JP2010181915A - Data input-output device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data input/output device for preventing a period of time, that is needed until input data are output, from becoming excessively long. <P>SOLUTION: The data input/output device 100 includes: a first buffer part 110; a second buffer part 120; and a path switching part 130. This buffer part 110 stores data input through the first input port, and outputs the stored data through the first output port, and deletes the data. The second buffer part 120 stores the data input through the second input port, and outputs the store data through the second port, and deletes the data. When the output of the data through the first output port is inhibited, the path switching part 130 makes the first buffer part or the second buffer part output the data input through the first input port through the second output port instead of the first output port. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a data input / output device that temporarily stores input data and outputs the stored data.

  Data input / output devices that temporarily store input data and output the stored data are known. As one of this type of data input / output device, the data input / output device described in Patent Literature 1 includes a first buffer unit and a second buffer unit.

  The first buffer unit stores data input via the first input port, and outputs the stored data via the first output port. Then, the first buffer unit erases the output data. Similarly, the second buffer unit stores data input via the second input port, and outputs the stored data via the second output port. Then, the second buffer unit erases the output data.

JP-A-5-173923

  By the way, when data is frequently output from the first output port, an external device that inputs data output from the first output port does not permit input of data output from the first output port ( May be prohibited). Therefore, in such a case, the data input / output device has a problem that it takes an excessively long time to output the data input to the data input / output device via the first input port. .

  As a result, an excessive amount of data stored in the first buffer unit may cause the first buffer unit to be unable to store new data. In this case, the processing of the external device that outputs data to the first input port may be excessively delayed.

  For this reason, an object of the present invention is to provide a data input / output device capable of solving the above-described problem “the time required until input data is output is excessively long”. is there.

In order to achieve this object, a data input / output device according to an aspect of the present invention is provided.
First buffer means for storing data input via the first input port, outputting the stored data via the first output port, and erasing the data;
Second buffer means for storing data input via the second input port, outputting the stored data via the second output port, and erasing the data;
When output of data through the first output port is prohibited, the data input through the first input port is transferred to the first buffer means or the second buffer means. Path switching means for outputting via the second output port instead of the first output port;
Is provided.

A data input / output circuit according to another embodiment of the present invention
First buffer means for storing data input via the first input port, outputting the stored data via the first output port, and erasing the data;
Second buffer means for storing data input through the second input port, outputting the stored data through the second output port, and erasing the data;
When output of data through the first output port is prohibited, the data input through the first input port is transferred to the first buffer means or the second buffer means. Path switching means for outputting via the second output port instead of the first output port;
Is provided.

In addition, a data input / output method according to another aspect of the present invention includes:
The data input through the first input port is stored in the first buffer unit, the data stored in the first buffer unit is output through the first output port, and the data is A first buffer processing step of erasing from the first buffer unit;
The data input through the second input port is stored in the second buffer unit, the data stored in the second buffer unit is output through the second output port, and the data is A second buffer processing step of erasing from the second buffer unit;
When data output through the first output port is prohibited, the data input through the first input port is replaced with the second output port instead of the first output port. Output prohibition buffer processing step to output via,
including.

Moreover, the program which is the other form of this invention is:
In the data input / output device,
The data input through the first input port is stored in the first buffer unit, the data stored in the first buffer unit is output through the first output port, and the data is First buffer processing means for erasing from the first buffer unit;
The data input through the second input port is stored in the second buffer unit, the data stored in the second buffer unit is output through the second output port, and the data is Second buffer processing means for erasing from the second buffer unit;
When data output through the first output port is prohibited, the data input through the first input port is replaced with the second output port instead of the first output port. Output prohibition buffer processing means for outputting via
It is a program for realizing.

  According to the present invention configured as described above, it is possible to avoid an excessively long time until input data is output.

It is a figure showing schematic structure in case the state of the selector part is set to the 1st state of the data input / output device concerning a 1st embodiment of the present invention. It is a figure showing the schematic structure in case the state of the selector part is set to the 2nd state of the data input / output device which concerns on 1st Embodiment of this invention. It is the flowchart which showed the process which the 1st buffer control part which concerns on 1st Embodiment of this invention performs. It is a figure showing schematic structure in case the state of the selector part is set to the 1st state of the data input / output device concerning a 2nd embodiment of the present invention. It is a figure showing schematic structure of the data input / output apparatus which concerns on the modification of embodiment of this invention.

A data input / output device according to one aspect of the present invention
First buffer means for storing data input via the first input port, outputting the stored data via the first output port, and erasing the data;
Second buffer means for storing data input through the second input port, outputting the stored data through the second output port, and erasing the data;
When output of data through the first output port is prohibited, the data input through the first input port is transferred to the first buffer means or the second buffer means. Path switching means for outputting via the second output port instead of the first output port;
Is provided.

  According to this, it can be avoided that the time required for the data input through the first input port to be output from the data input / output device is excessively long. Thereby, it is possible to avoid an excessive amount of data stored in the first buffer means. As a result, it is possible to prevent the first buffer means from newly storing data, so that it is possible to prevent an excessive delay in the processing of the external device that outputs data to the first input port. it can.

In this case, the data input / output device is
A first data amount acquisition means for acquiring the data amount stored in the first buffer means;
The route switching means is
When the acquired amount of data is larger than a first threshold value set in advance, the data input via the first input port is transferred to the first buffer means or the second buffer means. When the obtained data amount is smaller than the first threshold value, the data inputted through the first input port is sent to the first buffer means. It is preferable to be configured to output via the first output port.

  A data input / output device so that data input via the first input port is always output via the second output port when data output via the first output port is prohibited Is configured, the state where the data stored in the second buffer means cannot be output may continue.

  In such a case, the amount of data stored in the second buffer means increases to the storage capacity of the second buffer means, so that the second buffer means may not be able to store new data. is there. As a result, the processing of the external device that outputs data to the second input port may be excessively delayed.

  On the other hand, when the amount of data stored in the first buffer unit is relatively small, the possibility that the first buffer unit cannot newly store data is relatively low. That is, the possibility that the processing of the external device that outputs data to the first input port is excessively delayed is relatively low.

  Therefore, as described above, only when the amount of data stored in the first buffer means is relatively large, the data input through the first input port is output through the second output port. By configuring the data input / output device in this manner, it is possible to avoid an excessive amount of data stored in each of the first buffer means and the second buffer means.

In this case, the route switching means
The state is switched between a first state in which the second output port and the second buffer means are connected, and a second state in which the second output port and the first buffer means are connected. By including the output path switching unit and setting the state of the output path switching unit to the second state, the data stored in the first buffer unit is stored in the second buffer unit. It is preferable to be configured to output via the output port.

In another aspect of the data input / output device,
The route switching means is
The state is switched between a first state in which the second buffer means and the second input port are connected, and a second state in which the second buffer means and the first input port are connected. In addition to including the input path switching unit, by setting the state of the input path switching unit to the second state, data input via the first input port is stored in the second buffer means. It is preferable to be configured as described above.

In this case, the data input / output device is
A second data amount acquisition means for acquiring the data amount stored in the second buffer means;
The route switching means is
When the amount of data acquired by the second data amount acquisition means is smaller than a preset second threshold value, the data input via the first input port is transferred via the second output port. It is preferable to be configured to output the output.

  By the way, when the amount of data stored in the second buffer unit is relatively large, there is a relatively high possibility that the second buffer unit cannot newly store data. Therefore, as described above, only when the amount of data stored in the second buffer means is relatively small, the data input via the first input port is output via the second output port. By configuring the data input / output device in this manner, it is possible to avoid an excessive amount of data stored in each of the first buffer means and the second buffer means.

In this case, the data input / output device is
If the data amount acquired by the first data amount acquisition means is larger than a third threshold value that is larger than the first threshold value, the data amount is sent to an external device that outputs data to the first input port. It is preferable to provide a busy signal transmission means for transmitting a busy signal instructing to stop the output.

  According to this, it is possible to prevent data from being input via the first input port by the external device in a state where the first buffer means cannot store new data.

  In this case, it is preferable that the data is request data for requesting execution of processing to an external apparatus that inputs the data output from each of the first output port and the second output port.

A data input / output circuit according to another embodiment of the present invention
First buffer means for storing data input via the first input port, outputting the stored data via the first output port, and erasing the data;
Second buffer means for storing data input through the second input port, outputting the stored data through the second output port, and erasing the data;
When output of data through the first output port is prohibited, the data input through the first input port is transferred to the first buffer means or the second buffer means. Path switching means for outputting via the second output port instead of the first output port;
Is provided.

In this case, the data input / output circuit is
A first data amount acquisition means for acquiring the data amount stored in the first buffer means;
The route switching means is
When the acquired amount of data is larger than a first threshold value set in advance, the data input via the first input port is transferred to the first buffer means or the second buffer means. When the obtained data amount is smaller than the first threshold value, the data inputted through the first input port is sent to the first buffer means. It is preferable to be configured to output via the first output port.

In this case, the route switching means
The state is switched between a first state in which the second output port and the second buffer means are connected, and a second state in which the second output port and the first buffer means are connected. By including the output path switching unit and setting the state of the output path switching unit to the second state, the data stored in the first buffer unit is stored in the second buffer unit. It is preferable to be configured to output via the output port.

In another aspect of the data input / output circuit,
The route switching means is
The state is switched between a first state in which the second buffer means and the second input port are connected, and a second state in which the second buffer means and the first input port are connected. In addition to including the input path switching unit, by setting the state of the input path switching unit to the second state, data input via the first input port is stored in the second buffer means. It is preferable to be configured as described above.

In addition, a data input / output method according to another aspect of the present invention includes:
The data input through the first input port is stored in the first buffer unit, the data stored in the first buffer unit is output through the first output port, and the data is A first buffer processing step of erasing from the first buffer unit;
The data input through the second input port is stored in the second buffer unit, the data stored in the second buffer unit is output through the second output port, and the data is A second buffer processing step of erasing from the second buffer unit;
When data output through the first output port is prohibited, the data input through the first input port is replaced with the second output port instead of the first output port. Output prohibition buffer processing step to output via,
including.

In this case, the data input / output method is
Including a first data amount acquisition step of acquiring a data amount stored in the first buffer unit;
The output prohibition buffer processing step is as follows:
When the acquired amount of data is larger than a preset first threshold, data input via the first input port is output via the second output port, while the acquisition is performed It is preferable that the data input via the first input port is configured to be output via the first output port when the amount of data that is input is smaller than the first threshold value. .

In this case, the output prohibition buffer processing step is as follows.
The state is switched between a first state in which the second output port and the second buffer unit are connected, and a second state in which the second output port and the first buffer unit are connected. It is preferable that the data stored in the first buffer unit is output through the second output port by setting the state of the output path switching unit to the second state. It is.

In another aspect of the data input / output method,
The output prohibition buffer processing step is as follows:
The state is switched between a first state in which the second buffer unit and the second input port are connected and a second state in which the second buffer unit and the first input port are connected. It is preferable that data input via the first input port is stored in the second buffer unit by setting the state of the input path switching unit to the second state. is there.

Moreover, the program which is the other form of this invention is:
In the data input / output device,
The data input through the first input port is stored in the first buffer unit, the data stored in the first buffer unit is output through the first output port, and the data is First buffer processing means for erasing from the first buffer unit;
The data input through the second input port is stored in the second buffer unit, the data stored in the second buffer unit is output through the second output port, and the data is Second buffer processing means for erasing from the second buffer unit;
When data output through the first output port is prohibited, the data input through the first input port is replaced with the second output port instead of the first output port. Output prohibition buffer processing means for outputting via
It is a program for realizing.

In this case, the program is
In addition to the data input / output device,
While realizing the first data amount acquisition means for acquiring the data amount stored in the first buffer unit,
The output prohibition buffer processing means is:
When the acquired amount of data is larger than a preset first threshold, data input via the first input port is output via the second output port, while the acquisition is performed When the amount of data that is input is smaller than the first threshold, it is preferable that the data input through the first input port is output through the first output port. .

In this case, the output prohibition buffer processing means
The state is switched between a first state in which the second output port and the second buffer unit are connected, and a second state in which the second output port and the first buffer unit are connected. It is preferable that the data stored in the first buffer unit is output through the second output port by setting the state of the output path switching unit to the second state. It is.

In another aspect of the above program,
The output prohibition buffer processing means is:
The state is switched between a first state in which the second buffer unit and the second input port are connected and a second state in which the second buffer unit and the first input port are connected. It is preferable that the data input via the first input port is stored in the second buffer unit by setting the state of the input path switching unit to the second state. is there.

  Even the invention of the data input / output circuit, data input / output method, or program having the above-described configuration achieves the above-described object of the present invention because it has the same operation as the data input / output device. be able to.

  Hereinafter, embodiments of a data input / output device, a data input / output circuit, a data input / output method, and a program according to the present invention will be described with reference to FIGS.

<First Embodiment>
(Constitution)
As shown in FIG. 1, the data input / output device (data input / output circuit) 10 according to the first embodiment includes a first input port 11 and a first buffer unit (first buffer means, first buffer Buffer processing step, first buffer processing means) 12, first output port 13, first buffer control unit (part of path switching means, first data amount acquisition means, first data amount acquisition) Process, busy signal transmission means) 14, a second input port 15, a second buffer unit (second buffer means, second buffer processing step, second buffer processing means) 16, a second An output port 17, a second buffer control unit (a part of the path switching unit, a second data amount acquisition unit) 18, and a selector unit (an output path switching unit, a part of the path switching unit) 19 are provided. .

  A first input-side external device 21 is connected to the first input port 11. A second input side external device 22 is connected to the second input port 15. An output-side external device 31 is connected to each of the first output port 13 and the second output port 17.

  The first input-side external device 21 is a circuit (LSI (Large Scale Integration) or the like) or a device (processing device, storage device, input / output device or the like). The first input side external device 21 outputs data to the first input port 11. In this example, this data is request data for requesting the output side external device 31 to execute processing. The size (data amount) of this data is 1 word (for example, 32 bits).

  The second input side external device 22 has a configuration similar to that of the first input side external device 21. That is, the second input side external device 22 also outputs data to the second input port 15 in the same manner as the first input side external device 21.

  The output-side external device 31 is a circuit (LSI or the like) or a device (processing device, storage device, input / output device or the like). The output-side external device 31 prohibits the output of data via the first output port 13 according to the processing load executed by the output-side external device 31 (for example, to the first output port 13 Send a busy signal to stop data output). Similarly, the output-side external device 31 prohibits data output via the second output port 17 according to the processing load executed by the output-side external device 31.

  The first buffer unit 12 includes a flip-flop circuit. The first buffer unit 12 is configured to be able to store a plurality (32 in this example) of data. That is, the storage capacity of the first buffer unit 12 is 32 words (1024 bits).

  The first buffer unit 12 stores data input by the first input-side external device 21 via the first input port 11. The first buffer unit 12 reads only one stored data at a predetermined timing (every time a predetermined output cycle elapses in this example), and reads the read data to the first output port 13. To the output-side external device 31. Further, the first buffer unit 12 erases the output data.

  The first buffer control unit 14 acquires the amount of data stored in the first buffer unit 12. In this example, the first buffer control unit 14 holds a first counter value indicating the number of data stored in the first buffer unit 12.

  Then, each time the first buffer unit 12 stores the input data, the first buffer control unit 14 sets the held first counter value to “1” as the first counter value. Update to the added value. Further, every time data is erased from the first buffer unit 12, the first buffer control unit 14 subtracts “1” from the held first counter value and the first counter value. Update to value.

  That is, the first counter value held by the first buffer control unit 14 represents the amount of data stored in the first buffer unit 12.

  Further, the first buffer control unit 14 indicates that the output of data to the first input side external device 21 is stopped when the held first counter value is larger than a preset busy threshold. Send a busy signal to indicate. Note that the first counter value held by the first buffer control unit 14 is larger than the busy threshold value that the data amount stored in the first buffer unit 12 is larger than the third threshold value. It corresponds to.

  The second buffer unit 16 has the same configuration as the first buffer unit 12. That is, the second buffer unit 16 stores data input by the second input-side external device 22 via the second input port 15. The second buffer unit 16 reads only one stored data at a predetermined timing, and outputs the read data to the output side external device 31 via the second output port 17. Further, the second buffer unit 16 erases the output data.

  The second buffer control unit 18 has the same configuration as the first buffer control unit 14. That is, the second buffer control unit 18 acquires the amount of data stored in the second buffer unit 16. In this example, the second buffer control unit 18 holds a second counter value representing the number of data stored in the second buffer unit 16.

  Then, every time the second buffer unit 16 stores the input data, the second buffer control unit 18 sets the held second counter value to “1” as the second counter value. Update to the added value. Further, every time data is erased from the second buffer unit 16, the second buffer control unit 18 subtracts the held second counter value from the second counter value by “1”. Update to value.

  That is, the second counter value held by the second buffer control unit 18 represents the amount of data stored in the second buffer unit 16.

  The second buffer control unit 18 is also instructed to stop the output of data to the second input side external device 22 when the second counter value held is larger than the busy threshold. Send a signal.

  The selector unit 19 connects the second output port 17 and the second buffer unit 16, and disconnects the second output port 17 and the first buffer unit 12. The state is switched to a second state in which the port 17 and the first buffer unit 12 are connected and the second output port 17 and the second buffer unit 16 are disconnected.

  Further, the first buffer control unit 14 holds the first buffer control unit 14 when the output-side external device 31 prohibits the output of data via the first output port 13. It is determined whether or not the counter value is greater than a preset first switching threshold value. Note that the fact that the first counter value is larger than the first switching threshold value corresponds to the fact that the amount of data stored in the first buffer unit 12 is larger than the first threshold value. In the present example, the first switching threshold is set to a value smaller than the busy threshold.

  If the first buffer control unit 14 determines that the first counter value is larger than the first switching threshold, the first buffer control unit 14 acquires the second counter value held in the second buffer control unit 18. Then, the first buffer control unit 14 determines whether or not the acquired second counter value is smaller than a preset second switching threshold value. Note that the fact that the second counter value is smaller than the second switching threshold value corresponds to the fact that the amount of data stored in the second buffer unit 16 is smaller than the second threshold value.

  If the first buffer control unit 14 determines that the second counter value is smaller than the second switching threshold, the first buffer control unit 14 sets the state of the selector unit 19 to the second state (see FIG. 2). As a result, the first buffer unit 12 reads only one stored data at a predetermined timing, and outputs the read data to the output-side external device 31 via the second output port 17. Further, the first buffer unit 12 erases the output data.

  That is, in this case, the first buffer control unit 14 transfers the data input via the first input port 11 to the first buffer unit 12 instead of the first output port 13 to the second output. It can be said that the output is made to the output side external device 31 via the port 17.

  On the other hand, when the output-side external device 31 does not prohibit the output of data via the first output port 13, the first buffer control unit 14 has the first counter value equal to or less than the first switching threshold value. Or when it is determined that the second counter value is greater than or equal to the second switching threshold, the state of the selector unit 19 is set to the first state (see FIG. 1). Accordingly, the first buffer unit 12 reads only one stored data at a predetermined timing, and outputs the read data to the output-side external device 31 via the first output port 13. Further, the first buffer unit 12 erases the output data.

(Operation)
Next, the operation of the data input / output device 10 described above will be specifically described.
The first buffer control unit 14 executes the process shown by the flowchart in FIG. 3 every time the output cycle elapses. This processing corresponds to the buffer processing step when output is prohibited.

  Specifically, the first buffer control unit 14 determines in step 305 whether or not data output from the first output port 13 is prohibited.

  Assume that data output from the first output port 13 is not prohibited. In this case, the first buffer control unit 14 determines “No”, proceeds to step 310, and sets the state of the selector unit 19 to the first state.

  As a result, the first buffer unit 12 outputs the stored data to the output-side external device 31 via the first output port 13. Further, the second buffer unit 16 outputs the stored data to the output side external device 31 via the second output port 17.

Then, in step 315, the first buffer control unit 14 determines whether or not the first counter value is larger than the busy threshold value.
Assume that the first counter value is equal to or less than the busy threshold. In this case, the first buffer control unit 14 ends the process illustrated by the flowchart of FIG. 3 without transmitting a busy signal.

Next, the description will be continued assuming that the output of data from the first output port 13 is prohibited and the first counter value is equal to or smaller than the first switching threshold value.
In this case, the first buffer control unit 14 determines “Yes” in Step 305 and proceeds to Step 320. Then, the first buffer control unit 14 determines whether or not the held first counter value is larger than the first switching threshold value.

  According to the above assumption, the first buffer control unit 14 determines “No”, proceeds to step 310, and sets the state of the selector unit 19 to the first state in the same manner as described above.

  Next, when data output from the first output port 13 is prohibited, the first counter value is larger than the first switching threshold, and the second counter value is the second value. The description will be continued assuming that the switching threshold is exceeded.

  In this case, the first buffer control unit 14 determines “Yes” in step 305 and step 320 and proceeds to step 325. Then, the first buffer control unit 14 determines whether or not the second counter value held by the second buffer control unit 18 is smaller than the second switching threshold value.

  According to the above assumption, the first buffer control unit 14 determines “No”, proceeds to step 310, and sets the state of the selector unit 19 to the first state in the same manner as described above.

  Next, when data output from the first output port 13 is prohibited, the first counter value is larger than the first switching threshold, and the second counter value is the second value. The description will be continued on the assumption that the switching threshold is smaller.

  In this case, the first buffer control unit 14 determines “Yes” in step 305, step 320, and step 325, and proceeds to step 330. Then, the first buffer control unit 14 sets the state of the selector unit 19 to the second state.

  As a result, the first buffer unit 12 outputs the stored data to the output side external device 31 via the second output port 17. Further, the second buffer unit 16 does not output stored data.

Further, a case where the first counter value becomes larger than the busy threshold due to the increase in the first counter value will be described.
In this case, the first buffer control unit 14 determines “Yes” in step 315, proceeds to step 335, and transmits a busy signal to the first input-side external device 21.

  As a result, the first input-side external device 21 stops outputting data to the first input port 11. As a result, it is possible to prevent data from being input via the first input port 11 by the first input-side external device 21 in a state where the first buffer unit 12 cannot newly store data. Can do.

  As described above, according to the first embodiment of the data input / output device of the present invention, the time required for the data input through the first input port 11 to be output from the data input / output device 10 is described. Can be prevented from becoming excessively long. Thereby, it is possible to avoid an excessive amount of data stored in the first buffer unit 12. As a result, it is possible to prevent the first buffer unit 12 from newly storing data, so that the processing of the first input-side external device 21 that outputs data to the first input port 11 is excessive. Delays can be prevented.

  By the way, when the output of data through the first output port 13 is prohibited, the data input through the first input port 11 is always output through the second output port 17. If the data input / output device is configured, the state where the data stored in the second buffer unit 16 cannot be output may continue.

  In such a case, when the amount of data stored in the second buffer unit 16 increases to the storage capacity of the second buffer unit 16, the second buffer unit 16 can newly store data. There is a risk of disappearing. As a result, the processing of the second input side external device 22 that outputs data to the second input port 15 may be excessively delayed.

  On the other hand, when the amount of data stored in the first buffer unit 12 is relatively small, the possibility that the first buffer unit 12 cannot newly store data is relatively low. That is, the possibility that the processing of the first input side external device 21 that outputs data to the first input port 11 is excessively delayed is relatively low.

  Therefore, as in the first embodiment, only when the amount of data stored in the first buffer unit 12 is relatively large, the data input via the first input port 11 is output to the second output. By configuring the data input / output device 10 to output via the port 17, it is possible to avoid an excessive amount of data stored in each of the first buffer unit 12 and the second buffer unit 16. be able to.

  Further, when the amount of data stored in the second buffer unit 16 is relatively large, there is a relatively high possibility that the second buffer unit 16 cannot newly store data. Therefore, as in the first embodiment, only when the amount of data stored in the second buffer unit 16 is relatively small, the data input through the first input port 11 is output as the second output. By configuring the data input / output device 10 to output via the port 17, it is ensured that the amount of data stored in each of the first buffer unit 12 and the second buffer unit 16 will be excessive. It can be avoided.

<Second Embodiment>
Next, a data input / output device according to a second embodiment of the invention will be described. The data input / output device according to the second embodiment is different from the data input / output device according to the first embodiment in that a selector unit is provided between the second input port and the second buffer unit. Is different. Accordingly, the following description will focus on such differences.

  As shown in FIG. 4, the data input / output device 10 according to the second embodiment replaces the selector unit 19 according to the first embodiment with a selector unit (input path switching unit, part of path switching means). 19A is provided.

  The selector unit 19A includes a first state in which the second buffer unit 16 and the second input port 15 are connected and the second buffer unit 16 and the first input port 11 are blocked, and a second buffer The state is switched to a second state in which the unit 16 and the first input port 11 are connected and the second buffer unit 16 and the second input port 15 are disconnected.

  When the same condition as in the first embodiment is satisfied (that is, when “Yes” is determined in all of step 305, step 320, and step 325), the first buffer control unit 14 determines that the selector 19A Set the state to the second state.

In this state, when the first input-side external device 21 outputs data to the first input port 11, the second buffer unit 16 stores the data input via the first input port 11. . That is, in this case, it can be said that the first buffer control unit 14 stores the data input via the first input port 11 in the second buffer unit 16.
On the other hand, the first buffer unit 12 does not store this data.

  On the other hand, the first buffer control unit 14 changes the state of the selector unit 19A when the above condition is not satisfied (that is, when “No” is determined in any of Step 305, Step 320, and Step 325). Set to the first state. In this state, when the first input-side external device 21 outputs data to the first input port 11, the first buffer unit 12 stores the data input via the first input port 11. .

  This second embodiment can also achieve the same effects as the first embodiment.

  In addition, this invention is not limited to said each embodiment, A various modification can be employ | adopted within the scope of the present invention. For example, in each of the above embodiments, the data input / output device includes two circuit units each including an input port, a buffer unit, and an output port. However, the data input / output device includes three or more such circuit units. May be.

  In this case, the data input / output device is a set of two circuit units configured so that two output ports can be switched and used as an output port for outputting data input through one input port. A plurality may be provided.

  In each of the above embodiments, two output ports can be switched and used as an output port for outputting data input through one input port. However, three or more output ports are used. It may be configured to be able to be used by switching.

  In each of the above embodiments, each function of the data input / output device 10 is realized by hardware such as a circuit. By the way, the data input / output device 10 includes a processing device and a storage device that stores a program (software), and is configured so that each function is realized by the processing device executing the program. Also good.

  Further, as shown in FIG. 5, the data input / output device 100 according to the modification of each of the above embodiments includes a first buffer unit (first buffer means) 110 and a second buffer unit (second buffer unit). A buffer unit) 120 and a path switching unit (path switching unit) 130.

The first buffer unit 110 stores data input via the first input port, outputs the stored data via the first output port, and deletes the data.
The second buffer unit 120 stores data input via the second input port, outputs the stored data via the second output port, and deletes the data.

  When the output of data through the first output port is prohibited, the path switching unit 130 converts the data input through the first input port into the first buffer unit 110 or the second buffer unit. 120 is output via the second output port instead of the first output port.

This modification can also achieve the same effects as the above embodiments.
In addition, as another modified example of the above-described embodiment, any combination of the above-described embodiments and modified examples may be employed.

  The present invention can be applied to a data input / output device that temporarily stores input data and outputs the stored data.

DESCRIPTION OF SYMBOLS 10 Data input / output device 11 1st input port 12 1st buffer part 13 1st output port 14 1st buffer control part 15 2nd input port 16 2nd buffer part 17 2nd output port 18 2nd 2 buffer control unit 19 selector unit 19A selector unit 21 first input side external device 22 second input side external device 31 output side external device 100 data input / output device 110 first buffer unit 120 second buffer unit 130 Route switching unit

Claims (19)

A data input / output device,
First buffer means for storing data input via the first input port, outputting the stored data via the first output port, and erasing the data;
Second buffer means for storing data input through the second input port, outputting the stored data through the second output port, and erasing the data;
When the output of data through the first output port is prohibited, the data input through the first input port is transferred to the first buffer means or the second buffer means. Path switching means for outputting via the second output port instead of the first output port;
A data input / output device. The data input / output device according to claim 1,
A first data amount acquisition means for acquiring the amount of data stored in the first buffer means;
The route switching means is
When the acquired data amount is larger than a preset first threshold value, the data input via the first input port is input to the first buffer means or the second buffer means. When the obtained data amount is smaller than the first threshold value, the data inputted through the first input port is sent to the first buffer means. A data input / output device configured to output via the first output port. The data input / output device according to claim 1 or 2,
The route switching means is
The state is switched between a first state in which the second output port and the second buffer means are connected, and a second state in which the second output port and the first buffer means are connected. By including the output path switching unit and setting the state of the output path switching unit to the second state, the data stored in the first buffer unit is stored in the second buffer unit. A data input / output device configured to output via the output port. The data input / output device according to claim 1 or 2,
The route switching means is
The state is switched between a first state in which the second buffer means and the second input port are connected, and a second state in which the second buffer means and the first input port are connected. In addition to including the input path switching unit, by setting the state of the input path switching unit to the second state, data input via the first input port is stored in the second buffer means. Data input / output device configured as follows. A data input / output device according to any one of claims 1 to 4,
A second data amount acquisition means for acquiring a data amount stored in the second buffer means;
The route switching means is
When the data amount acquired by the second data amount acquisition means is smaller than a preset second threshold value, the data input via the first input port is transferred via the second output port. A data input / output device configured to be output. A data input / output device according to any one of claims 1 to 5,
If the amount of data acquired by the first data amount acquisition means is greater than a third threshold value that is greater than the first threshold value, the data is sent to an external device that outputs data to the first input port. A data input / output device comprising busy signal transmission means for transmitting a busy signal instructing to stop output. A data input / output device according to any one of claims 1 to 6,
The data is a data input / output device that is request data for requesting an external device that inputs the data output from each of the first output port and the second output port to execute processing. A data input / output circuit,
First buffer means for storing data input via the first input port, outputting the stored data via the first output port, and erasing the data;
Second buffer means for storing data input through the second input port, outputting the stored data through the second output port, and erasing the data;
When the output of data through the first output port is prohibited, the data input through the first input port is transferred to the first buffer means or the second buffer means. Path switching means for outputting via the second output port instead of the first output port;
A data input / output circuit comprising: A data input / output circuit according to claim 8,
A first data amount acquisition means for acquiring the amount of data stored in the first buffer means;
The route switching means is
When the acquired data amount is larger than a preset first threshold value, the data input via the first input port is input to the first buffer means or the second buffer means. When the obtained data amount is smaller than the first threshold value, the data inputted through the first input port is sent to the first buffer means. A data input / output circuit configured to output via the first output port. The data input / output circuit according to claim 8 or 9,
The route switching means is
The state is switched between a first state in which the second output port and the second buffer means are connected, and a second state in which the second output port and the first buffer means are connected. By including the output path switching unit and setting the state of the output path switching unit to the second state, the data stored in the first buffer unit is stored in the second buffer unit. A data input / output circuit configured to output via the output port. The data input / output circuit according to claim 8 or 9,
The route switching means is
The state is switched between a first state in which the second buffer means and the second input port are connected, and a second state in which the second buffer means and the first input port are connected. In addition to including the input path switching unit, by setting the state of the input path switching unit to the second state, data input via the first input port is stored in the second buffer means. A data input / output circuit configured as described above. A data input / output method,
The data input through the first input port is stored in the first buffer unit, the data stored in the first buffer unit is output through the first output port, and the data is A first buffer processing step of erasing from the first buffer unit;
The data input through the second input port is stored in the second buffer unit, the data stored in the second buffer unit is output through the second output port, and the data is A second buffer processing step of erasing from the second buffer unit;
When data output through the first output port is prohibited, the data input through the first input port is replaced with the second output port instead of the first output port. Output prohibition buffer processing step to output via,
Data input / output method including A data input / output method according to claim 12,
Including a first data amount acquisition step of acquiring a data amount stored in the first buffer unit;
The output prohibition buffer processing step includes:
When the acquired amount of data is larger than a preset first threshold value, data input via the first input port is output via the second output port, while the acquisition is performed A data input / output method configured to output data input via the first input port via the first output port when the amount of data input is smaller than the first threshold. A data input / output method according to claim 12 or claim 13,
The output prohibition buffer processing step includes:
The state is switched between a first state in which the second output port and the second buffer unit are connected and a second state in which the second output port and the first buffer unit are connected. Data input / output configured to output the data stored in the first buffer unit via the second output port by setting the state of the output path switching unit to the second state Method. A data input / output method according to claim 12 or claim 13,
The output prohibition buffer processing step includes:
The state is switched between a first state in which the second buffer unit and the second input port are connected, and a second state in which the second buffer unit and the first input port are connected. A data input / output method configured to store data input via the first input port in the second buffer unit by setting the state of the input path switching unit to the second state . In the data input / output device,
The data input through the first input port is stored in the first buffer unit, the data stored in the first buffer unit is output through the first output port, and the data is First buffer processing means for erasing from the first buffer unit;
The data input through the second input port is stored in the second buffer unit, the data stored in the second buffer unit is output through the second output port, and the data is Second buffer processing means for erasing from the second buffer unit;
When data output through the first output port is prohibited, the data input through the first input port is replaced with the second output port instead of the first output port. Output prohibition buffer processing means for outputting via
A program to realize The program according to claim 16, wherein
In addition to the data input / output device,
Realizing a first data amount acquisition means for acquiring the data amount stored in the first buffer unit;
The output prohibition buffer processing means includes:
When the acquired amount of data is larger than a preset first threshold value, data input via the first input port is output via the second output port, while the acquisition is performed A program configured to output data input via the first input port via the first output port when the amount of data input is smaller than the first threshold. A program according to claim 16 or claim 17, wherein
The output prohibition buffer processing means includes:
The state is switched between a first state in which the second output port and the second buffer unit are connected and a second state in which the second output port and the first buffer unit are connected. A program configured to output data stored in the first buffer unit via the second output port by setting the state of the output path switching unit to the second state. A program according to claim 16 or claim 17, wherein
The output prohibition buffer processing means includes:
The state is switched between a first state in which the second buffer unit and the second input port are connected, and a second state in which the second buffer unit and the first input port are connected. A program configured to store data input via the first input port in the second buffer unit by setting the state of the input path switching unit to the second state.

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