which through the main transceiver 10 low to high level sets to the first output of the trigger 4 is low, thereby prohibiting the signaling of a demand signal for a channel by any channel.

The high potential from the trunk transceiver 10 is transferred to the counting mode by the counter 2 and a high level is set at the output of the And 7 element, which transfers the counter 1 to the counting mode. In accordance with the priority taken at the code input 13 of the channel, a corresponding low number of pulses appears at the output of counter 1, which, having passed through the AND 6 element, resets the output of the trigger 3 signal, a low level that through the AND 7 element translates the counter 1 is in parallel recording mode, and via the trunk transceiver 10 translates the counter 2 in parallel recording mode and is set at the information input of the trigger 5.

After the delay time of the transition to the parallel recording mode, the output of the counter 1 is set to a high level, the transition to which fixes at the output of the trigger 5 a state on its information input. If the shared resource lock signal on OM 12 is set to one channel or the priority of this channel is the highest of all simultaneously set shared resource hooks, then OM 12 has a low level that fixes trigger 5. In this case, the output signal on its output informs the device about the capture share from the output of channel 17, and also sets the inhibit level at the input of the element And 7.

After finishing the data transfer via OM 12, the channel that captures the common resource, having received a positive level impulse at the input of the 15th channel, exposes OM 3 from the output of the Tri 3 Ger high signal level, similarly to the indicated procedure. At OM 12, a high level appears at which counter 2 is switched to counting mode. The remaining circuit elements do not change their state. At one of the inputs of the element And 7 is a low level from the output of the third trigger 5, therefore, the counter 1 remains in the parallel recording mode. Having counted up to the priority value of the capture of the trunk, a transfer signal appears on the second counter, through which

b the high level at the output of the trigger 3 is reset and the triggers 4 and 5 are reset to the initial state. At the output 17 of the channel, the capture signal OM 12 is taken, and

trigger levels 4 give an enable signal to the input element And 8 and a prohibiting signal to the input element And 9. The channels are ready for the next capture of OM 12.

If at one time exhibited requirements

0 by capturing OM 12 two or more channels, the highway will capture that channel whose priority is higher. The higher the priority, the greater the number written to the inputs of counter 1, and the later the transfer signal appears on its exit. In the lower priority channel, the transfer signal from the output of counter 1 at trigger 5 on the trigger 5 fixes a high signal level at the same time as the output of trigger 3

0 channel with higher priority high level not removed.

Claims (1)

Claims of the Invention A multichannel priority device containing K (K number of subscribers) KA5 Naloo, each of which contains two counters, three flip-flops, an AND element and an OR element, and the input of the priority code of each channel of the device is connected to the information input of the first counter, clock 0, the channel input of the device is connected to the write inputs of the first and second counters, the overflow outputs of the first and second counters are connected respectively to the synchronous input of the first and to the installation input of 1 second 5 triggers, the output of the first trigger is connected to the output of the device channel request confirmation, characterized in that, in order to reduce the number of common lines, each channel additionally 0 contains second to fourth And elements and a main transceiver, with in each channel the inputs of requesting and clearing the request for a channel of a device are connected respectively to the first inputs of the first and 5 second elements And whose outputs are connected respectively to the first and second inputs of the OR element, the output of which is connected to the synchronous input of the third trigger, the output of which is connected to the input of the main transceiver and the first input of the third element I. The second input and output of which are connected respectively to the output the first trigger and with the input of setting the mode of the first counter, the outputs of replenishing the first and second counters are connected respectively to the first and second inputs of the fourth And element, the output of which n with the input of the setup in the third trigger, the output of the main transceiver is connected to the third the input of the third element I, with the input of the set in O of the second trigger, with the information input of the first trigger and with the input of setting the mode of the second counter, the overflow output of which is connected to the input of the installation into 1 of the first trigger, direct and the inverse outputs of the second trigger are connected to the second inputs of the first and second elements AND, respectively, and the inputs to the outputs of the main transceivers of all the channels of the device are connected through mounting OR. /four 15 with PM