JPH11346237A - Information processing system, its method and provision medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the processing load in the case of interconnecting devices connecting to a bus. SOLUTION: An input plug number, a physical ID of a data output destination or output source, an output plug number and a data transfer rate between devices for data transmission/reception are preset to a device that manages bus connection in the case of bus reset according to sets of processing in the steps S1 through S6. Then the device the manages bus connection sends a parameter set to one device of the devices making a connection request. The device receiving the parameter sets a point-to-point connection to the other device according to the parameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing system and method, and a providing medium.
An information processing system and method for transmitting the parameter to a connected device and receiving the transmitted parameter, based on the parameter, for exchanging data by securing a channel and a band, and Regarding the providing medium.

[0002]

2. Description of the Related Art In a network including a plurality of devices, when data is exchanged between devices existing on the network, it is necessary to designate a device for transmitting data and a device for receiving data. . This designation corresponds to a device (node) I set on this network.
D.

For example, a predetermined device A causes a user to display the names and icons of the devices connected to the network on a monitor to which the user is connected. Device B that sends
And a device C that receives the data, and it is assumed that the transmission and reception of data performed between the specified devices B and C is controlled, the device A to be controlled is notified to the user on the monitor. In order to display device icons and the like on the network, the attributes of devices existing on the network and data necessary for control must be obtained in advance from the network.

When the data transfer rate of a network changes depending on the performance of a device that relays data, data for determining the transfer speed of data communication between target devices is obtained from the network.

[0005] Explaining an example of IEEE1394 as a network, when transmitting video data with a digital camcorder or the like, the connection management specified in IEC1883 is required.
Data transmission is performed using Broadcast Connection communication of entProtocol. In this method, the IEEE1394 is used without specifying the device ID of the device to which data is transmitted.
The channel of the isochronous communication is fixed at a constant value, and the receiver and the transmitter transmit and receive data in accordance with the channel, thereby enabling data transmission and reception.

[0006]

However, as described above, a process for acquiring data of a device on a network is performed by a high-performance CPU (Centr
al Processing Unit) and RAM (Random Access Memor)
This is possible processing for devices equipped with y).
High-performance CPU and R, such as V (Audio Visual) equipment
There has been a problem that it is difficult to perform the same processing on a device without the AM.

When data is transmitted and received in accordance with IEC1883 in the above-described network constituted by IEEE1394, the data transmitting side transmits data regardless of the presence or absence of the data receiving side. Therefore, when there is no receiving device, the bandwidth of the bus is wasted. Furthermore, since the data transfer rate is set at the lowest transfer rate regardless of the capabilities of the transmitter and the receiver, even if data is transmitted and received between devices having high processing capabilities, There was a problem that it could not be carried out effectively.

In IEC1883, a point-to-point controller that specifies a communication partner and controls data transmission / reception (input / output).
However, when data is transmitted and received using this, it is necessary to acquire data such as the configuration of devices on the network and transfer speed. For example, there is a problem that the processing becomes difficult.

The present invention has been made in view of such a situation, and an apparatus for performing connection management sets parameters necessary for making a connection, transmits the parameters to a connected apparatus, and transmits the parameters. The device that has received the parameters transmits and receives data by securing channels and bands based on the parameters.

[0010]

According to a first aspect of the present invention, in the information processing system, the first information processing apparatus transmits a parameter necessary for connecting the second information processing apparatus to another information processing apparatus. Setting means for setting, and transmitting means for transmitting the parameter set by the setting means to the second information processing apparatus, wherein the second information processing apparatus receives the parameter transmitted by the transmitting means And a securing means for securing a band and a channel with another information processing apparatus based on the parameters received by the receiving means.

According to a fifth aspect of the present invention, in the information processing method of the first information processing apparatus, a parameter required for connecting the second information processing apparatus to another information processing apparatus is set. A setting step, and a transmitting step of transmitting the parameter set in the setting step to the second information processing apparatus, wherein the information processing method of the second information processing apparatus includes:
A receiving step of receiving the parameters transmitted in the transmitting step; and a securing step of securing a band and a channel with another information processing apparatus based on the parameters received in the receiving step. .

According to a sixth aspect of the present invention, there is provided a medium for providing a computer program to a physical system, for connecting a second information processing apparatus to another information processing apparatus to a first information processing apparatus. And a transmission step of transmitting the parameter set in the setting step to the second information processing apparatus, wherein the parameter transmitted in the transmission step is transmitted to the second information processing apparatus. Providing a computer-readable program for executing a process including a receiving step of receiving the information and a securing step of securing a band and a channel with another information processing apparatus based on the parameters received in the receiving step. It is characterized by doing.

[0013] In the information processing system according to the first aspect, the information processing method according to the fifth aspect, and the providing medium according to the sixth aspect, the first information processing apparatus includes a second information processing apparatus and a second information processing apparatus. A parameter necessary for connecting to another information processing device is transmitted to the second information processing device, and the second information processing device communicates with the other information processing device based on the received parameter. Bandwidth and channels are reserved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

[0015] The information processing system according to claim 1 is
The first information processing apparatus is a setting unit that sets parameters necessary for connecting the second information processing apparatus and another information processing apparatus (for example, steps S101 to S101 in FIG. 17).
104) and the parameters set by the setting means,
Transmission means for transmitting to the second information processing apparatus (for example,
1394 interface 17), and the second information processing device receives the parameter transmitted by the transmitting unit (for example, the 1394 interface 34 in FIG. 3).
And, based on the parameters received by the receiving means,
Securing means for securing a band and a channel with another information processing apparatus (for example, steps S112 to S1 in FIG. 28)
14).

According to a fourth aspect of the present invention, in the information processing system, the first information processing apparatus includes a display control means for performing control for displaying a connectable information processing apparatus among the plurality of information processing apparatuses. Step S83), and a selection unit (for example, step S88 in FIG. 15) for selecting a connected device from the screen displayed by the display control unit, and the setting unit is configured to execute a process for the information processing apparatus selected by the selection unit. It is characterized by setting parameters.

FIG. 1 is a diagram showing a configuration of an information processing system according to an embodiment of the present invention. The CS tuner 1 is connected to a monitor 2 and a VTR (video cassette recorder) 3, and the VTR 3 is connected to another VTR 4. The CS tuners 1, VTR 3 and VTR 4 are connected by a 1394 bus 5. The CS tuner 1, VTR 3, and VTR 4 are connected to the monitor 2 by a cable (not shown). The information processing device of the present invention
It is not necessary to incorporate it into the CS tuner 1, and it may be a device that exists alone.

FIG. 2 is a block diagram showing the internal configuration of the CS tuner 1. The signal received by the antenna 20 is
It is input to the CS tuner main unit 11. The CS tuner main unit 11 performs processing such as demodulation and descrambling of the input signal, and adds the processed data to an adder 18.
To the NTSC encoder 16 via the. Or C
The S tuner main unit 11 outputs the processed signal to the 1394 interface 17.

The command transmitted by the user by operating the remote controller 21 is received by the infrared light receiving section 15 of the CS tuner 1. Based on the received command, CP
The U 12 controls the CS tuner main unit 11 and the 1394 interface 17. Further, the CPU 12 executes a GUI (Graph
ical User Interface) controls the engine 14, creates a menu screen or the like as necessary, outputs it to the adder 18,
The video data output from the CS tuner main unit 11 is output to the NTSC encoder 16.

The video data input to the NTSC encoder 16 is converted into an NTSC signal and output to the monitor 2. The CPU 12 records the data in the RAM 13 as necessary,
Read the stored data as needed.

FIG. 3 is a block diagram showing the internal configuration of the VTR 3 or VTR 4. Here, a description will be given as VTR3. The VTR control unit 31 controls a video recording / reproducing operation according to a command from the CPU 33. The VTR control unit 31 inputs data transmitted from another device via the 1394 interface 34. Conversely, the VTR control unit 31 outputs the video data to another device via the 1394 interface 34. Further, the VTR control unit 31 outputs the video data as a result of the control to the monitor 2 via the NTSC encoder 36.

The CPU 33 allows the user to operate the operation panel unit 3.
8, or controls the VTR control unit 31 based on data instructed by operating the remote controller 40. The data instructed by the remote controller 40 is received by the infrared light receiving unit 37 and transmitted from the infrared light receiving unit 37 to the CPU 33.

Further, the CPU 33 stores data in the RAM 32 and reads out the stored data as required. The CPU 33 causes the display unit 35 to display the remaining amount of a video tape (not shown), a frame counter, and the like.

CS tuner 1 having such an internal structure
Data transmission and reception between devices in a network to which the VTRs 3 and 4 are connected will be described.

First, referring to the flowchart of FIG. 4, when a connected device is removed or newly connected from the already configured network, that is, the device is connected to the bus. A description will be given of a process for newly investigating the device configuration when the configuration of the device has changed. The processing of this flowchart is performed by the CS tuner 1 that manages the devices on the network.

When the configuration of a device on the network constituted by the 1394 bus 5 changes, a bus reset occurs.
When a bus reset signal is input to the 1394 interface 17 of the CS tuner 1 in step S1, the CP
U12 is notified of this. In step S2, a Self ID packet transmitted from each device to the 1394 bus 5 is received. This Self ID packet is a packet having a format as shown in FIG.

In the Self ID process, any one to four Self ID packets are output from the physical layer of each device (node). Self shown in FIG.
If the ID packet is one, or S is output first
FIG. 5B shows an example of an elf ID packet.
It is an example of the Self ID packet output at the time of the first. Self ID
The first 32 bits of the packet are valid data, and the remaining 32 bits are used for error detection.

FIG. 6 is a diagram for explaining the components of the Self ID packet. The content described in the cell below the cell in which the name is described in the top row corresponds to the name of the component of the Self ID packet in FIG. A cell placed at the position where the rightward extension area of the content described in the cell below the cell described as the field of the top row and the downward extension area described in the top row content Is the Self
It shows the contents of the components of the ID packet. The node that has received the Self ID packet has 10
The information stored in the bit L field L is read and Self
The operation state of the link layer of the node that has output the ID packet can be known. Other devices that know that the link layer of a given device is operating, with respect to the given device,
Communication can be performed via the link layer.

The CPU 12 analyzes the Self ID packet having such a format to determine the total number of devices on the bus, whether or not the link layer of each device is operating, the data signal transfer speed of each device, and Obtain information such as the bus tree structure.

In step S3, the CS tuner 1
The CPU 12 analyzes the tree structure of the bus from the received Self ID packet. The analysis of this tree structure is shown below.
Utilizes three features of a network connected by a 94 bus. First, there is only one parent node for one node (device). Second, a child node of a given node is smaller than its node number, and its parent node is larger than its node number. Third, the root node has no parent node.

Using such features, the tree structure can be analyzed if the node number (range of numbers from 0 to 62) and the number of child nodes (range from 0 to 27) of a predetermined node are known. It is possible to

After the analysis of the tree structure of the bus is completed in step S3, the data transfer speed between devices connected on the network is analyzed in step S4. In step S5, the node unique
The ID is read. In step S6, the plug number of each device is checked. In each process, the obtained data is stored in the RAM 13.

The analysis of the tree structure of the bus in step S3, the analysis of the data transfer speed in step S4, and the process of reading the node unique ID in step S5 will be described below.

When analyzing the tree structure of the bus, the CPU 12 transmits this packet from “sp” included in the Self ID packet # 0 (first packet) having the format shown in FIG. The data of the data transfer speed of the node (device) obtained is obtained. Then, “p0, p1, p2” of Self ID packet # 0 and “pa, pb, pc, pd, pe, p” of Self ID packets # 1 to # 3
The state of the port is checked from "f, pg, ph", and the number of channels is counted.

When such data is obtained, the total number of nodes (nNode) and the number of leaf nodes (LNode) at that time are counted. Then, the tree structure is analyzed from the obtained data. This analysis will be described with reference to the flowchart of FIG.

Here, "p" indicates a node ID that is a candidate for a parent node, and "c" indicates a node ID that is a candidate for a child node. “Node” indicates an array of tree nodes, and a subscript indicates a node ID. The range of this subscript is 0 to (nNode-1). “NNode” indicates the total number of nodes existing on the bus at that time. "N Chil
"d" indicates the number of child nodes of the node as a parameter of the tree node. "ParentID" indicates the node ID of the parent node of the node as a parameter of the tree node. Indicates the number of child nodes. "
“Push” and “pop” indicate stack operation functions for storing node IDs.

The CPU 12 reads the information as shown in FIG. 8 from the above-described Self ID packet and stores it in the RAM 13 in order to analyze the tree structure.
The processing of the flowchart shown in FIG. 7 is started.

In step S1, a value p of a node ID which is a candidate for a parent node is set to 0 which is an initial value. Further, the value p of the node ID set to 0 is pushed (PUSH) onto the stack. In step S2, the node ID
It is determined whether or not p is smaller than the total number of nodes nNode. If it is determined that p is smaller, the process proceeds to step S3. In step S3, the value of the counter indicating the number of undetermined child nodes is set as the number of child nodes (nChild) of the node whose node ID is p.

In step S4, it is determined whether the value of the counter set in step S3 or the value of the counter set in step S7 described later is 0. When it is determined that the value of the counter is not 0, in other words, when the node having the node ID of p has a child node, the process proceeds to step S5. In step S5, the node ID is popped (POP) from the stack, and the value of the popped node ID is set as a child node candidate node.
Set as IDc. Then, for the set c,
In step S6, the parent node ID of the node whose node ID is c is set as the value p of the candidate node ID of the parent node.

Then, in step S7, a value obtained by subtracting 1 from the counter value is set as a new counter value. After the setting, the process returns to step S4, and the subsequent processes are repeated.

In step S4, the value of the counter becomes 0
If it is determined that p is the node ID, p is pushed to the stack as a node ID. Then, in step S9, the value of p is incremented by 1, and the processing in step S2 and subsequent steps is repeated for a new p.

In step S2, the value of p is nNod
If it is determined that the value is larger than the value of e, step S10
And the stack is emptied. Then, the process of this flowchart, that is, the process of analyzing the tree structure is ended.

Such a process will be described with reference to an example in which data stored in the ROM 13 as shown in FIG. 8 is used. In this case, since the node ID is set from 0 to 5, the total number of nodes existing on the bus nNo
de is 6.

First, in step S1, the value p of the node ID as a parent node candidate is set to 0, so that the process proceeds from step S2 to step S3. It can be seen from FIG. 8 that the child node (nChild) of the node whose node ID is 0 is 0. Therefore, the process proceeds from step S4 to step S8. Then, in step S8, 0 is pushed on the stack, and in step S9, the value of p is updated to 1.

When the node IDs are 1 and 2, the process is the same as that described above, so that the description thereof will be omitted, and the description will be started from the case where the value of p is updated to 3 in step S9. If the node ID is 3, step S2 to step S
Proceed to 3. Then, in step S3, the number 2 of the child nodes whose node ID is 3 is set as the value of the counter. Then, the process proceeds from step S4 to step S5.

In step S5, the node ID is popped from the stack. In this case, the popped node ID is 2. Then, in step S6, ID3 of the parent node of node ID2 is set as the value of p.

In step S7, the value of the counter is 2
Is decremented by 1 to 1 and the processing from step S4 is repeated. In this case, since the value of the counter is 1, the process proceeds to step S5. In step S5, the node ID is popped from the stack. In this case, the popped value is 1. Node ID is 1
The parent node ID of the node is 3. Then, in step S7, the value of the counter is decremented by one and becomes zero. Therefore, the process returns to step S4, and then returns to step S4.
Proceed to 8.

In step S8, the value of p as the node ID, in this case 3, is pushed onto the stack. Then, in step S8, the value 3 of p is incremented by 1 and is set to 4, and the processing after step S2 is repeated.

The processing described above is also performed for the node IDs 4 and 5. Then, in step S9, p
Is incremented by 1 and when the value becomes 6, it is determined by the processing in step S2 that it is not smaller than the value 6 of nNode, the process proceeds to step S10, and the stack is emptied.

The tree structure analyzed in this way is as shown in FIG. That is, node ID5 is set as a parent node, and node ID0 and node ID4 are set as child nodes. The node ID4 is set as a parent node, and the node ID3 is set as a child node. Further, the node with node ID 3 is a parent node, and node IDs 1 and 2 are hanging as child nodes.

Next, by using the analyzed tree structure, a predetermined 2
The process of calculating the number of hops between two nodes will be described with reference to the flowchart in FIG. Where "m" and "
"n" indicates the node ID of a predetermined node, and "tm"
"p" indicates a temporary variable for exchange between two nodes, "top" indicates a node ID of a vertex when searching from the node m toward the root, and "node" indicates a node ID. Indicates the node ID when searching from n to the root, and "hop" indicates a hop number counter.

In step S21, two node IDs
It is determined whether or not the values m and n have a relationship of m> n. If it is determined that m is larger than n, the process proceeds to step S2, where m and n are exchanged. That is, tmp =
Let m, m = n, n = tmp. Then, step S23
Proceed to.

On the other hand, if it is determined in step S21 that the relation of m> n is not satisfied, the process proceeds to step S23.
In step S23, hop is set to -1. This is set as −1 as an initial value in order to make the number of hops with itself zero. Then, in step S24, top representing the node ID of the vertex at the time of searching from the node having the node ID value m toward the root is set to m.

In step S25, it is determined whether or not top is smaller than n. If it is determined that top is smaller, the process proceeds to step S26, where the value of hop is incremented by one. Then, in step S27, the node ID is
Let the ID of the parent node of p (ParentID) be the new value of top,
Step S25 and subsequent steps are repeated.

If it is determined in step S25 that the value of top is larger than n, the process proceeds to step S28.
In step S28, the value of the node is set to n. Then, in step S29, it is determined whether the value of the set node is equal to or less than top. If it is determined that the node is equal to or smaller than top, the process proceeds to step S30. In step S30, the value of the hop is incremented by one.

In step S31, if the node ID is node
Is set as the value of the new node, the process returns to step S29, and the subsequent processes are repeated.
If it is determined in step S29 that the value of the node is not smaller than the value of top, the process of this flowchart (the process of obtaining the number of hops between two predetermined nodes)
Is terminated.

Here, in the network having the tree structure shown in FIG. 9, a case where the number of hops between nodes whose node IDs are 1 and 4 is obtained will be described as an example, and the processing of the flowchart of FIG. 10 will be described. I do. Here, m = 1, n
= 4. With such settings, the process proceeds from step S21 to step S23. And step S
At 23, the value of hop is set to -1.

In step S24, top = m = 1 is set. Therefore, from step S25, step S25
Proceeding to 26, the value of hop is incremented by 1,
Set to 0. In step S27, the node ID is
The parent node ID of the top node is set to the value of top. In this case, the ID of the parent node whose node ID is 0,
5 is set as the value of top.

In step S25, it is determined whether or not the value of top set in step S27 is smaller than n. In this case, since n is 4, it is determined that the value is not small. Proceed to S28.

In step S28, the value of the node is n,
That is, it is set to 4. Then, in step S29, it is determined whether or not the value of node is equal to or less than the value of top. In this case, since node = 4 and top = 5, the process proceeds to step S30. In step S30, the value of hop is incremented by one and set to one.

In step S31, if the node ID is node
Is set as a new node. In this case, the parent node ID having a node ID of 4 and the parent node ID of 5 are set as new node values. And the set value 5
Is subjected to the process of step S29. In this case, since the value of the node is 5 and the value of the top is also 5, it is determined that the values are the same, the process proceeds to step S30, and the value of the hop is incremented by 1 to 2.

In step S31, the parent node ID, NONE (FIG. 8) of the node whose node ID is 5, is newly set.
Set as the value of node. Then, in step S29, the value of node is compared with the value of top.
Since the value of e is NONE, it cannot be compared. In such a case, since the definition cannot be made, the processing of this flowchart is ended as the avoidance processing. Therefore, the node
The number of hops between ID1 and node ID4 is 2 set in step S30.

Next, how to determine the data transfer speed between nodes will be described with reference to the flowcharts of FIGS. Here, “S1” and “S2” are
Indicates the data transfer speed, and “LSpeed” indicates S1 and S2
Indicates the smaller of

In step S41, the value m of the node ID
Or the value n is the total number of nodes existing on the bus nNod
It is determined whether it is greater than e. Since the node ID does not become larger than the total number of nodes existing on the bus, nNode, when such a case occurs, the process proceeds to step S42, and undefined (Undefined) is performed.
return it.

In step S41, node IDs m and n
Is not larger than the total number nNode of the nodes existing on the bus, or in step S42.
When the processing of is completed, the process proceeds to step S43. In step S43, it is determined whether the node ID m or n is 63. Since the node ID is 62 at the maximum, if the node ID m or n is 63, the process proceeds to step S44, and returns undefined.

In step S43, node IDs m and n
However, when it is determined that both are not 63, or when the process of step S44 is terminated, step S4
Go to 5. In step S45, node IDs m and n
Are both 62. 62 together
If it is determined that the answer is NO, the process proceeds to step S46, and undefined is returned. The process of step S46 is terminated, or in step S45, the node
If it is determined that both IDs m and n are not 62, the process proceeds to step S47.

In step S47, the value m of the node ID
Is greater than or equal to the node ID value n.
If it is determined that m is larger than n, step S
Proceeding to 48, m and n are interchanged. That is, tmp
= M, m = n, n = tmp. This step S48
Is completed, or when it is determined in step S47 that the value m of the node ID is smaller than the value n of the node ID, the process proceeds to step S49.

In step S49, S1 = S40
0, S2 = S400. In a network configured using the 1394 bus, the data transfer speed is set to S.
Three transfer speeds of 100, 1200 and S400 are prepared. This speed differs depending on the node, and is set according to the capability of the node.

In step S50, it is determined whether the transfer speed of node IDn is S100. Node ID n
Is determined to be S100, the process proceeds to step S51, and S100 is returned. Step S
51 is completed, or Step S50
When it is determined that the transfer speed of the node IDn is not S100, the process proceeds to step S52.

In step S52, the node ID of the vertex
Is set as the node ID value m. And this t
In step S53, it is determined whether op is smaller than node IDn. If it is determined that top is smaller than n, the process proceeds to step S54. In step S54, it is determined whether the transfer speed of the node with the node IDtop is S100. Then, the transfer speed of the node with the node IDtop is S100
If it is determined that the value is
00 is returned.

When the processing in step S55 is completed, or when it is determined in step S54 that the transfer speed of the node with the node IDtop is not S100,
Proceed to step S56. In step S56, it is determined whether the transfer speed of the node IDtop is equal to or less than S1. If it is determined that the transfer speed of the node with the node IDtop is equal to or lower than S1, the process proceeds to step S57, and the transfer speed of the node with the node IDtop is set to S1.

On the other hand, in step S56, the node ID
If it is determined that the transfer speed of the top node is not lower than S1, or if the process of step S57 is completed, the process proceeds to step S58. In step S58, the node ID of the parent node of the node ID top is set as a new value of top. When the process in step S58 is completed, the process returns to step S53, and the subsequent processes are repeated.

If it is determined in step S53 that top is not more than n, the flow advances to step S59. In step S59, node, which is the node ID when searching from the node ID n toward the root, is set to n. Then, the process proceeds to step S60, and it is determined whether or not the node is equal to or smaller than top. If it is determined that the node is equal to or smaller than top, the process proceeds to step S61.

At step S61, the node ID is node
It is determined whether or not the transfer speed of the node is S100. When it is determined that the transfer speed of the node IDn is S100, the process proceeds to step S62, and S100 is returned. If the process in step S62 is completed, or if it is determined in step S61 that the transfer speed of the node IDn is not S100, the process proceeds to step S63.
Proceed to.

In step S63, if the node ID is node
It is determined whether the transfer speed of the node is less than or equal to S2. If it is determined that the transfer speed of the node whose node ID is "node" is equal to or less than S2, the process proceeds to step S64.
To the transfer speed of the node whose node ID is node
Set to.

On the other hand, in step S63, the node ID
If it is determined that the transfer speed of the node where is the node is not lower than S2, or if the process of step S64 is completed, the process proceeds to step S65. In step S65, the node ID of the parent node whose node ID is node is
Set as a new node value. When the process in step S65 is completed, the process returns to step S60, and the subsequent processes are repeated.

If it is determined in step S60 that the node is not equal to or smaller than top, the flow advances to step S66. In step S66, in the above-described processing, the determined S1 and S2 are compared, and when it is determined that S1 is smaller than S2, in step S67, when it is determined that S1 is larger than S2, The process proceeds to step S68. In steps S67 and S68, the transfer speed determined to be low in step S66 is set as LSpeed.

The above-described processing for determining the data transfer speed between the two devices will be described by taking a node ID 2 and a node ID 4 as examples of two devices in the network having the tree structure shown in FIG. Here, m =
2, n = 4. Therefore, the process proceeds from step S41 to step S43, and then to step S45, and further proceeds to step S47.

In step S47, it is determined whether or not m> n. In this case, m = 2,
Since n = 4, it is determined that the relationship is not m> n, and the process proceeds to step S49. In step S49, S1 = S
2 = S400 is set. Then, step SS50
, The speed of the node whose node ID is n is S1
It is determined whether it is 00 or not. In this case,
Since the speed of the node 4 is S200, step S5
Proceed to 2.

In step S52, the value of top is m,
That is, 2 is set. In step S53, to
It is determined whether or not p <n. In this case, since top = 2 and n = 4, it is determined that top <n, and the process proceeds to step S54. In step S54, the speed of the node whose node ID is top is S100
In this case, since the speed of the node ID 2 is S200, the step S
Proceed to 56.

In step S56, the node ID is top
, Ie, the speed of the node whose node ID is 2, and whether or not S200 is equal to or less than S1 = S400. As a result, the process proceeds to step S57. In step S57, the node ID is set to top speed, and S200 is set as S1. Then, the process proceeds to a step S58, wherein the ID of the parent node of the node top is set to the new t.
Set as the value of op. That is, the value of the new top is 3.

For a new top value of 3, step S5
The processes after 3 are repeated. In this case, since the value of n is 4, the process proceeds from step S53 to step S54. Since the speed of node ID 3 is S100, step S5
The process proceeds from S4 to step S55, and S100 is returned. Then, the process proceeds to step S56, and it is determined whether or not the speed of the node having the node ID of 3 and S100 is smaller than S1. In this case, since S1 is S200 set in step S57, the process proceeds to step S57 by the process of step S56.

In step S57, the speed with the node ID of 3 and S100 are set as new S1.
Then, in step S58, 4 which is the parent node ID of the node having the node ID of 3 is set as a new top value. For this new top value of 4, step S5
The processes of 3 and below are repeated.

In step S53, top = 4, n =
4, it is determined that top <n is not satisfied, and step S5
Proceed to 9. In step S59, the value of the node is n,
That is, it is set to 4. The determination at step S60 is that node = 4 and top = 4 in this case, so that node <= t
It is determined that the relationship is op, and the process proceeds to step S61. In step S61, it is determined whether or not the speed of the node whose node ID is node is S100. In this case, node = 4 and the speed of the node whose node ID is 4 is S200. If not, the process proceeds to step S63.

In step S63, it is determined whether the speed of the node having the node ID of 4 and S200 are smaller than S2. In this case, since S2 is S400 set in step S49, it is determined that S2 is smaller than S2, and the process proceeds to step S64. Step S64
, The speed of S2 is set to the speed S200 of the node having the node ID of 4. Then, step S65
Then, the parent node ID of the node is set to the new node value. In this case, the parent node ID of the node ID of 4 and the parent node ID of 5 are set as the new node values.

The processing from step S60 is repeated for the node for which a new value is set. In this case, node =
5, since top = 4, it is determined that there is no relation of node <= n, and the process proceeds to step S66. In step S66, the magnitude relationship between S1 and S2 is determined. In this case, S
1 is S100 set in step S57, and S2
Is S200 set in step S64. Therefore, in step S66, it is determined that S1 is smaller than S2 (S1 <S2), and the process proceeds to step S67.

In step S67, LSpeed is set to S10.
Set to 0. In this way, the data transfer speed between the node with the node ID of 2 and the node with the node ID of 4 is set.

Next, the configuration (Configur
ation) Reading of the node unique ID existing in the ROM will be described. The node unique ID has a format as shown in FIG. 13. In this format, “node Vendor ID” composed of 24 bits, “chip id hi” composed of 8 bits, and 32 bits are used. By the “chip id lo” configured, the node (equipment)
It shows data such as vendors and models.

The CPU 12 of the CS tuner 1 reads such a node unique ID according to the flowchart of FIG. First, in step S71, the node number N is set to 0. In step S2, the node number N set in step S71 or the node having the node number N set in step S74 described below
It is determined whether the field L (FIG. 5) of the Self ID packet is 1 or not. Field L of SelfID packet is 1
Means that the link layer is operating. When the link layer is operating, it is possible to communicate with the node via the link layer.

If it is determined in step S72 that the field L of the Self ID packet is 1, the flow advances to step S73. In step S73, the node unique ID of the node for which the field L of the Self ID packet is determined to be 1 is read from the configuration ROM. When reading is completed, or in step S
If it is determined at 72 that the field L of the Self ID packet is not 1, the process proceeds to step S74, and the node number N is incremented by 1.

In step S75, it is determined whether or not the node number N is equal to the total number of nodes. If it is determined that the number is not the same as the total number of nodes, the process returns to step S72, and the subsequent processing is repeated. On the other hand, if it is determined in step S75 that the node number N is equal to the total number of nodes, in other words, if it is determined that the processing of this flowchart has been performed for all nodes, the processing of this flowchart is performed. Is terminated. The data of the node unique ID thus read is stored in the RAM 13
Is stored.

Next, when the user is connected to the bus 2
The processing of the CS tuner 1 when one device is selected and data is transmitted and received between the selected devices will be described with reference to the flowchart in FIG. First, in step S81, when connecting a device, the user performs a predetermined operation for displaying a screen displayed on the monitor 2. In response to the operation, in step S82, the CS tuner 1 first determines the name of the device connected to the bus and the name of the manufacturer from the node unique ID. This determination is made based on the data that has already been read and stored in the RAM 13 based on the flowchart described with reference to FIG.

Based on the determination in step S82,
In step S83, the CPU 12 of the CS tuner 1 controls the GUI engine 14 to display a screen as shown in FIG.

The display screen shown in FIG. 16 is a screen created based on the configuration example shown in FIG. The side that sends data (Output) is vertical, and the side that receives data (Inpu
t) is displayed next to each. Then, when the device displayed vertically and the device displayed horizontally overlap, the connection selection buttons 53a to 53f (hereinafter, when there is no need to distinguish each of the connection selection buttons 53a to 53f, simply Connection selection button 53) is displayed. The connection selection button 53 is displayed only between the connectable devices.
In the tuner, Input is not displayed in the place called CS tuner.

The user operates the cursor 51 to select the connection selection button 53 displayed between the devices to be connected. If the selection is satisfactory, the “select” of the command button 52 is operated by the cursor 51 similarly. This terminates the selection of the connection between the devices. When the selection is made again, "return" of the command button 52 is operated.

In step S84, a cursor movement process is performed in response to a user operation. On the other hand, in step S85, it is determined whether the connection selection button 53 or the command button 52 has been operated. Step S8 until one of the buttons is operated.
4 and step S85 are repeated. If it is determined in step S85 that any one of the buttons has been operated, the process proceeds to step S86.

In step S86, it is determined whether or not the operated button is the "return" button of the command button 52. If it is determined that the "return" button has been operated, the process proceeds to step S87, and after the predetermined process has been performed, the process of this flowchart ends.

On the other hand, if it is determined in step S86 that the operated button is not the "return" button of the command button 52, the flow advances to step S88. In step S88, the color of the operated button is inverted. Of course, instead of inverting the color, a process of using another color or blinking may be used. In the display example of FIG. 16, the connection selection buttons 53a and 53d are selected, and the other connection selection buttons b, c, e, and f are displayed in inverted colors.

In step S88, when the selected button, in this case, the button in the connection selection button 53, is displayed with its color inverted, the process proceeds to step S89. In step S89, data on the input device and output device of the selected button is stored in the RAM 13. For example, in the display example of FIG.
Since 3d is selected, the RAM 13 first stores the CS tuner 1 as the output device and the VTR 3 as the input device for the first relationship, and the VTR 3 as the output device and the VTR 4 as the output device for the second relationship. Are stored together with the relationship between the two input devices and the output device.

If the processing in step S89 is completed, the flow advances to step S90, where the "" of the command button 52
It is determined whether or not "SET" has been operated. Until the "SET" is operated, the process returns to step S84, and the subsequent processing is repeated, and in step S90, "SET" of the command button 52 is operated. If it is determined that the connection has been made, the process of this flowchart (the process of setting the connection between devices) is terminated.

In order to actually transmit and receive data between devices to which the connection has been set in this way, C
The processing performed by the S tuner 1 will be described with reference to the flowchart in FIG. First, connection processing for the setting connection button 53a is performed. In step S101, Inpu
t Plug No is set. This setting is made using the plug number of each device, which was checked in step S6 in FIG. That is, among the VTR3 plug numbers,
A number that can be used as a plug is set.

In step S102, the physical ID of the data output source node is set. In this case, C
This is the physical ID of the S tuner 1. Then, in step S103, the setting of Output Plug No is performed.
In this case, it is the plug number for the output of the CS tuner 1.

In step S104, the data transfer speed is set. This data transfer speed is
In the processing described with reference to the flowcharts of FIGS. 11 and 12, since it has already been determined and stored in the RAM 13,
Use the stored data. In this case, it is the data transfer speed between the CS tuner 1 and the VTR 3.

In step S105, it is determined whether there is a next pair (input device and output device). In this case, since there is a pair of VTR3 and VTR4 selected by the connection selection button 53d, the process returns to step S101, and the subsequent processing is repeated.

In step S101, Input Plug N
As o, the plug number of the VTR 4 is set. In step S102, the Physi of VTR4 that is the data output destination
calID is set. When the connection between the CS tuner 1 and the VTR 3 is set, the physical ID of the CS tuner 1, which is the data output source, is set. As described above, whether the physical ID of the data output destination or the physical ID of the data output source is set differs depending on the connected devices, and the details will be described later.

At step S103, Output Plug
As No, a plug number for output of the VTR 3 is set. In step S104, the data transfer speed between VTR3 and VTR4 is set. Then, in step S105, it is determined whether or not there is a next pair. In this case, since no pair other than the above-mentioned device has been set, it is determined that there is no next pair. The process ends.

As described above, when the CS tuner 1 transmits the information set for each connected device to the VTR 3,
This is performed using a default connection command (Default Connection Command) as shown in FIG. opecod
e indicates that the command is a default connection command, and Operand “0” indicates a subfunction (s
ubfunction), Operand “1” indicates a plug number (Plug No), and Operands “2” to “n” indicate a plug type (Plug type dependent field).

In the sub-function of Operand "0", data as shown in FIG. 19 is written. That is, set up the Output plug, set up the Output plug with protection settings,
For example, release the Output plug. Similarly, Inpu
The t plug is also defined.

The plug number of Operand "1" specifies a plug to be controlled. This designation is defined according to the table shown in FIG. Operand is a plug type that is more set with this plug number.
The format of the plug type field after “2” is determined.

The plug type fields of Operand "2" to "n" are defined by the table shown in FIG. This is a field determined by the plug type, as described above. Operand "2" is a field for designating a data rate, and is defined by the table shown in FIG. Operands “2” and “3” are nodes of a node that has a plug with the partner when setting a connection with node id.
Specify id. Operand “5” specifies the plug number of the plug that is the partner of the plug specified by Operand “1” when setting the connection. The plug number follows the regulation of Operand “1”. Also, both plugs,
They must be the same, one is an Input plug and the other is an Output plug.

In IEEE1394, when a bus reset occurs, all the default connections set before that are cleared. The default connection status command (Default Connection Sta
tus Command) is used to return the setting status of the default connection to the plug.

When a command having such a format is received, the receiving device transmits a default connection response (Default Connection Response) having a format as shown in FIG. 24 to the device which has transmitted the command. I do. If a plug is set, the corresponding code in Subfunction
Output Plug Setup, Output Plug Set shown in FIG.
up with Lock, InputPlug Setup, Input Plug Setup wi
th Lock is written, and its parameter is written in Plug type dependent field.

If the plug has not been set, the Subf
The Out code shown in FIG. 19 as a code corresponding to the unction
Put Plug Clear, Input Plug Clear are written, Plug
The value FFh is set in the type dependent field.

By using such a default connection command, the CS tuner 1, VTR 3, and V
The connection between TR3 and VTR4 is made. First, the connection between the CS tuner 1 and the VTR 3 will be specifically described with reference to FIG. Here, the physical ID of CS tuner 1
Is set to “0XFFC0” and the physical ID of VTR3 is set to “0XFFC0”.
FFC1. "

In this connection, data is output from the CS tuner 1 and the VTR 3 is a connection for inputting the data. Therefore, an output plug is set in the CS tuner 1 and an input plug is set in the VTR 3. Is done. In order to set and connect a plug in this way, in the example of FIG. 25A, (Plug
0, S200, 0XFFC0, Plug0, U) are transmitted from the CS tuner 1 to the VTR 3.

The default connection command is
Since this is done using Input Plug Setup, the array is (Input Plug No, data transfer speed, Physical ID of data output source, Output Plug No, Lock / Unloc
k). Each data of such a command is set in the CS tuner 1 based on the flowchart shown in FIG. 15 described above, and transmitted to the VTR 3. That is, “Input Plug No” is the input plug number of the VTR 3 set in step S101, and “Data transfer speed” is set in step S1.
04 is the data transmission speed between the CS tuner 1 and the VTR 3 which has been set and has already been obtained by the processing of the flowcharts of FIGS. 11 and 12.

“Physical ID of data output source” is the physical ID of CS tuner 1 set in step S102.
D, and when this Physical ID is set, the output destination Ph
The ysical ID or the physical ID of the output source is also set. In other words, data to be written to Operand “0” is also set. “Output Plug No” is the output plug number of the CS tuner 1 set in step S103. “Lock / Unlock” is data indicating whether or not the parameters set by the default connection command are protected.

Upon receiving such a default connection command, the VTR 3 returns an ACCEPT signal to the CS tuner 1 indicating that the command has been received.
As a result, the VTR 3 is a Point to Point Connection
Is set, and as shown in FIG. 25B, Output Plug 0 is set in the CS tuner 1 and Input Plug 0 is set in the VTR 3 for the plug. Data is transmitted and received between the devices using the set plug.

Next, the connection between VTR3 and VTR4 will be described with reference to FIG. In this case, the VTR 3 outputs data, and the VTR 4 (Physical ID is 0XFFC2)
Input that data, an output plug is set in the VTR 3 and an input plug is set in the VTR 4. Because the plug is set in this way, the CS tuner 1
The default connection command is (Plug1, S
400,0XFFC2, Plug3, U) to the VTR3.

The default connection command is
This is performed by Output Plug Setup (data written to Operand “0”). Therefore, the above-mentioned command arrangement is in the order of (Output Plug No, data transfer speed, Physical ID of data output destination, Input Plug No, Lock / Unlock). When the VTR 3 receives such a command, it transmits an ACCEPT signal to the CS tuner 1.
Then, the VTR 3 performs a Point to
Set Point Connection.

That is, the VTR 3 sets itself as Output Pl.
Set ug1 to VTR4 (Physical ID is 0XFFC2)
Set Input Plug3. The data transfer speed between these devices is S400. In this connection, the parameters of the default connection are not protected (Unlock).

Next, an example in which the parameters of the default connection are protected will be described with reference to FIG. From CS tuner 1, (Plug1, S400, 0XFFC4, Plug
3, L) is VTR by Output Plug Setup with Lock
3 is transmitted. Here, there is a controller having a physical ID of 0XFFC4.

The above-described default connection command sets the output plug 1 in the VTR 3 and sets the
The nput plug 1 is set, and the eta transfer speed between them is specified to be performed in S400, and it is instructed to protect (lock) these parameters. Therefore, FIG.
As shown in (B), a new output plug is set from the controller to the VTR 3, for example,
Even if the default connection command of (Plug0, S100, 0XFFC2, Plug0, U) is transmitted, the VTR 3 cannot accept the command (Rejec
The signal t) is sent to the controller.

As described above, VTR from CS tuner 1
3 sends a default connection command to
Based on the command, VTR3 is set to Point to Point Connec
The operation of this VTR3 is shown in Fig. 2.
This will be described with reference to the flowchart of FIG.

First, in step S111, the user
Operate the VTR3 and set the input / output to digital input. When digital input and setting are performed, step S
At 112, a channel is acquired for performing isochronous communication. In this channel, the same number as the connection destination is set. Then, in step S113, the bandwidth required for isochronous communication is calculated at the specified data transfer speed, and the calculated bandwidth is obtained.

In step S114, CMP (Conn
Section Management Protocol)
Set Connection. Thus, VTR3 is
Thus, CS tuner 1 and VTR 4 have C
The connection is set according to the parameters of the default connection command transmitted by the S tuner 1. By establishing a connection in this manner, data can be exchanged.

Next, the user selects a device to be connected from the display screen of the monitor 2 shown in FIG. 16, a default connection command is transmitted to the selected device, and processing until a connection is set is performed. , Will be described with reference to FIGS.

Assuming that the user has set the connection between the CS tuner 1 and the VTR 3 and the connection between the VTR 3 and the VTR 4 as connected devices from the screen shown in FIG. Is set and transmitted to the VTR 1. In FIG. 29, since the CS tuner 1 is the side that sends the default, the default is not specified. VTR3 has
The default designation transmitted from the CS tuner 1 is set. Similarly, a default designation from the CS tuner 1 is set in the VTR 4 as well.

In FIG. 30, when the VTR 3 is switched to a digital input, the VTR 3 communicates with the communication partner (CS tuner 1) set in the default designation column.
Create a PointConnection. When establishing a connection, a channel and a band are acquired. In the example of FIG. 30, 62 is set as the channel. Since the CS tuner 1 outputs data, the OPCR (Output Plug Control
Register) is set to 62. Since VTR3 is the data input side, IPCR (Input Plug Control Registry)
62 is set in the column of r).

Further, in FIG. 31, when the VTR 4 is also switched to the digital input, a connection with the VTR 3 is established by the same operation as that performed by the VTR 3. In this case, 61 is set in the OPCR column of VTR3, and 61 is also set in the IPCR column of VTR2. With this setting, the data output from the CS tuner 1 is stored in the VTR 3
And the data output from the VTR 3 can be input to the VTR 4.

Further, in FIG. 32, it is assumed that the setting of the digital input of the VTR 3 has been released by the user. In accordance with this release, the VTR 3 releases the connection established with the CS tuner 1. At this time, the channel and the band are also released. Therefore, the data output from the CS tuner 1 is no longer input to the VTR 3.

In FIG. 33, when the setting of the digital input of the VTR 4 is also released, the connection established with the VTR 3 is also released.

As described above, the CS tuner 1 sets parameters required for connection, transmits the parameters to the devices that need them as needed, and the device that receives the parameters sets the parameters to the parameters. Accordingly, since a connection is established between the devices, the processing of the connection between the devices can be reduced.

[0134] In the present specification, a providing medium for providing a user with a computer program for executing the above-mentioned processing includes an information recording medium such as a magnetic disk and a CD-ROM, and a network such as the Internet and a digital satellite. Transmission media is also included.

[0135]

According to the information processing system according to the first aspect, the information processing method according to the fifth aspect, and the providing medium according to the sixth aspect, the first information processing apparatus performs the second information processing. A parameter necessary for connecting the processing device to another information processing device is transmitted to the second information processing device, and the second information processing device communicates with another information processing device based on the received parameter. Since the band and the channel are secured during the period, the connection processing between the devices can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an information processing system to which an information processing apparatus of the present invention is applied.

FIG. 2 is a block diagram showing an internal configuration of a CS tuner.

FIG. 3 is a block diagram showing an internal configuration of a VTR.

FIG. 4 is a flowchart illustrating a process at the time of a bus reset.

FIG. 5 is a diagram illustrating an example of the configuration of a Self ID packet.

FIG. 6 is a diagram illustrating components of a Self ID packet.

FIG. 7 is a flowchart illustrating a tree structure analysis process.

FIG. 8 is a diagram showing data stored in a RAM of a CS tuner.

FIG. 9 is a diagram illustrating a tree structure of a bus.

FIG. 10 is a flowchart illustrating a process for determining the number of hops.

FIG. 11 is a flowchart illustrating a data transfer speed determination process.

FIG. 12 is a flowchart following FIG. 9;

FIG. 13 is a diagram illustrating the configuration of a node unique ID.

FIG. 14 is a flowchart illustrating a process of reading a node unique ID.

FIG. 15 is a flowchart illustrating a connection setting process between devices.

16 is a display example of a screen displayed on the monitor 2. FIG.

FIG. 17 is a flowchart illustrating a connection setting process performed by a CS tuner.

FIG. 18 is a diagram showing a format of a default connection command.

FIG. 19 is a diagram illustrating a Subfunction field.

FIG. 20 is a diagram illustrating data described in Operand “1”.

FIG. 21 is a diagram illustrating data described in Operand “2”.

FIG. 22 is a diagram illustrating the contents of a data rate.

FIG. 23 is a diagram illustrating a format of a status command of a default connection.

FIG. 24 is a diagram illustrating a format of a response of a default command.

FIG. 25 is a diagram illustrating how to establish a connection using a default connection command.

FIG. 26 is a diagram illustrating how to establish another connection using a default connection command.

FIG. 27 is a diagram illustrating how to establish another connection using a default connection command.

FIG. 28 is a flowchart illustrating a process performed by the VTR 3 for establishing a connection.

FIG. 29 is a diagram illustrating operations of a CS tuner, VTR3, and VTR4.

FIG. 30 is a diagram illustrating operations of a CS tuner, VTR3, and VTR4.

FIG. 31 is a diagram illustrating operations of a CS tuner, VTR3, and VTR4.

FIG. 32 is a diagram illustrating the operation of the CS tuner, VTR3, and VTR4.

FIG. 33 is a diagram illustrating the operation of the CS tuner, VTR3, and VTR4.

[Explanation of symbols]

1 CS tuner, 2 monitors, 3, 4 VTR,
5 1394 bus, 11CS tuner main part, 12
CPU, 13 RAM, 14 GUI engine, 51
Cursor, 52 command button, 53 connection selection button

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Michio Miyano 6-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (6)

[Claims] A first information processing device that manages connection between a plurality of information processing devices connected to a bus;
An information processing system including a second information processing apparatus connected and managed by the first information processing apparatus, wherein the first information processing apparatus connects the second information processing apparatus to another information processing apparatus. Setting means for setting parameters necessary for performing the setting, and setting the parameters set by the setting means to the second
Transmitting means for transmitting to the information processing apparatus, the second information processing apparatus comprises: receiving means for receiving a parameter transmitted by the transmitting means; and a parameter based on the parameter received by the receiving means.
An information processing system comprising: a securing unit that secures a band and a channel between the other information processing apparatus. 2. The method according to claim 1, wherein the transmitting unit is a Default Connection
2. The transmission using a command.
An information processing system according to claim 1. 3. The parameter is obtained by analyzing a tree structure of a bus from a Self ID packet received at a bus reset,
2. The information processing system according to claim 1, wherein the information is determined by analyzing a data transfer speed between predetermined information processing apparatuses. 4. The information processing apparatus according to claim 1, wherein the first information processing device includes: a display control unit configured to perform control for displaying a connectable information processing device among the plurality of information processing devices; and a screen displayed by the display control unit. 2. The information processing system according to claim 1, further comprising: a selection unit configured to select a connected device, wherein the setting unit sets a parameter for the information processing device selected by the selection unit. 3. 5. A first information processing device for managing connection between a plurality of information processing devices connected to a bus,
In an information processing method for an information processing system including a second information processing apparatus that is connected and managed by the information processing apparatus, the information processing method for the first information processing apparatus includes: a second information processing apparatus; A setting step of setting parameters necessary for connecting to another information processing apparatus; and setting the parameters set in the setting step to the second
The information processing method of the second information processing apparatus, wherein: a receiving step of receiving the parameter transmitted in the transmitting step; and a receiving step of receiving the parameter transmitted in the transmitting step. On the basis of,
An information processing method, comprising: securing a band and a channel with the another information processing apparatus. 6. A first information processing device for managing connection between a plurality of information processing devices connected to a bus,
In a providing medium for providing a computer program to an information processing system including a second information processing apparatus connected and managed by the information processing apparatus, the first information processing apparatus includes: A setting step of setting parameters necessary for connecting to another information processing apparatus; and setting the parameters set in the setting step to the second
A transmitting step of transmitting to the second information processing apparatus, a receiving step of receiving the parameter transmitted in the transmitting step, and
A providing medium for providing a computer-readable program for executing a process including a securing step of securing a band and a channel with the another information processing apparatus.