SU1509918A1 - Computer to user interface - Google Patents

Abstract

The invention relates to computing and can be used in distributed computing systems for decentralized arbitration of subscriber requests for connection to a common backbone. The purpose of the invention is to expand the scope of application of the device by implementing the priority mode of servicing requests. The device has channels, each of which contains two counters, three flip-flops, two one-shot, two AND elements, an OR element, an NOT element. The device operates in two modes: arbitration mode and watchdog timer mode. In the first mode, the device works when the highway is free, in the second mode it is busy. To implement the watchdog timer, a counter is used that sets the order of service for subscribers during arbitration. When new requests are received during arbitration, the arbitration procedure is resumed from the initial state each time, thus ensuring priority for servicing requests to seize the highway. The watchdog mode allows you to protect yourself from a false seizure of the main line and from the withdrawal of a computer from the inter-machine exchange support routines. 1 il.

Description

The invention relates to computing and can be used in distributed computing systems for decentralized arbitration of subscriber requests for connection to a common backbone.

The purpose of the invention is to expand the scope of application by implementing the priority mode of servicing requests.

The drawing shows a structural diagram of the device kinal. The device channel contains counters (frequency dividers) 1 and 2, triggers 3-5, single vibrators 6 and 7, triggered by

rear and leading fronts, elements AND 8 and 9, OR 10 and 11, output 12 of a line blocking symptom, synchro 13, common line 14-16, element NOT 17, request input 18, request clearing input 19, 20 data tracking, information input 21, output 22 confirming the capture of a trunk.

Counters 1 and 2 have an organization similar to the organization of meters of type K155IE8. In the counter K155IE8, at the output of the division, signals appear in accordance with the specified conversion factor from 1 to 64, at the transfer input

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Signals with a division factor, 64, occur, regardless of the division ratio specified for the division output. The counter has a zero reset input and an account stop input.

The device works as follows.

The device can operate in arbitration mode when the main line is free and in watchdog mode when the main line is occupied. The request for the capture of the highway is entered when a pulse is applied to the input 18, while the trigger 3 is entered 1. If the common highway is occupied, i.e. on line 16 1, then device operation in. the arbitration mode is blocked, since the potential from the output of the element OR 11 and the element NOT 17 blocks the passage of signals from the division output of counter 1 through element AND 9. The signal from the output of the element of RSHI 11 is also set to 1 trigger 5.

When the occupancy level is removed from line 16, the passage of signals through element 9 is unblocked. On the falling edge of the signal on the line driver, a pulse is generated, which is used to reset the counters 1 and 2 (which start counting in all channels, starting from the initial state, the counter 1 is allowed, as the trigger 5 remains in the 1. The device starts to operate in arbitration mode. The states of the counters 1 change at the same frequency from the inputs 13. The division ratio of the counters 1 of the different channels is set different (for example, for the first channel two, for the second one, for the third About four, etc.) therefore the pulses at the division outputs of the counters 1 of the different channels are produced at different points in time.

By the signal at the output of the counter 1, the trigger 5 of the corresponding channel is set to O, the counter enable signal I of the counter I is removed and it stops the counting. If during the formation of the signal at the output of the counter 1 in the trigger 3 of the corresponding channel O (there is no request to capture the trunk), then at the input of the installation in O of the trigger A there is an installation signal in O that blocks the effect of the output signal

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0 0 .with

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five

nor, coming through element 9 at the C input of trigger 4. If during the formation of a pulse at the division output of counter 1 in trigger 3 of the corresponding channel I (request to capture the trunk), then there is no installation signal at the input of the installation of trigger 4 and the signal from the output dividing counter 1 through element 9 to the C input of trigger 4 is recorded into it 1. The corresponding subscriber receives a confirmation signal that the line is captured from output 22, and line 16 uses the OR II element to output the level of the line (1) , while the input is reset and counters 1 and 2, an OR signal is supplied through the OR 10 element, which is generated at the leading edge of the pulse shaper.

When I on line 16, the triggers 5 are set to 1 state allowing the counting mode of the counters 1, while the NOT 17 blocking the passage of pulses from the division output of the counter 1 through the AND 9 element. If none of the subscribers made a seizure request line (in the triggers 3 O), then by the transfer signal at the counter 1 channel with the highest number, the counting mode of the counters 1 of all channels is blocked, since by the specified time point the triggers 5 of all channels are set to O. The arbitration mode is blocked until it is formed request n and the seizure of the highway by any subscriber. The request is triggered by trigger 3 with a signal applied to input 18, and the signal through the OR I1 element is output to line 16. By a signal on line 16, the triggers 5 of all channels are set to state 1, and counters 1 and 2 are reset. as a result, the arbitration procedure is resumed, starting from the initial state. If during the arbitration procedure, prior to the capture of any of the subscribers, a request is made to enter 18, then, when the corresponding signal is transmitted via line 16, counters 1 and triggers 5 are reset to their original state, resulting in the arbitration procedure starting from the initial state i.e. first check whether the requirement to seize mag. 515099

If the first subscriber sends a message, if not, then the second subscriber checks whether the second subscriber issues a request; if not, then the third subscriber checks the request and so on to determine the first order channel that has the request to acquire the trunk (1 in trigger 3). This is the organization of arbitration in

differences from the known from allows to handle requests for the capture of the magistrales in the order of their priority.

To release the common highway, the subscriber who captured it exposes a signal to input 19, while trigger 3 and, respectively, trigger 4 (the installation input of which is connected to the output of trigger 3) records O, and as a result the line 16 is removed from line 16 besides, output 22 is an acknowledgment signal for a line capture.

When a common highway is captured and a busy signal is placed on line 16, the device switches to watchdog timer mode. At the same time, on the leading edge of the busy signal on line 16, the one-shot 7 produces a signal that sets the O and the counters 1 and 2 through the element OR 10. When the busy signal (1) on line 16 is input to the installation of 1 trigger 5 The signal from the division output of counter 1 arriving at the C input of the trigger 5 (the installation input is more priority than the C input) is sent to the D input of the trigger 5 continuously O). For each data tracking signal on line 15, the OR 10 element is set to O counters 1 and 2. At the counting input of counter 1, it is constant. clock frequency is supplied, so the transfer signal of counter 2 (the clock input of which is connected to the transfer output of counter 1) is generated if, when the common highway is busy for the interval specified by counters 1 and 2, through line 15

no pulse appears, i.e. for the time specified by the watchdog timer, there is no data transfer.

The transfer signal of the counter 2 in the channel that captures the highway produces a signal at the output of the element 8, through which resetting the trigger 3 and, respectively, trigger 4 (since its input is connected with the output of trigger 3),

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5 Q .Q j.

five

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resulting in an automatic release of the common highway.

Claims (1)

Claims An apparatus for connecting a source of information to a common highway containing K channels (where K. is the number of subscribers), each of which contains the first and second counters, the first and second triggers, the first OR element, the NOT element, the first AND element, whose output connected to the synchronization of the first trigger, the output of which is connected to the installation input to the second trigger, characterized in that, in order to expand the scope of application by implementing the priority query service mode, each channel of the device It contains the second element AND, the second element OR, the third trigger, the first and second single vibrators, the outputs of which are connected respectively to the first and second inputs of the first OR element, the output of which is connected to the installation inputs of the first and second counters, the transfer output of the first counter is connected to the counting input of the second counter, the output of which is connected to the output of the blocking attribute of the device’s main line and to the first input of the first element I, the second input of which is connected to the output of the master's capture confirmation whether the channel of the device, the first input of the second OR element, and the output of the second trigger, the synchronous input of which is connected to the output of the second AND element, the first input of which is connected to the output of the NOT element, the output of the third trigger is connected to the counting enable input of the first counter, the output of which is connected to the second input of the second element I with the synchronous input of the third trigger, the information input of which is connected to the device logical zero bus, the synchronous input and the input of the device channel request clearing are connected respectively to the counting input the first counter and the input of the installation in O of the first trigger, the installation input in 1 of which is connected to the input of the device channel request and the second input of the second element OR, the output of the second elements OR of all channels of the device are connected according to the Mounting OR scheme. and connected to the inputs of the first and second od1509918 novibrators, the element input NOT and the installation input into 1 third of the trigger of each channel of the device, the maintenance inputs of all channels eight The devices are combined according to the INSTALLING OR scheme and are connected to the third inputs of the first OR elements of all the channels of the device.