SU596948A1 - Multichannel priority arrangement - Google Patents

Description

(54) PRIORITY MULTI-CHANNEL DEVICE

tation. In addition, the presence of a clock pulse generator as part of the device limits its speed. A disadvantage of the known device is also that with an increase in the number of switching blocks, the number of connections between the switching blocks increases.

Moreover, a survey of information sources in known devices is carried out either according to predetermined priorities, or sequentially.

The prototype of the invention is a multichannel device of priority 4, which contains an AND element, and in each channel the first and second triggers and the OR element, with the channel's request input connected to the zero input of the first channel trigger, and the first input of the AND element connected to the control input of the device.

The disadvantage of this device is low-speed, since the overwriting of the service request signals from the register of indication of requests to the auxiliary register is performed on the clock signals only after the channel with the highest priority is served. And the polling signal always arrives with a delay for the duration of the process of rewriting and eliminating conflicts.

Another disadvantage of this device is the absence of a sequential polling of information sources and an on-line transition from a priority poll mode to a sequential poll mode, and vice versa. For the normal operation of this device, initial setup signals, clock signals, a polling signal are required, the organization of which requires additional hardware costs.

A common disadvantage of these known devices is that they cannot provide a quick transition from a priority survey to a sequential survey of information sources, and vice versa.

The purpose of the invention is to reduce the equipment and increase the flexibility of the device.

This is achieved by the fact that the device contains an OR element, and in each channel the element is NOT, the interrogation input of the i-ro channel (1 2, 3, ... n) is connected to the interrogative output () -ro of the channel, the interrogative output of the nth channel is connected to the inverse input of the OR element, the output of which is connected to the interrogative input of the first channel, the signal input i-ro (, 2, ... n- 1) of the channel is connected to the signal output (i + l) -ro of the channel, the signal input n th channel and the signal output of the first channel are connected respectively to the signal input of the device with the second input of the element I, the output of which is connected en with the direct input of the OR element, the channel interrogation input is connected to the single input of the first and the zero input of the second channel trigger, the single and zero outputs of the first canout trigger are connected respectively to the interrogation channel output and the single input of the second trigger channel, the single output of the second trigger the channel is connected through the channel NOT to the Razrelami channel channel and to the first input of the channel OR element, the second input and output of which are connected respectively to the signal input and the channel output.

The drawing shows the block diagram of the device.

The device contains: the first channel 1, the i-th channel 2, the n-th channel 3, the element OR 4, the element AND 5, the request inputs 6, the control input 7, the signal input 8, allowing the outputs 9, and in each channel the triggers 10 , 11, element 12, element OR 13. inputs 14, 15, outputs 16, 17.

The device works as follows.

There are two modes of operation. In the absence of a logical "1 at input 7, the serial polling mode. In this mode, after removing the request for exchanging the spent information source, the polling signal propagates to the next channel serving the information source with a lower priority.

In the presence of a logical "1 at input 7 - priority mode. In this mode, after the request to exchange the spent information source is removed, the survey begins with the channel that serves the information source with the highest priority.

In the sequential polling mode when there are no exchanging interrogation signals at the inputs 6 for the zero outputs of the triggers 10, there is a potential that goes to the single input of the triggers 11. The potential from the single output of the trigger 11 goes to the input of the HE elements 12. From the output of the HE element 12 to the output 9 Zero signals are coming. In the ring formed by the trigger 10 and the element OR 4, the generation of polling pulses occurs, since an odd number of inverters are closed in the ring (an even number - in the triggers 10 and the inversion at the input of the element OR 4).

The ring works in two cycles. The first cycle (the cycle of installation of the device in the initial state) is characterized by the fact that a single signal propagates from channel 1 and ending with channel 3. A single signal from the output of the element OR 4 through the interrogation input 14 is fed to the zero input of the trigger 11 and to the single input of the trigger 10. The trigger 11 is set to the single state, and a single signal appears through the single output of the trigger 10 through the interrogation output 16 to the polling input 14 of the next channel and spreads to the whole circuit in the same way. The second cycle (channel polling cycle) is characterized by the fact that a zero signal propagates in the circuit, starting from channel 1. But the propagation of a zero signal in a circuit is possible only if there are no interchange signals on the inputs. When one of the channels of the exchange request signal is present at input 6, a zero signal appears at the zero output of flip-flop 10. In the second cycle, this signal prevents the zero signal from propagating in the circuit. From this point in time, the generation of pulses in the ring is stopped. The zero signal from the zero output of the trigger 10 is fed to the single input of the trigger 11. As soon as the zero signal to the zero input of the trigger 11 arrives, the trigger 11 is set to the zero state.

The zero signal from the single output of the trigger 11 is fed to the input of the element NOT 12. From the output of the element NOT 12, a single signal goes to the output 9. As soon as the exchange request is removed from the input 6, the trigger 10 is set to the zero state. The single signal from the zero output of the trigger 10 is fed to the single input of the trigger I. The single signal from the single output of the trigger 11 is fed to the input of the HE element 12, as a result of which the signal at the output 9 disappears. A zero signal from a single output of trigger 10 propagates through the circuit to a channel, at input 6 of which there is a request for an exchange. Thus, all exchange requests are processed sequentially. After polling channel 3, the setup cycle follows, and then the survey cycle again.

In the priority mode from input 7 to the input of the element I 5, a logical unit arrives. In this case, a single signal from the output of the element NOT 12, which arrives at the output 9 and to the first input of the element OR 13, goes through the signal output 17, the signal input 15 of the channel and through the element -I 5 to the direct input of the element OR 4. In this case, a single signal appears at the output of the OR 4 element and the setup cycle occurs during the service of the request to exchange one of the information sources.

A single signal propagating through the circuit blocks the outputs of non-leading channels, but it cannot block the output of the channel that currently serves the exchange request.

After removing the exchange request signal from input 6, the signal from output 9 disappears in the same way as in the sequential polling mode. On all the single outputs of the flip-flops 10, single signals remain, and the propagation of the zero signal (polling signal) starts from the channel with the highest priority.

The invention makes it possible to significantly simplify the structure of building priority devices, reduce hardware costs by (compared with known device 4) and increase the speed of the device, which is determined only by the response time of the elements used.

In addition, the invention can operate both in the priority mode and in the sequential polling mode of information sources, without any rework in the device. The transition from one mode of operation to another is accomplished by changing the logic signal at the control input of the device, which makes it more flexible.

Claims (4)

1. USSR author's certificate number 377775, cl. G 06 F 9/18, 1970. 2. USSR Author's Certificate No. 281901, cl. G 06 F 9/18, 1969, ... „. 3 USSR author's certificate number 4 / ooo, class. G 06 F 13/00, G 06 F 9/18, 1973. 4. USSR author's certificate No. 425177, cl. G 06 F 9/18, 1972.