JP2001111936A - Data input output device and data input output method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the operability at start of recording and reproduction and at switching such as reversing the reproduction direction and high-speed reproduction. SOLUTION: An AV server system consists of a data storage device, input output ports for input output of AV data, and a system controller or the like. The system controller uses a time slot to control access timing of each input output port in time division. Each input output port issues as application of using the time slot when the input output port is accessible to the data storage device. When receiving the application of use from a port with the highest priority over the time slot, the system controller approves the use of the time slot by this port without fail. When the system controller receives an application of use of a time slot from a port whose data speed is changed, the system controller approves its application, when receiving no application of use of a time slot from a port whose data speed is changed, the system controller approves the application of use of a times slot by a port whose input output data speed is constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data input / output device and a data input / output device used for a server system such as an AV server system for recording and reproducing a plurality of data in parallel, for example, storing AV (audio and / or video) data. It relates to an input / output method.

[0002]

2. Description of the Related Art An AV server system for storing, reproducing, editing, and distributing AV (audio and / or video) data includes a data storage device such as a hard disk array for storing AV data. A
It comprises a plurality of AV data input / output interfaces (hereinafter, referred to as ports) for inputting / outputting V data, a system controller for controlling the entire system, and the like. Each port includes a memory or the like for adjusting timing when outputting AV data from the data storage device or when inputting AV data to the data storage device. In the AV server system, the system controller controls the access timing of each port to the data storage device so as to use these ports evenly and time-divisionally at a fixed cycle, thereby realizing simultaneous parallel processing with multiple channels. Was. Such AV
In the server system, an allocation time (hereinafter, referred to as a time slot) to be assigned to a port of each channel is periodically determined, and when the time slot comes, the port of each channel accesses the data storage device.

[0003] This time slot breaks down when data is input / output at a constant speed from a time slot assigned to a port of a certain channel to the next time slot assigned to itself. The time width is set so that data of a data amount that does not cause the recording can be recorded or reproduced within that time. That is,
The time slot allocated to a certain port occurs almost periodically, but the time width of the time slot and one slot period are determined so that the continuity of data input / output to / from the outside is not interrupted. Further, the time slot is generally set to a not so large time width so that the amount of memory provided in each port becomes as small as possible and the response of the system is improved.

Here, there are the following first and second time slot allocation methods in a conventional AV server system having four ports (channel 1 to channel 1).
Will be described.

First, a first time slot allocation method will be described with reference to FIG.

[0006] In the first time slot allocation method, one slot period composed of the same number of time slots as the number of ports of the AV server system is determined. Here, since the number of ports is four, one slot period composed of four time slots is determined. Each time slot constituting one slot period is assigned a slot number. Here, slot numbers # 1 to # 4 are assigned.

In the first time slot allocation method, each port is allocated to each time slot in one slot cycle in a one-to-one relationship, and each port is assigned to a data recording medium using only the allocated time slot. Access to For example, the port of channel 1 uses the time slot of slot number # 1, the port of channel 2 uses the time slot of slot number # 2,
Each port is assigned a time slot so that the port of channel 3 uses the time slot of slot number # 3 and the port of channel 4 uses the time slot of slot number # 4. Access timing is controlled. Then, by repeating this slot cycle with the passage of time,
Each port can access the data storage device in a time-sharing manner. As a result, the AV server system can perform simultaneous and parallel processing of data of four channels.

In the first time slot allocation method, each port cannot be accessed using a time slot other than the time slot to which each port is allocated. In the example described above, the time slot of slot numbers # 2, # 3, and # 4 is not allocated to the port of channel 1. Therefore, in the first time slot allocation method, when a command such as a data recording start command, a reproduction start command, or a high-speed reproduction start command is given from the user to the AV server system, the operation starts after the command is given. There was a possibility that a large delay might occur before starting.

For example, as shown in FIG. 5, at the time of slot number # 4 within a certain slot period, commands such as a recording start command, a reproduction start command, and a high-speed reproduction command of data input / output to / from the port of channel 2 are provided. Is given to the AV server system from a user or the like. In this case, in the first time slot allocation method, at the moment when this command is given, the AV server system cannot perform an operation such as recording start, and the slot number # 2 in the next slot cycle.
Until this slot arrives, it must wait for an operation for that instruction. In the worst case, a delay of one slot period occurs.

Next, a second time slot allocation method will be described with reference to FIG.

[0011] The second time slot allocation method is also:
Similarly to the first time slot allocation method, one slot period composed of the same number of time slots as the number of ports of the AV server system is determined. 4 ports
Therefore, one slot period composed of four time slots is determined. Similarly, each time slot constituting one slot period is assigned a slot number. Here, slot numbers # 1 to # 4 are assigned.

In the second time slot allocation method, for example, as in the first time slot allocation method, for example, the port of channel 1 uses the time slot of slot number # 1 and the port of channel 2 Within one slot period, the time slot of slot number # 2 is used, the port of channel 3 uses the time slot of slot number # 3, and the port of channel 4 uses the time slot of slot number # 4. Assigned.

Here, in the second time slot allocation method, time slots allocated to unused ports are released and allocated to other ports.

For example, as shown in FIG. 7, it is assumed that no data is input / output to / from the port of channel 1 so that the port is not used and the time slot of slot number # 1 is open. At this time, for example, at the time of slot number # 4 within a certain slot cycle, commands such as a recording start command, a reproduction start command, and a high-speed reproduction command of data input / output to / from the port of the channel 2 are issued from the user or the like to the AV server system. And given to In this case, according to the second time slot allocation method, the time slot of slot number # 1 that is supposed to be used by the port of channel 1 is opened, and thus the released slot number # 1 is used.
Can be assigned to the port of channel 2 in the next slot cycle.

[0015] Therefore, in the second time slot allocation method, the delay from when an instruction is given to the start of operation is shorter than in the first time slot allocation method, and the responsiveness of the system is reduced. Can be improved.

However, even in the second time slot allocation method, for example, as shown in FIG. 8, the time slot of slot number # 3 is not open, When the slot has been released, the operation delay is that the operation for the instruction is waited until the slot of the slot number # 2 of the next slot period arrives, as in the first time slot allocation method. There must be.

[0017]

As described above, the conventional A
In the V server system, the time slots are allocated as described above. For example, when the recording operation and the reproduction operation are started, or when the reproduction direction is reversed or the operation is switched to the high-speed reproduction operation, the reaction is performed. Was likely to be slow and the operability was poor.

The present invention has been proposed in view of such circumstances, and has as its object to provide a data input / output device and a data input / output method with improved operability.

[0019]

In order to solve the above problems, a data input / output device according to the present invention comprises a plurality of input / output devices for inputting / outputting data to be recorded on a recording medium or data reproduced from the recording medium. An output unit configured to record the data input to the plurality of input / output units on the recording medium and reproduce the data output from the plurality of input / output units from the recording medium; Management means for managing the timing at which the output means accesses the recording medium by allocating a time slot having a fixed time width to each input / output means, wherein the time width of the time slot is overwritten by 1. A time during which the output means can record and reproduce a data amount equal to or more than the data amount when data is input and output at a constant speed continuously for a predetermined period with respect to the recording medium. The input / output means of each of the plurality of input / output means, when it becomes possible to access the recording medium, makes a time slot use application to the management means, and the management means At least one time slot, which has the highest priority over other input / output means in the predetermined period and can access the recording medium, is set for each input / output means. The time slot is assigned to one input / output unit having a high priority by judging the priority of the input / output unit.

In the data input / output device according to the present invention, it is set that the management means is an input / output means which has the highest priority over other input / output means and can access the recording medium. Except when assigning a time slot to its highest-priority input / output means, the input / output means whose data input / output speed has changed are compared to the input / output means which inputs / outputs data at a constant speed. Assign a time slot with a higher priority.

In the data input / output device as described above, even when a certain input / output unit is recording or reproducing data input / output at a constant speed, this input / output unit is used with the highest priority. If there is an empty time slot before the possible time slot, the input / output means moves forward and uses the empty time slot. Therefore, the time slot that the input / output means can use most preferentially becomes empty, and the empty time slot can be used by other input / output means. Therefore, for example, when the variable speed reproduction is performed in another input / output means, there is a probability that an empty time slot exists before the time slot which can be used by the other input / output means with the highest priority is reached. Therefore, the time from when a command such as variable speed reproduction is issued to when an empty time slot is reached is short.

According to a data input / output method of the present invention, data input to a plurality of input / output interfaces is recorded on a recording medium, and data output from the plurality of input / output interfaces is reproduced from the recording medium. For this reason, the timing at which the plurality of input / output interfaces accesses the recording medium is managed by assigning a time slot having a fixed time width to each input / output interface, and data for inputting / outputting a plurality of data is controlled. An input / output method, wherein the time width of the time slot is a data amount equal to or greater than the data amount when one of the input / output interfaces continuously inputs and outputs data at a constant speed for a predetermined period. Is set to a time width in which recording and reproduction can be performed with respect to each other. In the system slot, at least one time slot, which has the highest priority than other input / output interfaces and can access the recording medium, is set for each input / output interface. When the input / output interface becomes accessible to the recording medium, a time slot use request is made, and for each time slot, the priority of the input / output interface for which use has been requested is determined. The time slot is allocated to one high input / output interface.

In the data input / output method according to the present invention, the time slot set as the input / output interface which has the highest priority over other input / output interfaces and can access the recording medium is assigned the highest priority. Except when assigning to a high I / O interface, the I / O interface whose data input / output speed has changed has a higher priority than the input / output interface that inputs / outputs data at a constant speed. Assign time slots.

In the data input / output method as described above, even when a certain input / output interface records or reproduces data input / output at a constant speed, the input / output means has the highest priority. If there is an empty time slot before the possible time slot, the input / output interface moves forward and uses the empty time slot. Therefore, the time slot that the input / output interface can use most preferentially becomes empty, and the empty time slot can be used by other input / output means. Therefore, for example, when the variable speed playback is performed in another input / output interface, there is a probability that an empty time slot exists before the time slot which can be used by the other input / output interface with the highest priority is reached. Therefore, the time from when a command such as variable speed reproduction is issued to when an empty time slot is reached is short.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, an AV server system to which the present invention is applied will be described in detail with reference to the drawings.

The present invention is applied to an AV server system 1 as shown in FIG. The AV server system 1 shown in FIG. 1 performs recording, reproduction, editing, and the like of AV (audio and / or video) data on four channels.
The recording, reproduction, editing, and the like can be performed in parallel with the channels at the same time.

The AV server system 1 includes a data storage section 2 for storing AV data, and an AV data section for accessing the data storage section 2 to record and reproduce AV data and to input / output AV data to / from the outside. I / O interface (hereinafter simply referred to as I / O port)
5, 6 and a system controller 7 for controlling the entire system.

The data storage unit 2 is a RAID (Redundant Arrays) in which a plurality of hard disk drives (HDDs) are arranged.
This is a so-called multi-channel type data storage device using the Inexpensive Disks method. The data storage unit 2 receives access from a plurality of input / output ports 3, 4, 5, and 6, and stores AV data input from each of the input / output ports 3, 4, 5, and 6.

The input / output ports 3, 4, 5, and 6 record AV data supplied from the outside in the data storage unit 2 and reproduce the AV data stored in the data storage unit 2. Send to outside. Each input / output port 3, 4, 5,
6 can independently input and output AV data. Therefore, the user of the AV server system 1 can independently perform operations such as reproduction, recording, and editing on the AV data input to and output from the input / output ports 3, 4, 5, and 6.

Each input / output port 3, 4, 5, 6
An internal memory for storing AV data is provided for adjusting the timing of accessing the data storage unit 2 and the timing of input / output of AV data to the outside. Each of the input / output ports 3, 4, 5, and 6 stores AV data continuously input from the outside at a predetermined input speed once in this internal memory, and thereafter, at a predetermined timing for each predetermined data amount.
The data is supplied intermittently to the data storage unit 2. Each of the input / output ports 3, 4, 5, and 6 stores the AV data intermittently reproduced at a predetermined timing from the data storage unit 2 at a predetermined timing for each predetermined data amount in this memory, and then outputs a predetermined output data. Output continuously to the outside at the speed.

Each input / output port is assigned a channel number. Here, the input / output port 3 is set as channel 1, the input / output port 4 is set as channel 2, the input / output port 5 is set as channel 3, and the input / output port is set as channel 3. Output port 6 is channel 4.

Each input / output port may have an encoding / decoding device such as an MPEG-2 encoder / decoder inside. For example, input / output with the outside is performed by baseband data, and a data storage unit is provided. 2 may be MPEG-compressed data.

The system controller 7 controls the timing of recording AV data from the input / output ports 3, 4, 5, and 6 to the data storage unit 2, and the timing from the data storage unit 2 to the input / output ports 3, 4, 5, and 6. To control the timing of reproducing the AV data. That is, the system controller 7
The timing at which each of the input / output ports 3, 4, 5, and 6 accesses the data storage unit 2 is controlled.

Specifically, the system controller 7
A fixed allocation time (hereinafter, referred to as a time slot) divided by time division is created, and one of the input / output ports 3, 4, 5, and 6 is allocated to this time slot. The input / output ports 3, 4, 5, and 6 are assigned to the data storage unit 2 at the timing when the allocated time slot arrives.
Can be accessed, and recording or reproduction of AV data can be performed.

The system controller 7 manages time slots by defining one slot cycle composed of the same number of time slots as the number of input / output ports for inputting / outputting AV data. Here, since the number of input / output ports is four, one slot cycle composed of four time slots is determined. Each time slot constituting one slot period is assigned a slot number.
Here, slot numbers # 1 to # 4 are assigned.

With respect to the time width of the time slot, a data amount equal to or larger than the data amount when data is continuously input and output at the normal speed during one slot period can be recorded and reproduced in the data storage unit 2. Set to time. For example,
In the AV server system 1 capable of inputting / outputting four channels of AV data, even when a time slot is assigned to one input / output port once every four times, input / output data is broken without interruption. Is set to such a time width that does not occur. As an example, in the AV server system 1, the time width of one time slot can be set to four frame times, and the one slot cycle can be set to 16 frame times. One input / output port intermittently accesses the data storage unit 2. However, since the internal memory stores more data than the data amount in one slot cycle (in the above-described example, AV data input / output to / from the outside is continuous without being intermittent. In addition, the time slot should be set to a time width that is not too large so that the capacity of the internal memory provided in each of the input / output ports 3, 4, 5, and 6 becomes as small as possible and the responsiveness of the system is improved. Good.

Next, the assignment of time slots in the AV server system 1 to which the present invention is applied will be described.

First, in the AV server system 1, a recording start command, a reproduction start command, a reproduction direction inversion command,
A command to change the reproduction speed is given, and according to these commands, each of the input / output ports 3, 4, 5, and 6 communicates with the external
Input / output of V data and recording / reproduction with the data storage device 2 are started.

Each of the input / output ports 3, 4, 5, and 6 is supplied with a reproduction start command when a recording start command is supplied and the recording preparation is completed, and is supplied with a reproduction direction inversion command when the reproduction preparation is completed. When the preparation for reverse playback is completed, or when the command for changing the playback speed is given and the preparation for high-speed playback or the like is completed, a time slot use application is sent to the system controller 7. That is, each of the input / output ports 3, 4, 5, and 6 makes a time slot use application to the system controller 7 when the data recording device 2 can be accessed.

Here, when the recording preparation for each of the input / output ports 3, 4, 5, and 6 is completed, for example, when recording AV data, one slot time (for example, 1
This is a time when AV data for 6 frame times) is stored and AV data for one slot time can be continuously recorded in the data storage unit 2. Also, the time when each input / output port is ready for reproduction means that, for example, during reproduction of AV data, one slot time (for example, 1
This is a time when a free space capable of storing AV data for six frame times) is secured, and AV data for one slot time can be continuously output to the outside.

The application for use of the time slot sent from each of the input / output ports 3, 4, 5, 6 to the system controller 7 is performed when AV data is input / output at a constant speed or data is input / output at a high speed. Regardless of the input / output speed of data, such as whether data is input or output, this is always performed when the preparation for recording or reproduction is completed.

Note that the normal speed is a data speed output from the input / output ports 3, 4, 5, and 6 when the AV data is reproduced at 1 × speed.

An application for using such a time slot is as follows.
The data is sent from each of the input / output ports 3, 4, 5, and 6 to the system controller 7 for each time slot.

The system controller 7 determines the priority of one or more input / output ports 3, 4, 5, and 6 for which the use of the time slot has been applied as described above, and preferentially assigns the time slot. One input / output port to be performed is determined, and a license is given to the determined input / output port.

Then, the input / output port to which the license is given records or reproduces AV data using the time slot. In addition, the input / output port to which the license has not been given requests the use of the next time slot to the system controller 7 again.

The system controller 7 determines the priority of the input / output port using the time slot for which use has been requested according to steps S1 to S7 shown in FIG. 2 as follows.

First, the system controller 7 sums up the application for use of the time slot transmitted from each of the input / output ports 3, 4, 5, and 6 (step S1).

Subsequently, it is determined whether or not there is a use application from an input / output port that can use the time slot with the highest priority based on the result of the aggregation (step S2).

Here, four time slots of slot numbers # 1 to # 4 are included in one slot period, but the system controller 7
One input / output port that can use the time slot with the highest priority is set. This system controller 7
For example, the input / output port 3 of channel 1 uses the time slot of slot number # 1 most preferentially, the input / output port 4 of channel 2 uses the time slot of slot number # 2 most preferentially, The input / output port 5 of channel 3 uses the time slot of slot number # 3 with the highest priority, and the input / output port 6 of channel 4 uses the slot number # 3.
4 time slots are determined to be used with the highest priority. The input / output port that can use the time slot with the highest priority is hereinafter referred to as the highest priority port. For example, in the above example, the highest priority port of the time slot of slot number # 1 is channel 1
Input / output port 3.

Subsequently, if there is an application for use of the time slot from the highest priority port, the system controller 7
The license of the time slot is given to the highest priority port, and the process of allocating the input / output port to the time slot ends (step S3). The top-priority port to which the license is granted can access the data storage unit 2 using the time slot and perform recording or reproduction.

Subsequently, if there is no application for use of the time slot from the highest priority port, reproduction of AV data, reversal of the input / output port or recording direction where recording was started, switching of the reproduction speed, and the like are performed. It is determined whether there is an application for use from an input / output port such as the input / output port whose input / output AV data whose speed has changed (step S3). That is, a command such as a recording start or a reproduction start is newly given from a user or the like, and it is determined whether or not there is an application for use of the time slot from an input / output port waiting for operation start. In addition, an input / output port in which the input / output AV data undergoes a speed change is hereinafter referred to as a speed change port.

Subsequently, if there is an application for use of the time slot from the speed change port, the system controller 7
Gives the license of the time slot to this speed change port, and terminates the input / output port assignment process for the time slot (step S4). The speed change port to which the license is given can access the data storage unit 2 using the time slot and perform recording or reproduction.

Subsequently, when there is no application for use of the time slot from the highest priority port and the speed changing port,
The system controller 7 determines whether or not there is a use request from the input / output port that is recording or reproducing at a constant speed where no change occurs in the speed of the input / output AV data (step S6). Note that this input / output A
An input / output port that records or reproduces data at a constant speed at which no speed change occurs in the V data is hereinafter referred to as a constant speed port.

Subsequently, if there is an application for use from the fixed speed port, the system controller 7 grants the use of the time slot to the fixed speed port, and terminates the input / output port allocation process for the time slot ( Step S7). The fixed-speed port to which the license has been granted can access the data storage unit 2 using the time slot and perform recording or reproduction.

Subsequently, when there is no application for use of the time slot from the highest priority port, the speed change port, and the constant speed port, the system controller 7 releases the time slot, that is, to any input / output port. The process ends without assigning the time slot (step S8).

The system controller 7 performs the processing of steps S1 to S7 for each time slot, and performs processing of allocating one input / output port to one time slot.

As described above, the system controller 7
When the use request of the time slot is made from the highest priority port, the time slot is always preferentially assigned to the highest priority port even if the use request is made simultaneously from other input / output ports. For example, if there is a use application from the input / output port 3 of the channel 1 to the time slot of the slot number # 1, the license is always given to the input / output port 3 of the channel 1. Similarly, the input / output port 4 of channel 2 for the time slot of slot number # 2, the input / output port 5 of channel 3 for the time slot of slot number # 3, and the input / output port 5 of slot number # 4. In this case, a license is always given to the input / output port 6 of the channel 4.

Therefore, each input / output port 3, 4, 5, 6
Can use a time slot at least once in one slot period in any situation, and no failure occurs in input / output of AV data.

The system controller 7 sets the input / output port as the highest priority port even if the input / output port is reproducing at a constant speed, if the preparation for recording or reproduction is completed. A free time slot existing before the current time slot is used.

For example, it is assumed that the input / output port 5 of the channel 3 set as the highest priority port in the time slot of the slot number # 3 is not used. In such a case, as shown in FIG.
However, if the application for use is made before the time slot of slot number # 3 arrives, the time slot of slot number # 3 can be used earlier.

When the device is used ahead of time, the time slot of slot number # 1 which arrives next is released.

Further, in such a case, as shown in FIG. 3, for example, at the time of the time slot of slot number # 4, a recording start command and a reproduction start command of data input / output to the input / output port 4 of the channel 2 are started. It is assumed that a command such as a command and a high-speed reproduction command is given to the AV server system 1 from a user or the like. In this case, since the time slot of the slot number # 1 in which the input / output port 3 of the channel 1 is set as the highest priority port is open, the time slot of the open slot number # 1 is changed to the next slot. It can be assigned to the input / output port of channel 2 periodically.

Therefore, in the second time slot allocation method, the delay from when an instruction is given to the start of operation is shorter than that in the first time slot allocation method, and the responsiveness of the system is reduced. Can be improved.

As described above, in the AV server system 1 according to the present invention, the input / output port for inputting / outputting AV data at a constant speed uses only the time slot set as the highest priority port to store data. Instead of accessing the unit 2, the data storage unit 2 is moved forward by using another time slot. So, for example,
The time from when each input / output port requests use of a time slot to when the input / output port that has actually requested the use can access the data storage unit 2 is short,
For example, the responsiveness at the start of the operation of the input / output port is good, for example, when a certain input / output port starts recording or reproducing data or when starting variable speed reproduction. Therefore, in the AV server system 1, the responsiveness at the time of editing is good, and the operability is improved without giving a stress to the operator.

[0065]

According to the data input / output device according to the present invention,
After each input / output means requests use of the time slot,
The time until the input / output means that actually requested the use can access the recording medium is short, for example, when a certain input / output means starts recording or reproducing data or starts variable-speed reproduction. The responsiveness at the start of the operation of the input / output means is good. Therefore, in the data input / output device, since the response at the time of editing is good, the operability is improved without giving a stress to the operator.

In the data input / output method according to the present invention, the time from when each input / output interface requests use of a time slot to when the input / output means which has actually requested the use can access the recording medium. The responsiveness at the start of the operation of the input / output means is good, for example, when a certain input / output interface starts recording or reproducing data or when starting variable speed reproduction. for that reason,
In this data input / output device, the responsiveness at the time of editing is good, so that operability is improved without stressing the operator.

[Brief description of the drawings]

FIG. 1 is a block diagram of an AV server system to which the present invention has been applied.

FIG. 2 is a flowchart showing processing contents of a system controller of the AV server system.

FIG. 3 is a time chart for explaining a time slot allocation method used in the AV server system.

FIG. 4 is a time chart for explaining a conventional time slot allocation method.

FIG. 5 is a time chart for explaining a delay caused by the conventional time slot assignment method.

FIG. 6 is a time chart for explaining another conventional time slot allocation method.

FIG. 7 is a time chart for explaining a delay caused by another conventional time slot allocation method.

FIG. 8 is a time chart for explaining a large delay caused by the other conventional time slot allocation method.

[Explanation of symbols]

1 AV server system, 2 data storage unit, 3-6
I / O port, 7 system controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H04N 5/262 H04N 5/91 L

Claims (4)

[Claims] A plurality of input / output means for inputting / outputting data to be recorded on a recording medium or data reproduced from the recording medium; and recording data input to the plurality of input / output means on the recording medium. In order to perform the data output from the plurality of input / output means from the recording medium, the timing at which the plurality of input / output means accesses the recording medium is defined by a time slot having a fixed time width. Management means for managing by assigning to the input / output means, wherein a time width of the time slot is equal to or larger than a data amount when one of the input / output means inputs and outputs data continuously at a constant speed for a predetermined period. Is set to a time width in which recording and reproduction can be performed on the recording medium, and each of the plurality of input / output units can access the recording medium. When the status becomes available, the management unit makes an application for using the time slot to the management unit, and the management unit has the highest priority over other input / output units in the predetermined period and gives the storage medium the highest priority. At least one time slot that can be accessed is set for each input / output means, and for each time slot, the priority of the input / output means for which use has been requested is determined, and one input / output means having a higher priority is used. A data input / output device, wherein the time slot is assigned to the data input / output device. 2. The management means according to claim 1, wherein said time slot which is set to be the input / output means having the highest priority and being able to access said recording medium has the highest priority than other input / output means. Except when assigning to output means, the priority of the input / output means whose data input / output speed has changed is made higher than that of the input / output means for inputting / outputting data at a constant speed, and the time slot is changed. 2. The data input / output device according to claim 1, wherein the data is assigned. 3. The plurality of input / output interfaces for recording data input to the plurality of input / output interfaces on a recording medium and reproducing data output from the plurality of input / output interfaces from the recording medium. A data input / output method for inputting / outputting a plurality of data by managing a timing at which an interface accesses the recording medium by allocating a time slot having a fixed time width to each input / output interface; The time width of the time slot is to record and reproduce a data amount greater than or equal to the data amount when one of the input / output interfaces continuously inputs and outputs data at a constant speed for a predetermined period. Each time slot within the above-mentioned predetermined period has another input / output At least one time slot, which has the highest priority than the interface and is capable of accessing the recording medium, is set for each input / output interface. When it becomes possible to access the I / O interface, a time slot use application is made. For each time slot, the priority of the input / output interface for which use has been applied is determined. A data input / output method, wherein the time slot is allocated. 4. When assigning a time slot, which is set to be an input / output interface having the highest priority and access to the recording medium to another input / output interface, to the input / output interface having the highest priority. In addition to the above, the I / O interface whose data input / output speed has changed has a higher priority than the input / output interface which inputs / outputs data at a constant speed, and time slots are assigned. 4. The data input / output method according to claim 3, wherein: