JPH07123324A - Controller for video signal switch - Google Patents

Abstract

PURPOSE:To make a tally signal outputted from an interface part to the outside always match with a control signal outputted from a switcher part to a cross point element. CONSTITUTION:A counter 11 counts from '1' to N during a vertical fly-back period. The output of the counter is transmitted through an OR circuit 12 to an output control data bus 26 and inputted to decoders 13 and 32. The decoders 13 and 32 decode the inputted value of the counters and respectively output the results to latch holding circuits 14 and 34. Therefore, the latch holding circuits 14 and 34 are successively operated from the first column to the Nth column at the same time for each column. Thus, the latch holding circuit 34 latches the control signal outputted to the cross point element, and the latch holding circuit 14 latches the control signal held at the latch holding circuit 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal switch controller, and more particularly to a video signal switch controller used in a television studio transmission system.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional video signal switch controller has an interface section 21 and a switch section 22 connected to the interface section through a plurality of buses. The interface unit 21 includes N latch / hold circuits 23 for latching control data of the first to Nth columns input from the outside with the first to Nth strobe signals, respectively, and the first to Nth strobe signals. A prioritized encoder circuit 24 for encoding the following, a latch circuit 25 for latching the output of the prioritized encoder circuit 24,
A decoding circuit 27 that decodes the data output from the latch circuit 25 to the output control data bus 26, and, in response to the output of the decoder 27, sends the data latched by the latch / hold circuit 23 to the input / output control data bus 28. Comparing circuit 3 for comparing the data sent to the input / output control data bus 28 with the tally data input from the switching unit 22 and resetting the latch circuit 25.
It has 0 and.

The switching unit 22 includes an output control data bus 26.
Circuit 31 for decoding the data output to
And N latch / hold circuits 32 for respectively latching the control data of the first to Nth columns from the input / output control data bus 28 in response to the output of the decode circuit 31, and also responding to the output of the decode circuit 31. Latch / hold circuit 32
It has a buffer circuit 34 for outputting the data latched in step 1 to tally data bus 33 as tally data.
The N latch / hold circuits 32 are connected to the control terminals of N column cross-point elements (not shown) for switching the video signals.

Next, the operation of the control device for the video signal switching device will be described. When the switching operation is not performed, the interface section 21 outputs the control signal held by the latch / hold circuit 23 to the outside as a tally signal. Further, in the switch unit 22, the control signal held in the latch / hold circuit 32 is output to the crosspoint element. That is, in this video signal switch controller,
It is possible to externally monitor what kind of control signal is supplied to the first to Nth crosspoint elements.

Next, the switching operation will be described. In addition,
This switching operation is performed within a period other than the vertical blanking period of the video signal input to the crosspoint element. First, the control data input for each column is latched by the latch / data holding circuit 23 by the strobe signal. The control data latched by the latch / hold circuit 23 is output to the outside as a tally signal and also to the buffer circuit 29. At the same time, the strobe signals are coded by the priority encoder circuit 24 in the order of higher priority, latched by the latch circuit 25 and output to the output control data bus 26. The decode circuit 27 uses the output control data bus 2
The buffer circuit 29 decodes the data output to
Open the gate. In this way, the control data of the column having the highest priority among the columns to which the strobe signal is input, for example, the nth column, is sent to the input / output control data bus 28.

In the switch unit 22, the output control data bus 2
The data from 6 is decoded by the decode circuit 31 and output to the latch / hold circuit 32 and the buffer circuit 34. As a result, the latch / hold circuit 31 (on the nth column) corresponding to the column that has output data to the input / output control bus data 28 latches the control data from the input / output control bus data 28. The data latched by the latch / hold circuit 31 is output to the control terminal of the cross point element in the n-th column, and also the tally data bus 33 is passed through the buffer circuit 34.
Is output to.

The data output from the interface section 21 to the input / output control data bus 28 is also input to the comparison circuit 30. Also, from the switching unit 22 to the tally data bus 3
The data output to 3 is also input to the comparison circuit 30. The comparison circuit 30 compares both data, and when they match, outputs a reset signal to reset the latch circuit 25. One switching control is completed by the above operation.

In an actual video signal switching device control device, one interface unit 21 corresponding to N columns of control signals, and L corresponding to M (N ≧ M) columns of control signals.
The (N ≦ L × M) switch units 22 are connected by a bus corresponding to N columns of control signals.

[0009]

In the conventional control device for a video signal switching device, the control data input to the interface section is output to the outside as a tally signal according to the strobe signal. The control signal output from the switch unit is input to the comparator via the tally data bus and compared with the control signal output from the interface unit. That is, in this video signal switch control device, the control signal output from the interface unit and the control signal output from the switch unit to the crosspoint element are collated only immediately after the switching operation is performed. As described above, in the conventional video signal switch controller, after the switching operation is completed, the tally signal output from the interface 21 to the outside and the control signal output from the switch unit 22 to the crosspoint element are output. There is no comparison. Therefore, the latch / hold circuit 23 of the interface 21 and the switching unit 22
Of the holding data of the latch / holding circuit 31 of the interface 21 and the holding / holding circuit 31 of the switching unit 22 by exchanging the switching unit 22. There is a case where the tally signal output from the interface 21 to the outside does not match the control signal output from the switching unit 22 to the crosspoint element due to a difference in data.

It is an object of the present invention to provide a video signal switch control device in which a tally signal output from the interface section to the outside and a control signal output from the switch section to the crosspoint element always match.

[0011]

According to the present invention, there is provided an interface section having first to Nth input terminals and a switching section having first to Nth control terminals. And the switch unit are connected to the bus line by a bus line to supply the control signal input to the n-th (1≤n≤N) input terminal to the n-th control terminal. In the switching unit, the first
1st to Nth holding means for holding the control signals supplied to the Nth to Nth control terminals, respectively, and a tally signal for outputting the control signals output from the first to Nth holding means to the interface section. Is provided to the outside as a first to Nth output means, and the first to Nth holding means and the first to Nth output means are connected by a tally bus to be supplied to the nth control terminal. A control device for a video signal switching device is obtained in which the control signal is output from the n-th output means to the outside.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention. Here, the same parts as those of the related art are designated by the same reference numerals and the description thereof will be omitted.

The interface unit 21 of the control device for the video signal switch according to the present embodiment is provided with a fixed period within the vertical blanking period.
Vertical blanking interval counter 11 that counts from 1 to N
And an output of the encoder circuit 24 with priority and an output of the vertical blanking interval counter 11 and outputs the logical sum to the output control data bus 26, and the logical output to the output control data bus 26. It has a decode circuit 13 for decoding the sum signal, and N latch / hold circuits 14 that output the data sent from the tally data bus 33 according to the output of the decode circuit 13 as a tally signal to the outside. The interface unit 21 is the latch / hold circuit 2 included in the conventional interface unit 21.
3 does not have.

The switch unit 22 has the same structure as the conventional one, but the decode circuit 31 includes an output control data bus 2
The output of the OR circuit 12 is input via 6 and the output of the buffer circuit 34 is connected to be output to the latch / hold circuit 14 via the tally data bus 33.

Next, the operation of the video signal switch controller of the present embodiment will be described. First, the control data externally input for each of the first to Nth columns is input to the buffer circuit 29. In addition, the strobe signals input from the outside for each of the first to Nth columns are coded by the priority-ordered encoder 24 in accordance with the priority order. Prioritized encoder 2
The strobe signal coded by 4 is applied to the decoding circuit 2
It is decoded at 7 and input to the buffer circuit 29. The buffer circuit 29 opens the gate according to the strobe signal from the decoding circuit 27 and sends the input control data to the input / output control data bus 28. In this way, the control data selected in descending order of priority is sent to the input / output control data bus 28. Also, the encoder with priority 2
The strobe signal coded by 4 is the OR circuit 12
Entered in. The logical sum circuit calculates the logical sum of the coded strobe signal and the count value of the vertical blanking interval counter 11. However, during the period in which the switching operation is performed (the period other than the vertical blanking period), the vertical blanking period counter 11
Is stopped, the result is that the OR circuit 12
Outputs the coded strobe signal as it is to the output control data bus 26.

In the switch unit 22, the output control data bus 2
The signal from 6 is decoded by the decode circuit 31, and the decoded signal is output to the latch / hold circuit 32 and the buffer circuit 34. Then, the control data sent via the input / output control data bus 28 is latched by the latch / holding circuit 31 in accordance with the output of the decoding circuit 31, and is output to the control terminal of the crosspoint element. The buffer circuit 34 also outputs the control data latched by the latch / hold circuit 32 to the tally data bus 33.

On the other hand, in the interface section 21, the signal outputted to the output control data bus 26 is decoded by the decoding circuit 1.
3 is decoded and input to the latch / hold circuit 14. Therefore, the control data output from the buffer circuit 34 to the tally data bus 33 is latched by the latch / hold circuit 14 in the same column as the switching unit 22 side and output to the outside as a tally signal.

The switching operation is prohibited within the vertical blanking period. Then, within a predetermined fixed period within this vertical blanking period, the vertical blanking period counter 11
Count from to N. The counted value is input to the logical sum circuit 12. At this time, since the decoder 24 has stopped operating, the logical sum circuit 12 sequentially outputs the count values from 1 to N to the output control data bus 26. The count value output to the output control data bus 26 is decoded by the decode circuit 13 and the decode circuit 31. The count value decoded by the decoding circuit 13 is output to the latch / holding circuit 14, and the decoding circuit 3
The count value decoded in 1 is stored in the latch / hold circuit 3
4 is output. As a result, the data held in the latch / hold circuits 34 from the first column to the N-th column are sequentially output to the latch / hold circuits 14, and all the latch / hold circuits 34 are held.
The data held by is held in the latch / hold circuit 14.

In this way, in the present embodiment, the data held in the latch / hold circuit 14 is updated periodically even if there is no switching operation, so that the switching unit 22 outputs the data to the crosspoint element. It is possible to always match the control data that is output with the tally signal that is output from the interface unit 21 to the outside.

[0020]

According to the present invention, first to N-th holding means for holding the control signals supplied to the first to N-th control terminals respectively in the switching section, and the first to N-th holding sections in the interface section. First to Nth output means for outputting the control signal output from the Nth holding means to the outside as a tally signal are provided, and the first to Nth holding means and the first to Nth output means are provided in a tally bus. By connecting with, the control signal actually supplied to the control terminal can be confirmed externally.

Further, according to the present invention, the interface section is provided with counting means for counting from 1 to N and outputting the count value, and the interface section and the switching section respectively decode the count values from the counting means. By providing the first to Nth output means and the decoding means for outputting the clock signal to the first to Nth holding means, the first to the Nth based on the control signals held by the first to Nth holding means. The content of the data output to the outside by the Nth output means can be periodically updated.

Further, according to the present invention, by providing a logical sum circuit for obtaining a logical sum of the output of the counting means and the strobe signal, and treating the output of the counting means in the same manner as the strobe signal, the circuit configuration is improved. Without complicating
The control signal supplied to the control terminal and the tally signal output to the outside can always be matched.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional control device for a video signal switching device.

[Explanation of symbols]

 11 vertical blanking period counter 12 OR circuit 13 decoding circuit 14 latch / holding circuit 21 interface section 22 switcher section 23 latch / holding circuit 24 priority encoder circuit 25 latch circuit 26 output control data bus 27 decoding circuit 28 input / output Control data bus 29 Buffer circuit 30 Comparison circuit 31 Latch / hold circuit 32 Decode circuit 33 Tally data bus 34 Buffer circuit

Claims (3)

[Claims] 1. An interface section having first to Nth input terminals and a switching section having first to Nth control terminals, wherein the interface section and the switching section are connected by a bus line. The n-th (1 ≦ n ≦ N)
In the control device for the video signal switching device, which supplies the control signal input to the input terminal to the nth control terminal,
The switching section is provided with first to Nth holding means for respectively holding the control signals supplied to the first to Nth control terminals, and the interface section outputs from the first to Nth holding means. First to Nth output means for outputting the controlled signal to the outside as a tally signal are provided, and the first to Nth holding means and the first to Nth output means are connected by a tally bus. A control device for a video signal switch, wherein a control signal supplied to an n control terminal is output from the nth output means to the outside. 2. The interface unit counts from 1 to N and outputs a count value; and a count unit which decodes the count value and which corresponds to the count value among the first to Nth output units. a first decoding means for outputting a clock signal to the n output means, and the switching unit decodes the count value to output the first to Nth output values.
2. The video signal switch controller according to claim 1, further comprising a second decoding means for outputting a clock signal to the n-th holding means corresponding to the count value among the holding means. 3. The interface unit is connected to the first to Nth input terminals, respectively, and is connected to the bus line, and is responsive to the first to Nth strobe signals in response to the first to Nth strobe signals. First to Nth latch / hold circuits for latching the control signals respectively input to the input terminals, and a prioritized encoder for encoding the first to Nth strobe signals according to a predetermined priority order, A decoder that decodes the strobe signal encoded by the priority encoder and outputs the decoded strobe signal to the first to Nth latch / hold circuits, and the logical sum of the output of the priority encoder and the output of the counting means. 3. The video according to claim 2, further comprising: a logical sum circuit that calculates and outputs the calculated logical sum to the first decoding unit and the second decoding unit. Control device for signal switch.