SU1683023A1 - Common bus multiport access controller - Google Patents

Abstract

The invention relates to calculating techniques and can be used to organize the exchange of information in remote networks, multi-machine and multiprocessor distributed systems. The purpose of the invention is to increase speed. The device contains three elements AND, element NAND, delay element, three triggers, notch filter, threshold element, element NOT. In the device, the speed is improved by eliminating the need to wait for the counter overflow signal on the device with the highest priority. 1 il.

Description

The invention relates to computing and can be used in organizing the exchange of information through a common backbone between subscribers of local area networks, multi-machine and multiprocessor distributed systems.

The purpose of the invention is to increase the speed of the device.

The drawing shows a block diagram of the device.

The device contains output 1 of the device for connection to the trunk, element 2, isolation, one-shot 3, register 4, counter 5, triggers 6-8, element AND-OR 9, element 10 delay, elements OR 11-13, elements AND 14-16 , I-NE element 17, notch filter 18, threshold element 19, NOT element 20, switches 21 and 22, line 23, input 24 of the initial installation of the device, input 25 of the end of the device message, input 26 of the device request, input 27 of the end of the device request, device failure output 28, device resolution output 29, device signal input 30, information th device input 31, device clock input 32, device input 33 for connecting to the trunk

The device works as follows.

The device controls the access of the user equipment (computer, processor) to the common trunk. The device constantly listens on the trunk and can start transmitting working information from the subscriber to the trunk if there is no transmission of signals from other devices in it. Since the devices are separated from each other for a certain distance, they can determine whether the line is occupied with a delay equal to the total signal propagation in major and the response of the device elements. This leads to the fact that any device can start the transfer of information)

to the trunk, while the other device is already transmitting. In this case, there is a collision of information in the highway. Devices whose information transmissions collided in a trunk determine the fact of a collision by comparing the signals emitted by the device and the signals in the trunk. If the signals are different, this indicates a collision in the highway.

Conflict between devices over the use of the trunk is resolved by issuing priority sequences of signals. After collision detection, the conflicting devices stop issuing information and start issuing sinusoidal signals to the trunk with a frequency characteristic of only this device and simultaneously using the priority counter determine the duration of the priority sequence pulses, which is determined by the contents of the address register. The higher the priority of the device, the longer the sequence of pulses. The remaining devices, without receiving the signal End of the message, do not attempt to transfer information to the trunk. Signal The end of a message is separated by user equipment from information transmitted via the trunk.

The winner in the fight for access to the highway is a device that determines that only sinusoidal signals remain in the highway with its frequency. This means that the priority of the proposed device turned out to be the highest and, having stopped counting the intrinsic duration of the priority sequence of pulses, begins to transmit working information. At the end of the transfer, any device can start the transfer of working information.

The initial state of the device is determined by a pulse, which comes from the input 24 of the device. The pulse through the element OR 11 sets the trigger 8 to one state, through the element OR 13 resets the trigger 6, and through the element OR 12 resets the trigger 7. The presence O on the direct output of the trigger 6 means that the input of the switch 21 is connected to the first output, and its output is connected to the output of the switch 22. If signals are not transmitted through the trunk to any devices, then trigger 8 remains in one state and the signal from input 26 of the device through the ILI element AND 9 sets trigger one to one. High potential from single output

trigger 7 is fed to the output 29 of the device, allowing the subscriber equipment to issue working information, as well as to the element 16, allowing the information to pass from the input 31 of the device through the element 16, the switch 22 and element 2 to the trunk 23.

Subscriber equipment on the specified chain produces the issuance of working information.

To determine the collision of information transmissions, elements AND 14 and 15, AND-NE 17 and delay element 10 are used. The potential that permits the issuance of working information to the trunk from the direct output of trigger 7 also goes to the input of the AND 14 element and to the input of the AND-NOT 17 element. Information pulses from the output of the AND 16 element, besides the highway,

0 also arrive at the input of the element 10 delay. All signals from the trunk through switch 21 arrive at the input of element AND 14. Elements AND 14 and 15 and element IS-NOT 17 realize the negation function equal to 5 values for the signals entering the input of element 14 and the second input of element J / I-HE 17 In the absence of collisions in the highway, the signal at the output of the element And 15 is missing. If there is no collision in the magisgram, the information is fully output, after which the trigger 7 is reset by the signal from the input 27 of the device.

In the presence of transmission from the highway, the pulses through the switch 21 arrive at

5 input of one-shot 3, from the output of which the signal resets trigger 8, the direct output of which prohibits maintenance of a new request for transferring information from these devices to the trunk. If at this time a signal is received by the Request from the input 26 of the device to transmit information, then its passage is hovered by the H- OR 9 element until the signal from the input 25 of the device arrives. By this signal, a trigger is set to one state which allows the trigger 7 to be set to one state, thereby allowing the release of working information. If there was a collision of transmissions in the master, then in each device, from the number of And 15 elements that participated in the transmission, signals appear that set trigger one to 6 and reset through element OR 12

5 trigger 7. The low potential from the trigger output 7 prohibits the release of information to the trunk. High potential from the trigger output 6 enters the device output 28 as a Failure signal, to the inputs of the priority counter 5 to enter the contents of the register 4 into the counter 5 and allows clock pulses to enter counter 5. In addition, a high potential from the output of the trigger 6 goes to the control inputs of the switches 21 and 22, and connects the input of the switch 21 to the second output, and to the output of the switch 22 a second input, thereby allowing the output from the device 30 Twa through the switch 22 and the element 2 in the line of sinusoidal signals with a frequency pri- sheer only the device. At the same time, the sinusoidal signals from the highway through the switch 21 are fed to the input of the filter 18, which is configured to suppress sinusoidal signals with a frequency inherent only in this device, i.e. their sinusoidal signals. Sinusoidal signals from other devices through the threshold element 19 are fed to the input element HE 20 and maintained on his O.

If the priority of the device is lower than that of the other device taking part in the match, i.e. the pulse sequence priority duration is shorter, then an overflow signal at the output of counter 5 appears earlier. This signal, through the OR element 13, resets the trigger 6, which, through the control inputs of the switches 21 and 22, transfers their B to the initial state, i.e. The output of the sinusoidal signals to the line is terminated, and the device enters the mode of waiting for the signal. End of the message, because the signal request from the input 26 of the device cannot pass through the AND-OR 9 element to the trigger installation input 7, since the input of the AND-OR element 9 receives a zero signal from the output of trigger 8, which was reset before the start of the stop.

If the priority of the proposed device is the highest, then at a certain moment only sinusoidal signals emitted by the device itself remain in the trunk. As soon as this happens, the output of the notch filter 18 and, accordingly, the threshold element 19, which is necessary to eliminate interference from the sinusoidal signal, appears. This, in turn, causes the appearance of 1 at the output of the element HE 20, which through the OR element 13 resets the trigger 6 and simultaneously enters the inputs of the AND-OR element 9, thereby setting the trigger 7 to one state. Since O at the direct output of trigger 6 brings switches 21 and 22 to their initial state, high potential from direct output of trigger 7 allows conflict-free output of working information to the trunk, which ensures the zero status of trigger 8 for all other devices. After this device has transferred all the working information in all devices, the trigger 8 is set to one and any device, if necessary, can start transmitting the working information via the trunk.

Claims (1)

Multi-channel access control device to a common highway containing channels, and in each channel an isolation element, a one-shot, a register, a counter, the first, second and third triggers, an AND-OR element, a delay element, the first, second and third elements OR, the first and second elements are AND, the NAND element, the device clock input is connected to the counter input of the counter, the register information outputs are connected to the information inputs of the counter, the overflow output of which is connected to the first input of the first OR element, my output of the first trigger is connected to the meter control mode input and is the device failure output, the device initial setup input is connected to the first input of the second OR element, to the first input of the third OR element, and the second input of the first OR element, whose output is connected to the reset input of the first trigger , the input of the device request end is connected to the second input of the third OR element, the output of which is connected to the reset input of the second trigger, the direct output of which is connected to the first input of the first element I. from the first The input input of the element is NOT and is the device enable output, the device request input is connected to the first input of the AND-OR element, the output of which is connected to the installation input of the second trigger, the input of the end of the device message is connected to the second input; connected to the installation input of the third trigger; the direct output of which is connected to the third input of the AND-OR element; the output of the one-shot is connected to the reset input of the third trigger; the output of the second element AND is connected to the installation input of the first trigger and the second the input of the third element OR, the output of the delay element is connected to the second input of the NAND element, the output of which is connected to the first input of the second element AND, distinguished by the fact that, for speed improvement purposes, the first and second switches are introduced into each channel of the device, And, the notch filter, the threshold element, the element is NOT, the first output of the first switch is connected to the input of the one-shot and the first input of the third element And the second output of the first switch is connected to the input of the notch filter, the output of which is connected to the input of a threshold switch, whose output is connected to the input of NOT circuit whose output is connected to a third input of the first elementayShSh and third and fourth inputs elvMMaShILI, direct output of the first flip-flop is connected with the control inputs of the first. 1 | | second switch, the information input device is connected to the second input of the first element And, the output of which is connected to the first 0 the information input of the second switch and the input of the delay element; the signal input of the device is connected to the second information input of the second switch, the output of which is connected to the input of the isolation element whose output is the output of the device for connecting to the highway; the direct output of the second trigger is connected to the second input the third element And, the outputs of the isolating elements of all the channels of the device are connected through mounting OR and connected to the information inputs of the first switches of all channels. thirty 31 o 27o