JPH10271139A - Information processor and connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to communicate with another information processor even in the state of turning off the power source of information processor to become an intermediate node connected by a DV cable. SOLUTION: In the state of turning on the power source of information processor D to become the intermediate node, the ON state of power source is detected by a power source state detection part 101, and since control is performed so as to open all switches from 100-a to 100-d at a switch part, information processors A, B and D perform communication as usual. In the state of turning off the power source of information processor D, the power source state detection part 101 detects the OFF state of power source and all the switches from 100-a to 100-d at the switch part 100 are closed. As a result, the information processors A and B can performs the communication through the switch part 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an information processing apparatus, and more particularly, to an information processing apparatus having an IEEE 1394 interface.

[0002]

2. Description of the Related Art Information processing apparatuses for handling digital data (for example, personal computers and DVDs (Digital
Versatile Disk) is attracting attention as an interface for connecting the IEEE 1394 high performance serial bus (hereinafter abbreviated as IEEE 1394).

The IEEE 1394 has two types of data transfer modes. That is, there are an Asynchronous transfer mode used for normal data transfer and an Isochronous transfer mode used for multimedia data transfer such as moving images and audio. In particular, the point that an isochronous transfer mode is provided is a point that is significantly different from other interfaces. In the isochronous transfer mode, it is ensured that data such as video and audio data, whose transfer delay is fatal, is reliably transferred within a predetermined time. It is suitable for frequently used, for example, a multimedia system.

[0004] IEEE 1394 supports two types of connection systems, a "daisy chain system" and a "node branching system". In the daisy chain system, up to 16 nodes (Node: equipment having an IEEE 1394 interface) can be connected to each other. In the node branching method, it is possible to connect a plurality of information processing devices as a node (or a leaf) branching from a certain information processing device as a root (Root). In IEEE 1394, since a 6-bit node number is assigned to each node, a maximum of 63 nodes (information processing devices) can be connected except for the last node number 63 used for broadcasting. It is possible.

FIG. 3 shows that a plurality of information processing apparatuses are IEEE1
FIG. 14 is a diagram illustrating a connection example in the case where they are connected to each other via 394. As shown in this figure, the IEEE 1394 interface of each information processing apparatus is a physical (PH)
It is composed of a Y) layer and a link (LINK) layer.
The physical layer determines the encoding method of the serial signal and the electrical specification of the signal. Also, the link layer
A protocol for low-level processing such as reading and writing is defined. Each of the physical layer and the link layer is a dedicated LSI (Large
Scale Integrated Circuit).

In the example shown in FIG. 3, information processing apparatuses (nodes) 1 to 3 are respectively constituted by physical layers 1-a to 3-a and link layers 1-b to 3-b. The information processing apparatus 1 is connected to another information processing apparatus (not shown) by an IEEE 1394 cable (hereinafter abbreviated as a cable) 4 and is connected to the information processing apparatus 2 by a cable 5. The information processing device 2 is mutually connected to the information processing device 1 by a cable 5, to the information processing device 3 by a cable 6, and to another information processing device (not shown) by a cable 7. Further, the information processing device 3
Are connected to the information processing device 2 by a cable 6.

FIG. 4 is a diagram illustrating the structure of a cable and a connector. As shown in this figure, pins 1 to 6 are built in the connectors 20 and 21, respectively. A positive power is supplied to the pin 1, and the pins 1 of the connectors 20 and 21 are connected to each other via a power line 23. The pin 2 is a power supply ground, and is connected to each other via a power supply line 24. The shields 26 and 27 inside the cord are also set to the same potential as the power supply line 24.

The pins 3 and 4 of the connector 20 are connected to the signal line 28 and the pins 5 and 6 of the connector 21. Note that the signal line 28 is a stranded wire that is mutually twisted, and is disposed inside the shield 27. Pins 5 and 6 of connector 20
Is connected to the signal line 25, and is connected to the pin 3 of the connector 21.
And pin 4. The shield 22 is set to the same potential as the housing of the connectors 20 and 21. The signal line 25 and the signal line 28 transmit signals by a balanced transmission method (a method of amplifying and transmitting a signal symmetrically in both positive and negative directions with a ground as a reference level).

FIG. 5 shows a sectional view of the cable shown in FIG. As shown in this figure, the shield 22 is disposed inside the outermost insulating layer 30. Shield 2
2, power supply lines 23 and 24 and shield 2
6, 27 are arranged. Inside the shield 26,
The signal lines 25 formed by twisting each other are arranged. Similarly, inside the shield 27, a signal line 28 formed by twisting each other is arranged.

As shown with reference to FIGS. 4 and 5,
The IEEE 1394 cable incorporates not only a signal line but also a power cable. Therefore, when a plurality of information processing apparatuses are connected to each other, even when some of the information processing apparatuses are turned off, the power supply line is connected to the information processing apparatuses in the off state. Since power can be supplied via the power supply, information can be transmitted.

[0011] Such a case will be described with reference to FIG. In this example, six information processing apparatuses (nodes A to F) are connected to each other, and all the power supplies other than the information processing apparatus corresponding to the node B are turned on. In such a case, the LS configuring the physical layer of Node B
I is the power line 23 and the power line 2 of the cable shown in FIG.
4 is supplied with power from any one of the remaining nodes. Therefore, even when the power of the node B is turned off, for example, the node F can communicate with the node A.

[0012]

By the way, in order to apply to consumer appliances (for example, home video cameras), it is necessary to reduce the size of the connector and the cable. Therefore, power supply lines 23 and 2 for power supply
4 (Digital Video) cable without DV.

FIG. 7 is a diagram for explaining the structure of the DV cable and the connector. In this figure, the parts corresponding to the IEEE 1394 cable shown in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted.

As shown in FIG.
41 includes pins 1 to 4 respectively. The pin 1 and the pin 2 of the connector 40 are connected to the pin 1 and the pin 2 of the connector 41 via a signal line 25 formed by twisting each other. Pins 3 and 4 of the connector 40 are
A signal line 28 also formed by twisting each other.
Are connected to pins 3 and 4 of the connector 41. Note that the signal line 25 and the signal line 28 are disposed inside the shield 26 and the shield 27, respectively.

The shield 22 is connected to the connector 4
It is set to the same potential as the housings 0 and 41. The signal line 2
The signal transmission line 5 and the signal line 28 transmit a signal by a balanced transmission method (a method of amplifying and transmitting a signal symmetrically in both positive and negative directions with a ground as a reference level).

However, when such a DV cable is used, when the power of the information processing apparatus is turned off, power is not supplied to the physical layer of the information processing apparatus, and the other information processing apparatuses are not supplied with power. However, there has been a problem that communication cannot be performed via the information processing device. An example of such a case will be described below.

FIG. 8 shows a case where the information processing apparatus A (not shown) and the information processing apparatus B (not shown) are interconnected by a DV cable so that the information processing apparatus D is an intermediate node. FIG. 3 is a diagram showing a connection relationship of FIG.

FIG. 8A shows that the power of the information processing apparatus D is O
A case where the state is N is shown. The physical layer 40 of the information processing device D includes a DV cable 50 including signal lines 50-a to 50-d, and a signal line 60-a.
To the DV cable 60 composed of the cable 60-d. The physical layer 40 includes an LSI 41
And an LSI 42, which are supplied with power from the power supply of the information processing apparatus D.

FIG. 8B shows that the power of the information processing apparatus D is O
This shows a case where the state is FF. in this case,
Since power is not supplied to the LSI 41 and the LSI 42 of the physical layer 40, the connection between the information processing apparatus A and the information processing apparatus B is cut off, and communication between the two information processing apparatuses is performed. You will not be able to do it.

The present invention has been made in view of the above situation, and an information processing apparatus serving as an intermediate node is provided with a DV.
When connected to another information processing device using a cable, the power of the information processing device serving as an intermediate node is turned off.
Even when the state is FF, communication between other information processing apparatuses is enabled.

[0021]

According to a first aspect of the present invention, there is provided an information processing apparatus, comprising: detecting means for detecting whether the power of the information processing apparatus is ON or OFF; Intermittent means for connecting or disconnecting the signal line and the corresponding signal line of the second DV terminal, respectively, wherein if the detecting means detects that the information processing apparatus is powered on, the Means for shutting off each signal line of the first DV terminal and a corresponding signal line of the second DV terminal, respectively, and detecting means for turning off the power supply of the information processing apparatus.
When the state of F is detected, each signal line of the first DV terminal is connected to the corresponding signal line of the second DV terminal by the intermittent means.

According to a second aspect of the present invention, in the connection method, a detecting step of detecting whether the power of the information processing apparatus is ON or OFF, each signal line of the first DV terminal,
An intermittent step of connecting or disconnecting the corresponding signal line of the second DV terminal. If the detecting step detects that the power of the information processing apparatus is ON, the intermittent step performs the first intermittent step. The signal lines of the DV terminal and the corresponding signal line of the second DV terminal are cut off, and the power supply of the information processing apparatus is turned off by the detection step.
When the state of F is detected, each signal line of the first DV terminal and a corresponding signal line of the second DV terminal are connected in an intermittent step.

In the information processing apparatus according to the first aspect, the detecting means detects whether the power of the information processing apparatus is ON or OFF, and outputs each signal line of the first DV terminal to the first DV terminal. The second DV terminal and the corresponding signal line are connected or disconnected by the intermittent means, respectively, and when the detecting means detects that the power of the information processing apparatus is ON, the first DV terminal is connected by the intermittent means. Each signal line and the second
And the corresponding signal line of the DV terminal is disconnected, and when the power supply of the information processing apparatus is turned off by the detection means, the first DV
Each signal line of the terminal is connected to a corresponding signal line of the second DV terminal. For example, in the case where the second information processing device and the third information processing device are connected to the first DV terminal and the second DV terminal of the first information processing device via a DV cable, respectively, When the power of the information processing device is turned on, the detecting means detects that the information processing apparatus is on, and the intermittent means detects the corresponding signal lines of the first DV terminal and the corresponding signal of the second DV terminal. When the line connection is interrupted and the power of the first information processing apparatus is turned off, the detecting means detects that the power is off, and the intermittent means detects each signal of the first DV terminal. The line and the corresponding signal line of the second DV terminal are connected.

[0024] In the connection method according to the second aspect, the detecting step detects whether the power of the information processing apparatus is ON or OFF, and detects each signal line of the first DV terminal and the second DV terminal. And the corresponding signal line of the DV terminal are connected or disconnected, respectively. If the detecting step detects that the power of the information processing apparatus is in the ON state, the connecting and disconnecting step connects and disconnects the first DV terminal. Each signal line and the corresponding signal line of the second DV terminal are cut off, and the power of the information processing apparatus is turned off by the detection step.
Is detected, each signal line of the first DV terminal is connected to the corresponding signal line of the second DV terminal in an intermittent step. For example, a DV terminal is connected to a first DV terminal and a second DV terminal of the first information processing device.
In a case where the second information processing apparatus and the third information processing apparatus are connected via a cable, respectively, when the power of the first information processing apparatus is turned on, the detection step turns on the first information processing apparatus. Is detected, the connection between each signal line of the first DV terminal and the corresponding signal line of the second DV terminal is interrupted by the intermittent step, and the power of the first information processing device is turned off. Then, the detection step detects the OFF state, and the intermittent step connects each signal line of the first DV terminal to the corresponding signal line of the second DV terminal.

[0025]

FIG. 1 is a diagram showing a configuration example of an embodiment of the present invention. In this figure, parts corresponding to the case shown in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, as compared with the case of FIG. 8, a switch unit 100 (intermittent means) composed of switches 100-a to 100-d, and
Power supply state detection section 101 (detection means) for detecting FF state
Has been newly added. Other configurations are the same as those shown in FIG.

FIG. 2 is a diagram showing a detailed configuration example of the switch section 100 and the power supply state detecting section 101. In this figure,
Although only the switch 100-a of the switch unit 100 is illustrated, the other switches 100-b to 100-d have the same configuration.

The power supply state detector 101 includes a resistor 101-
a, a transistor 101-b (detection means), and a resistor 101-c. Switch 1
00-a is composed of a Zener diode 100-a-1 and a relay 100-a-2 (intermittent means).

The resistance 101-a of the power supply state detection unit 101
Is a base protection resistor of the transistor 101-b,
An excessive current is prevented from flowing into the base. The transistor 101-b detects whether or not the power of the information processing apparatus D is in the ON state.
When the state is N, a predetermined voltage is output to the switch 100-a. The resistor 101-c is an emitter resistor,
1-b constitutes an emitter follower circuit.

The Zener diode 100-a-1 protects the transistor 101-b from being damaged by the high voltage generated by the self-induction of the electromagnet of the relay 100-a-2. That is, when a predetermined voltage or more is applied to the input terminal of the electromagnet of the relay 100-a-2, the Zener diode 100-a-1 limits this voltage.

The relay 100-a-1 includes a resistor 101-c.
When the output voltage is applied to both ends of the resistor 101-c, the output voltage is zero.
In the case of V, the contacts are closed.

Next, the operation of the above embodiment will be described.

Assuming that the power supply of the information processing apparatus D shown in FIG. 1 is turned on, the power supply voltage (DC) is applied to the collector of the transistor 101-b of the power supply state detection unit 101 and one terminal of the resistor 101-a. Voltage) is applied. The other terminal of the resistor 101-a is at a ground level because there is no output at this time, and thus a predetermined current flows toward the base. As a result, a predetermined current (a current obtained by amplifying the base current with a predetermined gain) flows between the collector and the emitter of the transistor 101-b. Then, a predetermined output voltage is generated between both ends of the resistor 101-c.

The output voltage generated between both ends of the resistor 101-c is connected to the Zener diode 100-a-1 and the relay 100-a-1.
-A-2. Zener diode 10
Since the Zener voltage of 0-a-1 is set to be considerably higher than the output voltage of the normal level, the voltage applied to both ends of the Zener voltage is directly applied (without voltage drop) to the relay 10.
0-a-2. When an output voltage is applied to the relay 100-a-2, the contact is opened (in FIG. 1, the switch 100-a is opened), so that the signal line 50- from the information processing apparatus A is opened. a is LSI
41, and a signal line 6 from the information processing apparatus B.
0-a is also connected to the LSI 41.

At this time, power is supplied to the physical layer 40 of the information processing apparatus D from the power supply unit.
Since 00-b to 100-d are also set to the open state under the control of the power supply state detection unit 101, the DV cable 50 from the information processing apparatus A and the DV cable 60 from the information processing apparatus B It will be connected to the physical layer. Therefore, in this case, information can be transmitted and received between the information processing apparatuses A, B, and D as usual.

Next, the case where the information processing apparatus D is turned off will be described. When the power is turned off, the voltage applied to the resistor 101-a of the power state detection unit 101 becomes 0V, and the voltage applied to the collector also becomes 0V. The voltage output to both ends is also 0V. As a result, relay 1
No current is supplied to the electromagnet 00-a-2.

At this time, in the electromagnet of the relay 100-a-2, the current flowing immediately before is suddenly cut off, so that a large voltage is generated by self-induction. However, since the voltage thus generated is absorbed by the Zener diode 100-a-1,
The transistor can be prevented from being damaged.

When no current is supplied to the electromagnet of the relay 100-a-2, the switch is closed. As a result, the switch 100-a shown in FIG. 1 is closed, so that the signal line 50-a of the information processing device A and the signal line 60-a of the information processing device B are directly connected. The same control is performed on the switches 100-b to 100-d, and these are all closed, so that the information processing apparatus A and the information processing apparatus B can communicate via the switch unit 100. It becomes possible.

According to the above-described embodiment, even when the information processing apparatus is connected to another information processing apparatus by a DV cable and the power of the information processing apparatus serving as an intermediate node is turned off, It is possible to perform communication with the information processing apparatus of the normal manner.

In the above embodiment, the signal line is connected or disconnected by the relay 100-a-2.
Needless to say, Effect Transistor)) may be used.

[0041]

According to the information processing apparatus according to the first aspect and the connection method according to the second aspect, whether the power of the information processing apparatus is ON or OFF is detected. When it is detected that the power supply of the information processing device is in the ON state, the signal lines of the first DV terminal and the corresponding signal lines of the second DV terminal are cut off, respectively. Is detected to be in the OFF state, each signal line of the first DV terminal is connected to a corresponding signal line of the second DV terminal.
Even when the power of the information processing device that is the intermediate node is turned off, communication can be performed between other information processing devices.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a detailed configuration example of a switch unit 100 and a power supply state detection unit 101 shown in FIG.

FIG. 3 is a diagram illustrating a connection state when a plurality of information processing apparatuses are mutually connected via an IEEE 1394 cable.

FIG. 4 is a diagram showing a connection state between a signal line inside an IEEE 1394 cable and a pin inside a connection connector.

FIG. 5 is a sectional view showing a section of an IEEE 1394 cable.

FIG. 6 is a diagram illustrating an example in which a plurality of information processing apparatuses are connected to each other via an IEEE 1394 cable;
It is a figure which shows the state at the time of setting it to the state of F.

FIG. 7 is a diagram showing a connection state between a signal line inside a DV cable and a pin inside a connection connector.

FIG. 8 is a diagram illustrating a connection relationship when the information processing apparatus A and the information processing apparatus B are connected via a DV cable with the information processing apparatus D as an intermediate node.

[Explanation of symbols]

40 physical layer, 50 DV cable, 60 DV cable, 100 power state detection unit (detection means), 1
00-a-2 relay (intermittent means), 101 switch section (intermittent means), 101-b transistor (detection means)

Claims (2)

[Claims] 1. An I-terminal having two DV cable connection terminals.
An information processing apparatus having an IEEE 1394 interface, comprising: a detecting unit configured to detect whether a power supply of the information processing apparatus is in an ON state or an OFF state; a signal line of a first DV terminal; Connecting and disconnecting means for respectively connecting and disconnecting the corresponding signal line; and when the detecting means detects that the power of the information processing apparatus is in an ON state, the connecting and disconnecting means sets the first DV. The signal lines of the terminals and the corresponding signal lines of the second DV terminal are cut off respectively, and the power of the information processing device is turned off by the detection means.
Is detected, the intermittent means connects each signal line of the first DV terminal to the second DV terminal.
An information processing apparatus, wherein each signal line is connected to a corresponding signal line of a V terminal. 2. An I-port having two DV cable connection terminals.
A method of connecting an information processing device having an IEEE 1394 interface, a detecting step of detecting whether the power of the information processing device is ON or OFF; a signal line of a first DV terminal; An intermittent step of connecting or disconnecting a corresponding signal line of a DV terminal, respectively, wherein the power of the information processing apparatus is turned on by the detecting step
Is detected, the intermittent step interrupts each signal line of the first DV terminal and the corresponding signal line of the second DV terminal, respectively, The power of the information processing device is O
When the state of the FF is detected, each signal line of the first DV terminal is connected to a corresponding signal line of the second DV terminal in the intermittent step. Connection method to be used.