SU1527635A1 - Dual feed priority device - Google Patents

Abstract

A two-input priority device containing AND elements, three NOT elements, element 2I-OR-NOT, the first request input of the device connected to the first input of the AND element and the input of the first element NOT, the output of the AND element is the first information output of the device, the output of the second element NOT is the second information output of the device and is connected to the first input of the first group of inputs of element 2I-OR-NOT; the second request input of the device is connected to the second input of the first group of inputs of element 2I-OR-NOT, the output of which is connected to the input the second element NOT, characterized in that, in order to reduce the equipment, the second request input device is connected to the first input of the second group of inputs of the AND-OR-NOT element, the output of the first element is NOT connected to the second input of the second group of inputs of the II-OR-NOT element, output which is connected to the second input element And, the output of which is connected to the input of the third element NOT, the output of which is connected to the third inputs of the first and second group of inputs of the element II-OR-NOT.

Description

one

(21) 3972995 / 24-24

(22) 11/04/85

C.A%) 07. 12.89. Bul N 45

(71) Kuibyshev Institute of Railway Engineers

(72) S.L. Ivanov and G.V.Ekimov (53) 681.325 (088.8)

(56) USSR Author's Certificate No. 807296, cl. G 06 F 9/46, 1978. USSR Copyright Certificate No. 1059574, - cl. G 06 F 9/40, 1982.

(54) (57) PRIORITY DUAL INPUT DEVICE, containing AND element, three NOT elements, 2I-OR-NOT element, with the first request device input connected to the first input, AND element and the input of the first element, AND output element device information output, the output of the second element is NOT the second information output of the device and is connected to the first input of the first group of inputs of the element 2I-OR-NOT, the second request input of the device is connected to the second input of the first group of inputs of the element 2I-OR-NOT, the output of which connection n with the input of the second element is NOT different from the fact that, in order to reduce the equipment, the second request input of the device is connected to the first input of the second group of inputs of the AND-OR-NOT element, the output of the first element is NOT connected to the second input of the second group of inputs of element 2И-ШШ-НЕ, the output of which is connected to the second input of element И, the output of which is connected to the input of the third element NOT, the output of which is connected to the third inputs of the first and second group of inputs of element 2И-ИИ-НЕ.

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The invention relates to computing, in particular, to priority devices, and can be used for switching by requesting from two subscribers to a common resource.

The purpose of the invention is to reduce equipment.

The drawing shows the functional diagram of the device. ,

The bi-input priority device contains the request inputs 1 and 2, the element AND 3, the elements NOT 4-6, the element 2I-OR-NOT 7, the outputs 8 and 9.

The device works as follows.

In the initial state, the first and second request inputs 1 and 2 of the device receive Logical zero signals. The logical zero signal from input 1 of the device sets the logical zero signal at the output of the And 3 element. The logical zero signal from input 2 of the device, arriving at the corresponding inputs of the first and second groups of inputs of element 2И-OR-NOT 7, sets at its output a signal of a logical unit, which, inverting the element NOT 6, sets at output 9 of the device and the corresponding the input of the first element group

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2I-OR-NOT 7 signal logical zero. The signal of the logical unit from the output of element 2-OR-NOT 7 is fed to the second input of the element 3, allowing passage through this element of the request signal. from the first request input device 1.

If the signal of the logical unit arrives at the first input 1 of the device, and the logic zero signal remains at the input 2, then the signal of the logical unit input 1, arriving at the first input of the And 3 element, coincides with the signal of the logical unit at the second input of the same element. At its output, a logical unit signal is set to indicate the resolution of the first channel operation.

The signal of the logical unit from the input of the device, inverted by the element NOT 4, sets the signal of the logical zero at the corresponding input of the second group of inputs of the element II-OR-NOT 7.

All other inputs of the element 2I-OR-NOT 7 also have logical zero signals.

If during the operation of the first channel, the second request input 2 of the device also receives a logical unit signal, then the second channel is delayed until the first channel ends, since the logical zero signal from the input of the HE element 5 is supported at the output. element 2I- OR-NOT 7 signal of a logical unit.

After the end of the first channel operation, the signals of the logical unit are set at all inputs of the second group of inputs of element 2I-OR-NOT 7, as a result of which the logical zero signal is set at the second input of element 3 and the signal of the logical unit at output 9 of the device channel. After installing this signal, the signals of the logical unit are also set on all inputs of the first group of inputs of element 2I-OR-NOT 7, confirming the signal of a logical zero at the output of this element.

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five

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Suppose that a signal of a logical unit of zero arrives at the second input 2 of the device, 3 at the input of the device 1, then the output of element 2И-OR-NOT 7 sets the signal of logical zero, which is inverted by the element NOT 6. allows the second channel to work on the output 9 of the device.

If during the operation of the second channel the signal of the logical unit arrives at the first input of the device, then the signal of the logical unit at the output 8 of the device, meaning the first channel will work, will be issued after the second channel ends, since all three inputs of the first group the inputs of element 2I-OR- NOT 7 are set to signals of a logical unit, and, therefore, a logic zero signal is maintained at the output of this element. After resetting the signal of the logical unit at the second input 2 of the device, the signal of the logical unit is set at the output of element 2I-OR-NOT 7, thereby permitting the operation of the first channel. I

If the signals of the logical unit are simultaneously received at the inputs 1 and 2 of the device, then the operation of the first channel will be allowed first. This is due to the fact that when signals of a logical unit arrive at inputs 1 and 2 of the device at the same time, the signal at the output of element 2ИПИПЕНЕ 7 due to the physical properties of the logic elements does not have time to switch from the level of the logical unit to the level of logical zero to the output of the element 4 is set to a logical zero signal. This signal blocks the installation of the logical zero signal at the output of the 2I-OR-NE 7 element until the end of the first channel operation. After the end of the transient processes in the device, its further operation will be the same as for the case when the signal of the logical unit to the input 2 of the device arrives during the operation of the first channel.

Claims (1)

A TWO-INPUT PRIORITY DEVICE containing the AND element, the three elements NOT, the 2 AND-OR-NOT element, the first request input of the device being connected to the first input of the AND element and the input of the first element NOT, the output of the AND element being the first information output of the device, the output of the second element NOT It is the second information output of the device and is connected to the first input of the first group of inputs of the 2-OR-NOT element, the second request input of the device is connected to the second input of the first group of inputs of the 2-OR-NOT element, the output of which is connected to the input m of the second element NOT, characterized in that, in order to reduce equipment, the second request input of the device is connected to the first input of the second group of inputs of the AND-OR-NOT element, the output of the first element is NOT connected to the second input of the second group of inputs element 2 AND-OR-NOT, the output of which is connected to the second input of the element AND, the output of which is connected to the input of the third element NOT, the output of which is connected to the third inputs of the first and second group of inputs of the element 2 AND-OR-NOT.