JPH11345193A - Serial bus interface device, constituting method for bus, recording medium, and serial bus interface system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the exchange of a signal for identifying a tree structure s disabled when non-permitted connection configuration is adopted in connection between devices, resulting in data communication between the devices becoming unavailable. SOLUTION: The additional connection or disconnection of a device is detected, a bus is constituted and when constituting the bus, the existence of a loop-connected device on an interface system is detected. A parent notify signal is forcedly generated from a port to be the port of connection with another device, and the parent notify signal is received from the port. The spot of loop connection generation is decided from the transmission and reception conditions of the signal and based on the decision result, active ports are disabled. After the port is disabled, the bus constitution is restarted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial bus interface and, more particularly, to a device and bus configuration method.
The present invention relates to a recording medium and a serial bus interface system using the device.

[0002]

2. Description of the Related Art In recent years, serial buses have few signal lines, thin cables, small connectors, and IDs.
It has been spotlighted because of its excellent features, such as the necessity of setting of a power supply and a terminator, the possibility of hot-swapping, and the capability of isochronous data transfer (isochronous transfer).

[0003] In particular, the IEEE1394 serial bus is capable of high-speed transmission of large-capacity data such as moving images, and is capable of memory access by a bus architecture.
Features such as hot plug-in, plug-and-play, and peer-to-peer connection enable not only personal computers but also home AV equipment (such as digital video cameras) and Application to other devices is being actively promoted.

[0004] Further, formulation of new standards corresponding to further speeding-up and longer distances is currently being vigorously pursued.

A configuration example of the IEEE1394 bus will be described with reference to FIG.

Reference numerals 1701 to 1708 denote devices (nodes) connected by a daisy chain or branches by an IEEE1394 interface. As the device, various devices such as a computer, a digital video camera, a CCD camera, a printer, a scanner, and a storage device can be considered. IEEE1394 ports are two twisted pair cables (one is called A and the other is called B)
And one set of power pair cables. The two sets of twisted pair cables are connected by crossing each other with a cable. One A is connected to the other B, and one B is connected to the other A. Is done. The data signal is a half-duplex communication. The twisted pair A transmits a data signal, the twisted pair B transmits a strobe signal as a differential signal, the twisted pair A receives a strobe signal, and the twisted pair B receives a data signal as a differential signal. The arbitration signal is a full-duplex communication, in which an arbitration signal is transmitted from the driver side, and at the same time, three phases (0, 1, Z) defined by a certain voltage level on the receiver side.
The received arbitration signal is identified using the following logic. 3 above
In order to determine the phase logic, twist pair A has "Ar
b Rx ”, twisted pair B has“ Arb B
A comparator in which a non-inverting input and an inverting input are paired as Rx is prepared. "0" is defined as low voltage at non-inverting input and high voltage voltage at inverting input, "1" is defined as high voltage at non-inverting input and low voltage at inverting input,
"Z" is defined by the low voltage at both non-inverting and inverting inputs.

To establish a bus configuration, three phases of bus initialization, tree identification, and self-identification are performed. During the three-phase process, a tree-like topology as shown in FIG. 17 is built.

[0008] Here, the initialization of the bus depends on the case where it occurs due to power discontinuity, the case where it is generated by a software command, or the case where an abnormality in the bus configuration due to a new connection or disconnection of a node in the bus configuration is detected. This is completed when a bus reset occurs and all nodes become idle.

Specifically, first, a logical "1" is transmitted to both the twisted pair A and the twisted pair B to generate a bus reset, and the node receiving this signal recognizes the occurrence of the bus reset. When an arbitrary time elapses after the occurrence of the bus reset, the logic [Z] is transmitted to both the twisted pair A and the twisted pair B to generate an idle signal, and the system waits for the connected node to transmit the idle signal. When the idle signal is received from the node, it recognizes that the bus initialization has been completed.

When the initialization of the bus is completed, the process proceeds to the phase of tree identification.

The node has only one connection node to its own node, that is, a “Leaf” node configured as an end point on the bus and a “Bran” node having two or more connection nodes.
There are three types of nodes: a "ch" node and a "non-connection" node having no connection node, that is, a standalone connection.

In tree identification, first, a node transmits a Parent Notify signal to a node that is a parent (root) candidate. In FIG. 17, the “Leaf” node 17
04, 1706, 1707, 1708
Indicates that a rent Notify signal is being transmitted.
The "Branch" node does not know which port (node connected to that port) is a route candidate node when other devices are connected to multiple ports, so Parent Notify first. It will not send any signal, but will wait to receive a Parent Notify signal from the "Leaf" node. However, "Branch"
Even if a node has multiple ports, only one port is connected to another node and all other ports are not connected, or it is active even if there are multiple connected nodes If there is only one port (or the node to which that port is connected)
f "node.

Next, as shown in FIG.
Child noti acknowledges that the "Branch" node that received the otify signal is a child node to the transmitting node
Send the fy signal. Here, reference numerals 1801 to 1808 denote nodes. The “Leaf” node receives the Child notify signal and recognizes that the connection of the port has been completed. Specifically, the node 1802, which has received the Parent Notify signal from the node 1804,
Node 1804 that transmitted the tify signal and received the signal
Recognizes that the connection with the node 1802 is normally performed. Similarly, the same is done between nodes 1807, 1808 and 1805, and then between nodes 1806 and 1803.

[0014] The "Branch" node, as described above,
After transmitting a Child Notify signal in response to the nt Notify signal and recognizing that the connection of the node between the ports has been completed, the parent Notify signal is received among the ports that are active on the port of the own node. If there are only one port left, Parent Not for that port
Send ify signal.

In FIG. 18, nodes 1803 and 1804 perform the operation. More specifically, the node 1803 is a node having three ports and having two active ports, and connection of one of the ports is completed (connection with the node 1806), so the remaining one port (the connection node is 1801) ) To send a Parent Notify signal. Similarly, node 1805 is also connected to node 1802
Sends a Parent Notify signal to the As a result, the nodes 1801 and 1802 become final parent (root) candidates.

In FIG. 19, the node 1901 is
02 sends a Parent Notify signal to node 19
02 transmits a Child notify signal to the node 1901, which indicates that the node 1902 has been determined as the final parent “Root” node and that tree identification has been completed. Here, nodes 1901 to 1908 are nodes.

When the tree identification is completed, a node number is assigned to each node, and a phase of self-identification for enabling each other to perform data communication is started.

[0018]

However, in the above-mentioned prior art, since the connectors of the cables for connecting to other devices are all the same, the nodes 2003 and 2005 are connected as shown in FIG.
Are connected, an unacceptable loop connection other than the daisy chain connection and the branch connection is made to the nodes 2001 and 2001.
Node 2002, Node 2003 and Node 2005
Will be established between

In this loop connection, a plurality of ports of the "Branch" node wait for receiving a Parent Notify signal from another node.
No signal is sent and tree identification cannot be completed. For this reason, there is a problem that a state in which subsequent self-identification and data communication cannot be performed.

As a means for solving this problem, there is a method of detecting the occurrence of a loop connection and notifying the user by some means. However, the detection means performs time management using a timer, that is, a tree connection within a certain time. If it is considered that a loop connection has been detected on the bus when the identification phase has not been completed, it is not known where the loop connection occurred, and it is also possible to time out due to requirements other than the loop connection. If this is the case, it is difficult to reliably determine whether or not a loop exists (that is, reliable loop detection cannot be performed by time management using a timer).

Further, even when there are a plurality of loops in the configured bus, it cannot be detected (it is known that there is a loop connection but it is not known how many loops exist). Cannot identify the location. Furthermore, even if the detected location is accurately communicated, the user must perform the work of avoiding the loop connection by disconnecting the node, etc. There's a problem.

The present invention solves the above problem,
The bus is reconfigured by performing reliable loop detection and automatically avoiding the loop connection. In addition, it is possible to accurately notify the user of the location where the loop connection has occurred, including the case where reconfiguration is not possible.

[0023]

To achieve the above object, a serial bus interface device, a bus configuration method of the serial bus interface, a recording medium, and a system using the device according to the present invention have the following configurations. .

In other words, the serial bus interface device detects the additional connection and disconnection of the device and configures the bus, and determines the connection form of the device on the interface system and detects the presence of the device connected in a loop. Loop detection means, and one or more ports serving as connection ports for other devices,
Signal generating means for forcibly generating a Parent Notify signal from the port, signal receiving means for receiving a Parent Notify signal from the port, and determining means for determining the occurrence of a loop connection from the signal transmission and reception conditions ,
Disabling means for disabling an active port based on the determination result of the determining means, and system reconfiguration starting means for restarting the bus configuration means after disabling the port by the disabling means.

Preferably, the serial bus interface is based on IEEE1394.

Preferably, the loop detecting means comprises:
When the count value of the timer exceeds an arbitrary timer value, it is recognized that there is a device connected in a loop on the bus.

Preferably, the apparatus further comprises means for notifying a user of a loop detection result by the loop detecting means.

Preferably, the means for notifying the user of the loop detection result by the loop detecting means is based on a display on a display device.

Preferably, when the serial bus interface device is a printer and a device capable of printing on a medium, the result of the loop detection by the loop detecting means is printed out on the medium to notify the user.

Preferably, the means for notifying the user of a loop detection result by the loop detecting means is based on voice transmission.

Preferably, when there are a plurality of ports, loop detection is possible for each of the plurality of ports.

[0032] Preferably, said determining means includes:
When it is determined that the serial bus interface device is present on a bus forming a loop on the serial bus interface system, the system reconfiguration starting means disables a port, executes system reconfiguration, and executes a system reconfiguration. If it is determined that there is no loop connection, the display unit notifies the user only of the existence of the loop connection.

Preferably, the determination means generates a Parent Notify signal for a port that has not received a Parent Notify signal when a plurality of ports are active, and generates a Parent Notify signal for a port other than the port that transmitted the Parent Notify signal. Is received, it is determined that a loop exists on the bus connected between the ports.

Preferably, the signal generating means may generate a Parent Notify signal for a port that has not received a Parent Notify signal when a plurality of ports are active, or a Parent Notify signal from any other port. If a signal cannot be received, a Parent Notify signal is generated for another port that has not received the Parent Notify signal, and an operation for confirming the existence of a loop is performed.

Preferably, the determination means starts a timer with an arbitrary timer value when a Parent Notify signal is generated for a port that has not received a Parent Notify signal when an active port exists. And
Parent from any other port when the timer value is exceeded
When a Notify signal cannot be received, it is determined that a loop exists on a bus formed between devices connected to the end of the port.

Preferably, an arbitrary timer value used in the loop detecting means and an arbitrary timer value used in the judging means are set to different values, and activation of the loop detecting means and the judging means is performed. The feature is that the timing is changed.

[0037] Preferably, the information processing apparatus further comprises notifying means for notifying a user which port has been disabled when the port has been disabled by the disable means.

Further, the bus configuration method of the interface system includes a bus configuration step of detecting the additional connection or disconnection of a device to configure a bus, and a loop configured to detect the presence of a loop-connected device on the interface system when the bus is configured. A detecting step, a signal generating step of forcibly generating a Parent Notify signal from a port serving as a connection port with another device, a signal receiving step of receiving a Parent Notify signal from the port, and a transmission and reception state of the signal A determining step of determining the location of the occurrence of a loop connection from the above, a disabling step of disabling an active port based on the determination result of the determining step, and re-executing the bus configuration step after disabling the port by the disabling step. Starting the system reconfiguration.

Preferably, the loop detecting step comprises:
When the count value of the timer exceeds an arbitrary timer value, it is recognized that there is a device connected in a loop on the bus.

Preferably, the method further comprises a step of notifying a user of a loop detection result in the loop detecting step.

Preferably, in the step of notifying the user, a display notifies a result of the loop detection by the loop detecting step.

Preferably, when the device constituting the serial bus interface bus is a device capable of printing on a medium such as a printer, a method of printing and outputting a loop detection result by the loop detecting step to a medium is provided to a user. Notice.

Preferably, in the step of notifying the user, the result of the loop detection by the loop detecting step is notified by voice transmission.

[0044] Preferably, the loop detecting step includes:
Multiple loops can be detected.

Preferably, in the determining step,
When it is determined that the serial bus interface device is present on a bus forming a loop on the serial bus interface system, the system reconfiguration starting step disables a port, executes system reconfiguration, and executes the system reconfiguration. If not, the notifying the user notifies the user only of the existence of the loop connection.

Preferably, the determination step includes generating a Parent Notify signal for a port that has not received the Parent Notify signal when a plurality of ports are active, and transmitting a Parent Notify signal to a port other than the port that transmitted the Parent Notify signal. Is received, it is determined that a loop exists on the bus connected between the ports.

Preferably, in the signal generating step, when a plurality of ports are active, a Parent Notify signal is generated for a port that has not received a Parent Notify signal, and a Parent Notify signal is output from any other port. If a signal cannot be received, a Parent Notify signal is generated for another port that has not received the Parent Notify signal, and an operation for confirming the existence of a loop is performed.

Preferably, the determining step starts a timer with an arbitrary timer value when a Parent Notify signal is generated for a port that has not received the Parent Notify signal when an active port exists. And
Parent from any other port when the timer value is exceeded
When a Notify signal cannot be received, it is determined that a loop exists on a bus formed between devices connected to the end of the port.

[0049] Preferably, an arbitrary timer value used in the loop detecting step and an arbitrary timer value used in the judging step are set to different values, and activation of the loop detecting step and the judging step is performed. The feature is that the timing is changed.

[0050] Preferably, the method further comprises a notification step of notifying a user which port has been disabled when the port has been disabled by the disable step.

A computer-readable recording medium has a bus configuration step of detecting the additional connection or disconnection of a device to configure a bus, and a loop detection step of detecting the presence of a loop-connected device on the bus configuration interface system. And, a signal generating step of forcibly generating a Parent Notify signal from a port serving as a connection port with another device, a signal receiving step of receiving a Parent Notify signal from the port, and a loop from transmission and reception states of the signal. A judging step of judging a connection occurrence point, a disabling step of disabling an active port based on the judgment result of the judging step, and restarting the bus configuration step after disabling the port by the disabling step System reconfiguration start step.

A serial bus interface system in which a plurality of devices are connected by a serial bus interface device uses the serial bus interface device as the serial bus interface device.

Preferably, the device connected by the serial bus interface device has a printer function.

With this configuration, a reliable loop detection is performed, and the loop connection is automatically avoided without bothering the user to reconfigure the bus. In addition, it is possible to accurately notify the user of the location where the loop connection has occurred, including the case where reconfiguration is not possible.

[0055]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] The first embodiment of the present invention
Will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration in a device according to the first embodiment.

Reference numeral 101 denotes a node (device body) having an interface conforming to the IEEE1394 standard. It is composed of blocks 102, 105 to 113 described below. In this example, a scanner device that reads an image is assumed. In addition to this, as long as there is a device that can configure the IEEE1394 interface system, any function can be used as the function of the application that is the upper layer.

Reference numeral 102 denotes a receptacle serving as a receiving port (port) on the device body side of the IEEE1394 interface. Here, cables for connecting to various devices constituting the system are inserted.

Reference numeral 103 denotes a plug of an IEEE1394 interface cable. This part is connected to the ports of various devices.

Reference numeral 104 denotes an IEEE1394 interface cable. In this cable, a total of six cables including two twisted pair cables (one is a signal line called A and the other is a signal line called B) and one set of a power supply pair cable are crossed.

Reference numeral 105 denotes 100 Mbps conforming to IEEE1394.
Various hardware logics (multi-port of twisted pair interface, interface to link layer IC, synchronization and reconfiguration of packet data, bit-level arbitration, (Initialization logic, timer, etc., which are the gist of the present invention). Although the details of the function and the configuration are the gist of the present invention, the configuration will be described later in detail with reference to FIG. 2 and the processing flow thereof with reference to FIGS.

Reference numeral 106 denotes a controller of a link layer conforming to IEEE1394, which is constituted by various hardware logics.

Reference numeral 107 denotes various controls of this device and IE
It is a CPU that implements the functions of the transaction layer, node controller, and application layer of the EE1394 interface.

Reference numeral 108 denotes a RAM for storing commands and data required when the CPU 107 performs various processes.
It is also used for storing transfer data by the IEEE1394 interface and for temporarily storing images read by a scanner.

A ROM 109 stores control information of the present device. The control information can be updated later by using a flash memory or the like.

Reference numeral 110 denotes an ASIC for performing mechanical control of the device and various image processing. This is a dedicated hardware logic for performing various image processing such as control of a scanner head at the time of reading an image and correction of the read image data.

Reference numeral 111 denotes a scanner. It comprises a light source for reading a document, a CCD sensor, an A / D converter, an image signal correction circuit, and the like.

Reference numeral 112 denotes a user interface for notifying a user of a status and receiving a command input from the user. It comprises a display unit for notification and an operation unit for receiving input.

Reference numeral 113 denotes a system bus. In addition to the illustrated blocks 106 to 112, components not shown also hang on this bus, and high-speed data transfer between the blocks can be performed.

FIG. 2 is a configuration diagram of a PHY block according to the first embodiment.

Reference numeral 201 denotes hardware logic constituting a physical layer corresponding to a portion 105 in FIG. It is composed of blocks 207 to 208 and 212 to 214 described below.

Each of 202a, 202b and 202c is an IE
A receptacle that serves as a port (port) on the device body side of the EE1394 interface. Here, a cable for connecting to various other devices is inserted. In this embodiment, the device has three ports.

Reference numeral 203 denotes a plug of the IEEE1394 interface cable. This part is connected to the ports of various devices.

Reference numeral 204 denotes an IEEE1394 interface cable. In this cable, a total of six cables including two twisted pair cables (one is a signal line called A and the other is a signal line called B) and one set of a power supply pair cable are crossed.

Reference numeral 205 denotes a TpA signal from the TpA receiver. IEEE1394 devices use Tp for one port
It has two transceivers, A and TpB. T
The pA transmits an arbitration bit and a packet (strobe signal), and receives an arbitration signal and a packet (data signal).

Reference numeral 206 denotes a TpB signal from the TpB receiver. TpB transmits an arbitration bit and a packet (data signal) and receives an arbitration signal and a packet (strobe signal).

Reference numerals 207a, 207b, and 207c denote transmitters and receivers each including a driver for driving a differential signal, a wideband receiver with a low offset, and a conversion unit to a digital signal. Here IEEE13
It receives signals transmitted over cable 94 and converts data transmitted from the device into signals that flow through the cable.

Reference numeral 208 denotes a crystal oscillator.

Reference numeral 209 denotes a PLL for generating a clock having an operating frequency of the IEEE1394 interface from the output of the crystal oscillator 208.

Reference numeral 210 denotes an operation clock of the IEEE1394 interface. 100Mbps to 40 depending on the device
An operation clock of 0 Mbps is required.

Reference numeral 211 denotes a digital signal converted by the transmitter and the receiver 207. Various signals used in the configuration of the bus and data signals transmitted / received correspond thereto.

Reference numeral 212 denotes a control unit (control unit) for controlling the interface with the link layer, performing various controls during bus initialization, loop detection, and reconfiguration. A timer used when detecting a loop is also included. Details of the processing in the control unit will be described later.

Reference numeral 213 denotes a DS-Link system code decoder defined in the specification of the IEEE1394 interface.

Reference numeral 214 denotes an interface with the link layer, which is composed of various registers. It sends data received through this interface and data to be sent to other devices. It is also used when information on the existence or occurrence of a loop connection is transmitted to an upper layer.

FIG. 3 is a schematic diagram of a control procedure according to the first embodiment.
It shows the flow up to where the application layer in the interface system can operate.

In step 301, an initialization process from the execution of the bus reset to the start of the loop detection process is performed. Details will be described later with reference to FIG.

In step 302, a loop detection process is performed to determine whether there is a loop connection which is an irregular connection mode after the initialization, and to determine on the bus where the connection mode has been detected. Details will be described later with reference to FIG.

In step 303, it is determined whether a loop connection has been detected. If a loop connection is detected, the process proceeds to step 306. If it is determined that a normal bus can be configured without detecting the loop connection, the process proceeds to step 304.

In step 304, tree identification is performed in response to the determination that only a normal bus configuration has been performed.
For details of tree identification, refer to the explanation of the conventional example.

In step 305, self identification is performed in response to the tree identification. Specifically, by transmitting a self-ID packet including various nodes and receiving a self-ID packet from another node (device), information such as how many devices are connected on the bus is obtained. End the reset process.

In step 306, upon detecting the loop connection, the process branches depending on whether a normal bus configuration is possible by disabling any of the active ports of the own node. The branch itself is determined in the loop detection process of step 302. If the bus can be reconfigured, the process proceeds to step 307. If the bus cannot be reconfigured, the process proceeds to step 308.

In step 307, the bus is reconfigured in response to the determination that the bus can be reconfigured. Details of the bus reconfiguration will be described later with reference to FIG.

In step 308, the location where the loop connection is detected is notified to the user in response to the inability to reconfigure the bus. The means for notifying varies depending on the device, but may be a display on a display device, a result output to a medium such as paper, or a sound.

FIG. 4 is an initialization flow in the first embodiment.

This operation flow shows a flowchart for executing an initialization process. The operation flow starts when a bus reset signal is detected from a port to which a device is connected and when a bus reset is generated at its own node. The process ends when the initialization process is completed.

In step 401, upon receiving the start of the bus reset, it is detected whether or not there is an active port in the own node. If there is no active port, the process proceeds to step 402; otherwise, the process proceeds to step 404.

In step 402, since there is no active port, that is, since there is no device connected to this node, it is determined that the device is a stand-alone device, and the operation as a stand-alone device is started.

In step 403, the operation of the stand-alone device is started, and the process exits from the loop detection processing.

In step 404, it is determined whether or not a transmission request for causing a bus reset has been issued from an upper layer. Step 4 in the case of a bus reset transmission request
Go to step 05, otherwise go to step 408.

In step 405, upon receiving a bus reset transmission request, a bus reset signal is transmitted to all active ports.

In step 406, an idle signal is transmitted to all active ports that have transmitted the bus reset signal.

In step 407, it is determined whether or not idle signals have been received from all active ports. This routine is repeated until idle signals are received from all ports, and when all idle signals are received, the initialization routine ends.

In step 408, a bus reset signal is received in response to the fact that the bus reset is not a transmission request.

At step 409, it is checked whether any other active port exists. If there is, the process proceeds to step 409; otherwise, the initialization routine after the bus reset ends.

In step 410, a bus reset signal is transmitted to all active ports other than the port that has received the bus reset.

In step 411, following step 410, an idle signal is transmitted to all active ports that have transmitted the bus reset signal.

In step 412, it is determined whether or not idle signals have been received from all active ports. This routine is repeated until idle signals are received from all ports, and when all idle signals are received, the initialization routine ends.

The initialization routine is performed by taking the above steps.

FIGS. 5A to 5E are loop detection flows according to the first embodiment.

This operation flow shows a flowchart for executing the loop detection process. The operation starts when the initialization process is completed, and ends when the loop detection process is completed.

First, description will be made with reference to FIG.

In step 501, a timer having an arbitrary timer value is started to determine whether or not tree identification has been performed within a certain period of time. Here, it is assumed that the timer 1 is used.

In step 502, the number of active ports of the own node is confirmed. It is determined whether the number of active ports is one or more. If the number of active ports is two or more, the process proceeds to A. If the number of active ports is one, the process proceeds to step 503. The flow of the processing at the time of shifting to A will be described with reference to FIG.

In step 503, it is determined whether a Parent Notify signal has been received. The process proceeds to step 504 if received, and proceeds to step 505 if not received.

In step 504, upon receiving the Parent Notify signal, the node receives a Child Notify signal.
The signal is transmitted, and the process proceeds to step 520.

In step 505, upon receiving no Parent Notify signal, the own node transmits a Parent Notify signal to the node.

In step 506, it is determined whether or not the timer value counted by the timer 1 has been exceeded. If not exceeded, the process proceeds to step 509, and if a timeout occurs, the process proceeds to step 507.

In step 507, upon receiving the timeout of the timer 1, the partner node (device) recognizes that there is no response.

At step 508, since the connected node has recognized that there is no response, an error processing sequence is started. Specifically, the user is notified that the other node of the connection destination is not responding, or processing such as not adding the device to the tree configuration is performed.

At step 509, it is determined whether or not a Child Notify signal has been received. The process proceeds to step 520 if received, and proceeds to step 510 if not received.

In step 510, it is determined whether a Parent Notify signal has been received. If it has been received, the process proceeds to step 511; if it has not been received, the process proceeds to step 506.
Return to

In step 511, the timer 2 is started after the timer 1 is stopped. Here, the timer 2 is a timer for route conflict, and is for randomly selecting a time for determining a time until only two conflicting devices next transmit a Parent Notify signal.

At step 512, it is determined whether a Paent Notify signal has been received. The process proceeds to step 513 if received, and proceeds to step 515 if not received.

In step 513, upon receipt of the Parent Notify signal, a Child Notify signal is transmitted.

In step 514, the own node is determined to be the root device because the signal has been exchanged between the two competing devices.

In step 515, the parent node transmits a Parent Notify signal to the node in response to not receiving the Parent Notify signal.

At step 516, it is determined whether or not the timer value counted by the timer 2 is exceeded. If it does not exceed, it proceeds to step 517, and if it times out, it proceeds to step 518.

In step 517, it is determined whether a Child Notify signal has been received. If received, the process proceeds to step 520; otherwise, the process returns to step 516.

In step 518, upon receiving the timeout of the timer 2, the partner node (device) recognizes that there is no response.

At step 519, an error processing sequence is started when it is determined that the connection destination partner node has not responded. More specifically, it performs processing such as notifying the user that the destination node of the connection destination has not responded or not adding the device to the tree configuration.

In step 520, the end of the tree identification processing is confirmed.

The flow of the processing when the process shifts to A will be described with reference to FIG.

In step 521, the number of active ports is counted and the value is stored. Here, the value is stored in a parameter N temporarily.

At step 522, it is determined whether or not the number N of active ports is two. When there are two active ports, the process goes to step 523, and when there are three or more active ports, the process goes to C. The flow of the processing when shifting to C will be described with reference to FIG.

In step 523, it is determined whether or not the timer 1 has exceeded the counted timer value. If it does not exceed, it proceeds to step 524, and if it times out, it proceeds to step 527.

In step 524, it is determined whether a Parent Notify signal has been received. If it has been received, the process proceeds to step 525, and if it has not been received, step 523.
Return to

In step 525, upon receiving the Parent Notify signal, the child Notify
Send a signal.

At step 526, Pa is sent to the other port that is not the port that has received the Parent Notify signal.
Send rent Notify signal. Thereafter, the processing shifts to B, and the flow of the processing will be described with reference to FIG.

In step 527, the timer 3 is started in response to the timeout of the timer 1. Since there is a port in which a non-response state continues when the timer 1 times out, it is recognized that a loop has occurred as a first determination. If the detection is a normal loop connection detection, the process is terminated here. However, in the present invention, a process for accurately recognizing the location where the loop connection has occurred and for avoiding the loop is started. Timer 3 will force a non-responsive device
When the Parent Notify signal is sent, the Parent is sent from another port.
t A timer that counts the timeout period until the Notify signal returns.

At step 528, a Parent Notify signal is transmitted to any of the ports that have not responded.

At step 529, it is determined whether or not the timer value counted by the timer 3 is exceeded. If not exceeded, the process proceeds to step 532, and if a timeout occurs, the process proceeds to step 530.

In step 530, upon receiving the timeout of the timer 3, the partner node (device) recognizes that there is no response.

In step 531, an error processing sequence is started when the connected destination node recognizes that there is no response. More specifically, it performs processing such as notifying the user that the destination node of the connection destination has not responded or not adding the device to the tree configuration.

At step 532, it is determined whether a Child Notify signal has been received. If it has been received, the process proceeds to step 533. If it has not been received, the process returns to step 529 and the sequence during this period is repeated.

At step 533, it is determined whether or not the timer value counted by the timer 3 is exceeded. If not exceeded, the process proceeds to step 535. If the time-out occurs, the process proceeds to step 534.

In step 534, it is determined that the loop connection point is the node to which the Parent Notify signal has been forcibly transmitted from the own node or the connection destination node in response to the timeout of the timer 3. Also at that time Parent Not
It also determines that the bus cannot be reconfigured even if the port that transmitted the ify signal is disabled, and stores and saves such information.

In step 535, it is determined whether a Parent Notify signal has been received from a port different from the port to which the Parent Node has been forcibly transmitted. If it has been received, the process proceeds to step 536, and if it has not been received, the process returns to step 533 and the sequence during this period is repeated.

In step 536, the fact that a Parent Notify signal has been received from a port different from the port that has forcibly transmitted the Parent Notify signal from its own node causes a loop connection to occur between the two ports of its own node. It is determined that it exists in the bus connected to. It also determines that the bus can be reconfigured by disabling one of the ports of the own node, and stores and saves such information. The information stored and stored in step 534 and this step is used when disabling the active port when reconfiguring the bus and when notifying the user of the occurrence of the loop connection.

Referring to FIG. 5 (c), the flow of processing when shifting to "B" will be described.

At step 537, it is determined whether or not the timer 1 has exceeded the counted timer value. If it does not exceed, it proceeds to step 540, and if it times out, it proceeds to step 538.

At step 538, upon receiving the timeout of the timer 1, the partner node (device) recognizes that there is no response.

At step 539, since the other node of the connection destination recognizes that there is no response, an error processing sequence is started. Specifically, the user is notified that the other node of the connection destination is not responding, or processing such as not adding the device to the tree configuration is performed.

At step 540, it is determined whether a Child Notify signal has been received. The process proceeds to step 551 if received, and to step 541 if not received.

In step 541, it is determined whether a Parent Notify signal has been received. If it has been received, the process proceeds to step 542, and if it has not been received, step 537.
Return to

In step 542, the timer 2 is started after the timer 1 is stopped. Here, the timer 2 is a timer for route conflict, and it is previously that only two conflicting devices randomly select a time for determining a time until transmitting a Parent Notify signal. As described.

In step 543, it is determined whether a Parent Notify signal has been received. The process proceeds to step 544 if received, or to step 546 if not received.

At step 544, upon receipt of the Parent Notify signal, a Child Notify signal is transmitted.

At step 545, the own node is determined as the root device because the signal has been exchanged between the two competing devices.

In step 546, the parent node transmits a Parent Notify signal to the node in response to receiving no Parent Notify signal.

At step 547, it is determined whether or not the timer value counted by the timer 2 is exceeded. If not exceeded, the process proceeds to step 548, and if a timeout occurs, the process proceeds to step 549.

At step 548, it is determined whether a Child Notify signal has been received. If it has been received, the process proceeds to step 551. If it has not been received, the process returns to step 547.

In step 549, upon receiving the timeout of the timer 2, the partner node (device) recognizes that there is no response.

At step 550, an error processing sequence is started when the other node of the connection destination recognizes that there is no response. More specifically, it performs processing such as notifying the user that the destination node of the connection destination has not responded or not adding the device to the tree configuration.

In step 551, the end of the tree identification processing is recognized.

Referring to FIG. 5 (d), the flow of the processing when shifting to C will be described.

In step 552, it is determined whether or not the timer value counted by the timer 1 has been exceeded. If it does not exceed, it proceeds to step 553, and if it times out, it proceeds to step 558.

In step 553, it is determined whether a Parent Notify signal has been received. If it has been received, the process proceeds to step 554. If it has not been received, the process proceeds to step 552.
Return to

At step 554, upon receipt of the Parent Notify signal, a Child Notify signal is transmitted.

In step 555, 1 is subtracted from the value of the number of active ports N, and the value is stored in the parameter N.

At step 556, it is determined whether or not the value of the number N of active ports is one. If the number is 1, the process proceeds to step 557. In other cases, the process returns to step 552 until the number of active ports that have not received the Parent Notify signal becomes one, and the sequence during this period is repeated.

In step 557, a Parent Notify signal is transmitted to the remaining ports in response to the fact that the number of active ports has become one. After that, the process shifts to B, and the flow after shifting to B has been described with reference to FIG.

In step 558, the timer 3 is started in response to the timeout of the timer 1. Since there is a port in which a non-response state continues when the timer 1 times out, it is recognized that a loop has occurred as a first determination. The timer 3 is a timer that counts a timeout period until a Parent Notify signal returns from another port when a Parent Notify signal is forcibly transmitted to a device that does not respond.

At step 559, a Parent Notify signal is transmitted to any of the ports that have not responded. When the transmitted port is stored and the process of this step is performed again after a lapse of once from this process, a Parent Notify signal is transmitted to a port different from the port that has transmitted once.

At step 560, it is determined whether or not the timer value counted by the timer 3 is exceeded. If it does not exceed, it proceeds to step 563, and if it times out, it proceeds to step 561.

In step 561, upon receiving the timeout of the timer 3, the partner node (device) recognizes that there is no response.

At step 562, an error processing sequence is entered when the connected destination node recognizes that there is no response. Specifically, the process notifies the user that the other node of the connection destination has not responded, does not add the device to the tree configuration, and terminates the loop detection process.

In step 563, it is determined whether a Child Notify signal has been received. If it has been received, the process proceeds to step 564, and if it has not been received, the process returns to step 560 to repeat the sequence during this process.

In step 564, it is determined whether or not the timer value counted by the timer 3 is exceeded. If it does not exceed, it proceeds to step 565, and if it times out, it proceeds to step 568.

In step 565, it is determined whether a Parent Notify signal has been received from a port different from the port to which the Parent Node has been forcibly transmitted. If it has been received, the process proceeds to step 566. If it has not been received, the process returns to step 564 to repeat the sequence during this process.

In step 566, in response to the receipt of the Parent Notify signal from a port different from the port that has forcibly transmitted the Parent Notify signal from the own node, the location of the loop connection is between the two ports of the own node. It is determined that it exists in the bus connected to. At the same time, it is determined that the bus can be reconfigured by disabling the port from either of the own nodes, and the information is stored and saved.

In step 567, 2 is subtracted from the value of the number N of active ports to remove the two ports for which the current loop connection point has been determined, and the number of remaining ports is determined. If the number of remaining ports is two or more, the process returns to step 559 to repeat the processing sequence during this period. If not, that is, if there is only one port left, the process returns to step 503 in FIG. 5A, and the process for one active port is performed.

At step 568, it is determined that the occurrence of the loop connection is on the bus constituted by the node which has forcibly transmitted the Parent Notify signal from its own node or the connection destination node in response to the timeout of the timer 3. . At this time, it is also determined that the bus cannot be reconfigured even if the port that transmitted the Parent Notify signal is disabled.

At step 569, the content determined at step 568 is stored and held, the value of the number of active ports N is subtracted by 1, and the value is stored in the parameter N.

At step 570, the bus reset is executed while holding various information up to step 569.

In step 571, an initialization process is performed. The processing flow has already been described with reference to FIG.

At step 572, a timer 1 for deciding whether or not tree identification has been performed within a certain time is started.

At step 573, it is determined whether the value of the number N of active ports is 0 or not. If N is not 0,
In other words, if there is still a port whose status of the bus ahead of the port is not recognized by transmitting the Parent Notify signal, the flow returns to step 552 to repeat the sequence during this time. If N is 0, the process moves to E. E
The flow of processing when the process has shifted to will be described with reference to FIG.

Referring to FIG. 5 (e), the flow of processing when shifting to E will be described.

This figure shows a processing flow when it is determined that reconfiguration of the bus is impossible by disabling each of the plurality of active ports independently.

At step 574, it is determined whether or not the timer value counted by the timer 1 is exceeded. If a timeout has occurred, the process proceeds to step 575, and if not, the process returns to step 574 and repeats this step.

In step 575, the timer 3 is started in response to the timeout of the timer 1. Since there is a port in which a non-response state continues when the timer 1 times out, it is recognized that a loop has occurred as a first determination. The timer 3 is a timer that counts a timeout period until a Parent Notify signal returns from another port when a Parent Notify signal is forcibly transmitted to a device that does not respond.

At step 576, a plurality of ports for transmitting the Parent Notify signal are selected. If three ports A, B, and C are active, two ports are selected from these. Also remember the transmitted port,
When the process of this step is performed again after this process has been performed once, the Parent Notify signal is transmitted to a plurality of ports in a different combination from the port that has transmitted once. At the time of combination, it is possible to simultaneously transmit the Parent Notify signal up to a value smaller than the number N of active ports by one.

At step 577, a ParentNotify signal is transmitted to the plurality of ports selected at step 576.

At step 578, it is determined whether or not the timer value counted by the timer 3 is exceeded. If it does not exceed, it proceeds to step 581, and if it times out, it proceeds to step 579.

At step 579, the other node device recognizes that there is no response in response to the timeout of the timer 3.

At step 580, an error processing sequence is started because it is determined that the other node of the connection destination has not responded. Specifically, the process notifies the user that the other node of the connection destination has not responded, does not add the device to the tree configuration, and terminates the loop detection process.

At step 581, it is determined whether a Child Notify signal has been received. If it has been received, the process proceeds to step 582, and if it has not been received, the process returns to step 578 to repeat the sequence during this process.

At step 582, it is determined whether or not the timer value counted by the timer 3 is exceeded. If not exceeded, the process proceeds to step 583;
Select the port to send the ify signal.

In step 583, it is determined whether a Parent Notify signal has been received from a port different from the plurality of ports to which the Parent Notify signal has been forcibly transmitted from its own node. If it has been received, the process proceeds to step 584, and if it has not been received, the process returns to step 582 and the sequence during this period is repeated.

At step 584, in response to receiving a Parent Notify signal from a different port from the plurality of ports to which the Parent Node has forcibly transmitted the Parent Notify signal, information of a plurality of loop connection points is received. In addition, by judging that the bus reconfiguration is possible by disabling the multiple ports that have sent the ParentNotify signal from the own node forcibly, storing those information,
save.

At step 585, it is determined whether or not all possible combinations of the port combinations selected at step 576 have been selected. If all are confirmed, the loop detection processing process is terminated. If not, the process proceeds to step 586. Also, even if all combinations have not been confirmed, if a combination that can reconfigure the bus has been found, the loop detection processing process ends.

At step 586, a bus reset is executed while holding various information up to step 585.

At step 587, an initialization process is performed. The processing flow has already been described with reference to FIG.

At step 588, a timer 1 for deciding whether or not tree identification has been performed within a certain time is started. Thereafter, the processing is performed again from step 574 which is the first of this processing.

The loop detection process is performed by taking the above steps.

FIG. 6 is a bus reconfiguration flow according to the first embodiment.

In step 601, it is determined whether or not the user is notified of the detected loop connection point. This determination is made by determining in advance whether the user is to notify and entering a command to the device. The process proceeds to step 602 if notifying, or to step 603 if not.

At step 602, a notification of the loop connection point is made. The means of notification varies depending on the device, but in this embodiment, the notification is performed by displaying the information on a display device, which is one of the functions constituting the user interface.

In step 603, the active port is disabled based on the information stored in the previous processing.

In step 604, it is determined whether to notify the user of the port disable location. This determination is made by determining in advance whether the user is to notify and entering a command to the device.
The process proceeds to step 605 when notifying, or proceeds to step 606 when not.

In step 605, a port disable location is notified. There are various notification means, but in this embodiment, the notification is performed by displaying on a display device, which is one of functions constituting a user interface, or by using an LED or the like for displaying whether a port is active. .

In step 606, a bus reset is performed, and the bus reconfiguration process ends.

The bus reconfiguration process is performed by taking the above steps.

FIGS. 7A to 7G are schematic diagrams of a configuration including a loop connection in the first embodiment. (Hereinafter referred to as a first loop configuration diagram.) The flow from the detection of the loop connection to the reconfiguration of the bus will be described with reference to these diagrams.

FIG. 7A is a configuration diagram of a bus including a loop connection.

Here, reference numerals 701 to 708 denote nodes, and the node 701 is a device having the configuration of the present invention. Other devices are devices having one or a plurality of connection ports and conforming to the IEEE 1394 specification.

When a bus reset occurs after the connection as shown in the figure, a transition is made to the tree identification phase through the initialization process. First, nodes 705 and 70 that are Leaf
6, 707 and 708 transmit Parent Notify signals to the connected nodes. Parent Not
The Branch node that received the ify signal sets C to the port that received it.
Send hild Notify signal.

However, since a loop connection, which is an unacceptable connection mode other than the daisy chain connection and the branch connection, is established between the nodes 701, 702, 703, and 704, it is necessary to complete tree identification thereafter. As described in the prior art example, it is impossible to perform the operation.

From this state, the procedure in which the node 701 determines the location of the loop connection and reconfigures the bus will be described with reference to the following figures.

FIG. 7B shows a pickup of a node which has caused the loop connection shown in FIG. 7A.

As shown in the figure, nodes 701 to 70
Each node up to 4 is a branch node having two active ports. The node 701 is a device having the configuration of the present invention.

In FIG. 7C, the node 701 is the node 7
02, a Parent Notify signal is transmitted. This means that when the node 701 moves to the tree identification process, the timer is operated, and when a certain timer value is exceeded, the Parent N is activated from either of the two active ports.
Since the otify signal has not been received, it is determined that a loop connection has occurred somewhere, and active 2 is used to determine whether the connection point and the bus can be reconfigured.
A Parent Notify signal was forcibly transmitted to one of the ports. In this example, the Parent Notify signal is transmitted to the node 702, but may be transmitted to the other node 703.

In FIG. 7D, Pare from node 701
The node 702 that has received the nt Notify signal is the node 701
Sends a Child Notify signal to the Node 70
No. 2 transmits a Parent Notify signal to that port, that is, the node 704, because only one of the active ports that has not received the Parent Notify signal remains.

In FIG. 7 (e), in response to this, the node 7
Node 704 that has received the Parent Notify signal from
Transmits a Child Notify signal to the node 702, and transmits a Parent Notify signal to the node 703. Further, after transmitting the Child Notify signal to the node 704, the node 703 transmits a Parent Notify signal to the node 701.

Through the above process, the node 701 becomes the Parent
The port that sent the Notify signal and Parent Notify
A bus is configured by determining that a loop connection exists between ports that have received a signal and disabling one of two active ports (ports to which nodes 702 and 703 are connected). It also determines what can be done.

FIG. 7F is a configuration diagram of the bus when the node 701 disables the port connected to the node 702 based on the above determination. After the bus is reset and the bus is reconfigured after disabling, the nodes 701 and 702 are each set to Leaf, and the bus can be normally configured. Looking at FIG. 7A,
The nodes 703 and 704 have a bus configuration that is a route candidate.

FIG. 7G is a configuration diagram of the bus when the node 701 disables the port connected to the node 703 based on the same determination as in FIG. 7F. After the bus is reset and the bus is reconfigured after disabling, as a result, the nodes 701 and 703 become Leaf, respectively, so that the bus can be normally configured. In FIG. 7A, nodes 702, 703, and 704 have a bus configuration that is a route candidate.

When the above-described tree identification process is completed normally, a node number is assigned to each node, and a self-identification phase for enabling each other to perform data communication is started.

FIG. 8 shows a flow of loop detection of the first loop configuration example in the first embodiment described with reference to FIG. 7 described above.

In step 801, an initialization process is performed in response to the occurrence of a bus configuration trigger such as a bus reset. Refer to the description using FIG. 4 for details of this processing content.

At step 802, a timer having an arbitrary timer value (timer 1) is started to determine whether or not tree identification has been performed within a certain time.

In step 803, it is determined that a loop connection exists in the bus in response to the timeout of the timer 1, that is, the fact that tree identification has not been completed within a certain time.

At step 804, a Parent Notify signal is forcibly transmitted to the node 702, which is the connection destination node, in order to confirm the existence of the loop connection and determine whether the bus can be reconfigured.

In step 805, the node 702 that has received the Parent Notify signal
Send Notify signal.

In step 806, the node 702 transmits a Parent Notify signal to the node 704. Further, the node 704 transmits a Child Notify signal to the node 702.

In step 807, the node 704 transmits a Parent Notify signal to the node 703. Also, the node 703 transmits a Child Notify signal to the node 704.

In step 808, the node 703 transmits a Parent Notify signal to the node 701 (the device that has forcibly transmitted the Parent Notify signal).

At step 809, it is determined that a loop connection is formed on the bus by a device connected between two active ports.

At step 810, the user is notified of the occurrence of the loop. In the present embodiment, the node 70
The information is conveyed by displaying it on the display device 1.

At step 811, the port connected to the node 702 is disabled among the two active ports.

At step 812, the user is notified that the port has been disabled. In this embodiment, each port of the node 701 is provided with an LED that lights up when activated, and the LED is notified by stopping the lighting.

At step 813, a bus reset is generated.

In step 814, an initialization process is performed as in step 801.

At step 815, a tree identification process is performed. In the process before the bus reset, the loop configuration was detected during the execution of the tree identification process, so the bus configuration could not be continued.However, by disabling the ports, the tree identification process can be completed normally. it can.

In step 816, upon successful completion of the tree identification, a node number is assigned to each node, and a self-identification process for enabling each other to perform data communication is started. After the completion of the self-identification process, communication between the nodes can be performed.

FIGS. 9A and 9B are schematic diagrams of a bus configuration including a loop connection in the first embodiment. The flow from detection of a loop connection to determination of whether or not to reconfigure the bus will be described with reference to these drawings (hereinafter referred to as a second loop configuration diagram).

FIG. 9A is a configuration diagram of a bus including a loop connection.

Here, nodes 901 to 904 are nodes, and the node 901 is a device having the configuration of the present invention. Other devices are devices having one or a plurality of connection ports and conforming to the IEEE 1394 specification.

As shown, nodes 902, 903 and 9
A loop is formed between the lines 04.

In FIG. 9B, in the tree identification process, first, a timer is started with an arbitrary timer value (timer 1) in order to determine whether or not tree identification has been performed within a certain time. The node 901 which is a leaf having only one unique port transmits a Parent Notify signal to the node 902 to which the node is connected. Paren
The node 902 serving as a branch that has received the t Notify signal transmits a Child Notify signal to the node 901.

However, since the node 902 has received the Parent Notify signal from only one of the three active ports and cannot continue the subsequent processing, the timer 1 of the node 901 times out. That is, the tree identification process cannot be completed normally.

From this, the node 901 sets the Parent Not
It is determined that there is a device connected in a loop beyond the port that transmitted the ify signal, and that the bus cannot be reconfigured even if the active port is disabled. Since the bus cannot be reconfigured, the user is notified that a loop connection has occurred, and the process ends.

FIG. 10 shows a loop detection flow of the second loop configuration example in the first embodiment described with reference to FIG. 9 described above.

In step 1001, an initialization process is performed in response to the occurrence of a trigger for configuring the bus such as a bus reset. The details of this processing are shown in FIG.
See description using.

At step 1002, a timer having an arbitrary timer value (timer 1) is started to determine whether or not tree identification has been performed within a certain time.

In step 1003, the node 901 sends a Parent Notify to the node 902 that is the only connection destination.
Send a signal.

At step 1004, the node 902 which has received the Parent Notify signal
d Send a Notify signal.

At step 1005, since the subsequent processing cannot be continued due to the loop configuration, the timer 1 times out.

In step 1006, the device that has made a loop connection beyond the only active port that transmitted the Parent Notify signal in response to the timeout of timer 1, that is, the incomplete tree identification within a certain period of time, Determine that it exists. Further, it is determined that the bus cannot be reconfigured even if the active port is disabled.

In step 1007, the user is notified of the location where the loop has occurred. In this embodiment, the node 7
01 is displayed on the display device. It also indicates that disabling an active port prevents a normal bus configuration.

FIGS. 11A to 11D are schematic diagrams of a bus configuration including a loop connection in the first embodiment.
The flow from detection of connection to reconfiguration of the bus will be described with reference to these drawings (hereinafter referred to as a third loop configuration diagram).

FIG. 11A is a configuration diagram of a bus including a loop connection.

Here, nodes 1101 to 1107 are nodes, and the node 1101 is a device having the configuration of the present invention. IEEE with one or more connection ports
Each device conforms to the 1394 specification. 1108a-1
108c is a port of the node 1101.

As shown, nodes 1101, 1102, 1
Between nodes 104 and 1103 and nodes 1105 and 1106
And 1107, two loops are formed.
In this state, all nodes are in a branch state and the tree identification process cannot be performed normally.

In FIG. 11B, the node 1101 is connected to the node 1102 connected to the port 1108a.
Send Parent Notify signal. This is node 1101
Activates the timer at the time of the transition to the tree identification process, and from any of the three active ports when a certain timer value (timer 1) is exceeded.
Since no tify signal has been received, it is determined that a loop connection has occurred somewhere, and the connection point and one of the three active ports are used to determine whether the bus can be reconfigured. In response, a Parent Notify signal was forcibly transmitted. In this example, the Parent Notify signal is transmitted to the node 1102, but may be transmitted to another node 1103, 1105.
The timer is started with a timer value (timer 3) different from the above for determining whether a response to the Parent Notify signal transmitted before the transmission is made within the time.

[0266] In FIG.
The node 1102 that has received the Parent Notify signal transmits a Child Notify signal to the node 1101. Also, the node 1102 is the parent port for the node, ie, the node 1104, because the active port which has not received the Parent Notify signal has become the remaining one port.
Send Notify signal. Similarly, the node 11 receiving the ParentNotify signal from the node 1102
04 transmits a Child Notify signal to the node 1102, and transmits a Parent Notify signal to the node 1103. Further, the node 1103 is a child to the node 1104.
After transmitting the Notify signal, the parent 1101
Send Notify signal.

At this point, the node 1101 sets Parent Not
Port 1108a that forcibly transmitted the ify signal and Parent
It determines that a loop connection exists between the ports 1108b that have received the Notify signal, and also determines that a bus can be configured by disabling one of the two active ports.

Since there is another active port,
When the above determination is completed, a Parent Notify signal is transmitted to the port 1108c to which the node 1105 is connected. The branch node 1105 that has received the Parent Notify signal transmits a Child Notify signal to the node 1101.

However, since the node 1105 has received the Parent Notify signal from only one of the three active ports and cannot continue the subsequent processing, the timer times out. That is, the tree identification process cannot be completed normally. The processing flow in this case is the same as that described with reference to FIG.

[0270] Therefore, the node 1101
It is determined that there is a device connected in a loop beyond the port 1108c that has transmitted the otify signal, and even if this active port is disabled, the bus composed of the device connected to this device is enabled. Also judge that you cannot do it. However, by disabling the port 1108c, the node 1101
It is also determined that the bus can be reconfigured only by the devices of .about.1104.

FIG. 11D is a configuration diagram of the bus when the ports 1108a and 1108c are disabled based on the above determination. As a result of generating a bus reset after disabling and reconfiguring the bus, the nodes 1101 and 1102 become Leaf nodes, respectively, so that the bus can be normally configured. Even if the port 1108b is disabled instead of the port 1108a, a similar bus reconfiguration can be achieved. Node 110
Since nodes 5 to 1107 are not added to the configuration of the bus, depending on the definition of the user, it is possible to notify only the location of the loop connection without reconfiguring the bus between the nodes 1101 to 1104.

When the above tree identification process is completed,
Next, a node number is assigned to each node and self-identification for enabling each other to perform data communication is started.

FIG. 12 shows a loop detection flow of the third loop configuration example in the first embodiment described with reference to FIG. 11 described above.

In step 1201, the initialization process is performed in response to the occurrence of a trigger for configuring the bus such as a bus reset. The details of this processing are shown in FIG.
See description using.

In step 1202, a timer is started with an arbitrary timer value (timer 1) to determine whether or not tree identification has been performed within a certain time.

At step 1203, it is determined that a loop connection exists in the bus in response to the timeout of the timer 1, that is, the fact that tree identification has not been completed within a certain time.

In step 1204, a timer is started with a timer value (timer 3) different from the above timer value in order to determine whether there is a response to the Parent Notify signal transmitted in the next step.

At step 1205, a Parent Notify signal is forcibly transmitted to the node 1102, which is the connection destination node, in order to confirm the existence of the loop connection and determine whether the bus can be reconfigured.

In step 1206, the node 1102 that has received the Parent Notify signal
Send a Child Notify signal.

In step 1207, the node 1102 transmits a Parent Notify signal to the node 1104. In response, the node 1104 transmits a Child Notify signal to the node 1102.

In step 1208, the node 1104 sends a Parent Notify signal to the node 1103. In response, the node 1103 transmits a Child Notify signal to the node 1104.

In step 1209, the node 1103 transmits a Parent Notify signal to the node 1101 (the device that has forcibly transmitted the Parent Notify signal).

In step 1210, the node 1101 determines that a loop connection is formed by a device connected between the two active ports 1108a and 1108b. In addition, it is also determined that a bus can be configured by disabling one of the two active ports.

In step 1211, the remaining active port 1108 c is used to confirm the existence of the loop connection and determine whether the bus can be reconfigured.
Parent node is forcibly for (connection node is 1105)
Send ify signal.

At step 1212, the node 1105, which has received the Parent Notify signal,
Send a Child Notify signal.

In step 1213, the nodes 1105 to
Since the subsequent processing cannot be continued due to the loop configuration of 1107, the timer 3 of the node 1101 times out.

In step 1214, there is a device that is performing a loop connection beyond the active port 1108c that has transmitted the Parent Notify signal in response to the timeout of the timer 3, that is, the incomplete tree identification within a certain period of time. Judge to do. Further, it is determined that the bus cannot be reconfigured even if the active port is disabled. Also this port 110
By disabling 8c, nodes 1101 to 11
It is also determined that the bus can be reconfigured only by the device 04.

At step 1215, the user is notified of the occurrence of the loop connection. In this embodiment, the notification is made by displaying the information on the display device of the node 1101. If the user wants to reconfigure the bus among all the nodes connected to the bus, the process ends after notifying the location of the occurrence of the loop connection.

At step 1216, of the three active ports, ports 1108a and 1108c are disabled.

In step 1217, the user is notified that the port has been disabled. In this embodiment, each port of the node 1101 is provided with an LED that lights up when activated, and the LED is notified by stopping the lighting.

At step 1218, a bus reset is generated.

At step 1219, step 1201
The initialization process is performed in the same manner as described above.

At step 1220, a tree identification process is performed. Before the bus reset, the loop configuration was detected during the execution of the tree identification process, so that the bus configuration could not be continued. However, by disabling the ports, the tree identification process can be completed normally. The nodes constituting the bus are nodes 1101 to 1104
It is.

[0294] In step 1221, upon completion of the tree identification normally, a node number is assigned to each node, and a self-identification process is started for enabling data communication between the nodes. After the completion of the self-identification process, communication between the nodes can be performed.

FIGS. 13A to 13H are schematic diagrams of a bus configuration including a loop connection in the first embodiment.
The flow from detection of a loop connection to reconfiguration of the bus will be described with reference to these figures (hereinafter referred to as a fourth loop configuration diagram).

FIG. 13A is a configuration diagram of a bus including a loop connection.

Here, reference numerals 1301 to 1304 denote nodes, and the node 1301 is a device having the configuration of the present invention. IEEE with one or more connection ports
Each device conforms to the 1394 specification. 1305a-1
305c is a port of the node 1301.

As shown, between nodes 1301, 1302 and 1303, nodes 1301, 1303 and 13
A plurality of loops are formed in a complicated manner, for example, between nodes 04 and between nodes 1301, 1302, 1303 and 1304. In this state, all nodes are in a branch state and the tree identification process cannot be performed normally.

In FIG. 13B, the node 1301 is connected to the node 1304 connected to the port 1305a.
Send Parent Notify signal. This is node 1301
Activates the timer at the time of the transition to the tree identification process, and from any of the three active ports when a certain timer value (timer 1) is exceeded.
Since it has not received the tify signal, it is determined that a loop connection has occurred somewhere, and the connection point and one of the three active ports are used to determine whether the bus can be reconfigured. In response, a Parent Notify signal was forcibly transmitted. In this example, the Parent Notify signal is first transmitted to the node 1304, but may be transmitted to another connection node 1302 or 1303. A timer is started with a timer value (timer 3) different from the above to determine whether there is a response to the transmitted Parent Notify signal before transmission.

[0300] In FIG.
The node 1304 that has received the Parent Notify signal transmits a Child Notify signal to the node 1301. Also, the node 1304 has one or more active ports that have not received the Parent Notify signal, and the parent
Send a tify signal.

However, since the node 1303 has received the Parent Notify signal from only one of the three active ports and cannot continue the subsequent processing, the timer 3 times out. That is, the tree identification process cannot be completed normally.

From this, the node 1301 sets the Parent N
It determines that there is a device connected in a loop beyond the port 1305a that has transmitted the otify signal, and also determines that the bus cannot be reconfigured even if the active port is disabled. Then, the result determined as the content of the processing performed so far is stored.

In FIG. 13 (d), the node 1301 performs a bus reset after the above processing, and again forcibly executes Parent N
Transmit otify signal. The port to send this time is 130
5b. When the node 1301 shifts to the tree identification process, the timer is operated, and when a certain timer value (timer 1) is exceeded, no Parent Notify signal is received from any of the three active ports. Determines that a loop connection has occurred somewhere, and forces a Parent Notify signal to one of the three active ports to determine if the connection and the bus can be reconfigured Is the same as that for the port 1305a. Similarly, to determine whether there is a response to the Parent Notify signal transmitted before the transmission, the timer is started with another timer value (timer 3).

Thereafter, Parent Notif from node 1301
The node 1302 that has received the y signal transmits a Child Notify signal to the node 1301. Node 1302
Transmits the Parent Notify signal to that port, that is, to the node 1303, because only one of the active ports has not received the Parent Notify signal.

However, since the node 1303 has received the Parent Notify signal from only one of the three active ports and cannot continue the subsequent processing, the timer 3 times out. That is, the tree identification process cannot be completed normally.

From this, the node 1301 is connected to the port 1
As in the case of 305a, it is determined that there is a device connected in a loop beyond the port 1305b, and that the bus cannot be reconfigured even if the active port is disabled. Then, the result determined as the content of the processing performed so far is stored.

In FIG. 13 (e), the node 1301 resets the bus again after the above processing, and again forcibly performs Pare.
Sends nt Notify signal. The port to send this time is 1
305c. The same goes for activating a timer for determining whether there is a response to the transmitted Parent Notify signal before transmission.

Thereafter, the Parent Notif from the node 1301
The node 1303 that has received the y signal transmits a Child Notify signal to the node 1301. At this point, since the node 1303 has received the Parent Notify signal from only one of the three active ports, the subsequent processing cannot be continued, so that the timer 3 times out. That is, the tree identification process cannot be completed normally.

From this, the node 1301 is connected to the port 1
As in the case of ports 305a and 1305b, port 130
It is determined that there is a device connected in a loop before 5c, and that the bus cannot be reconfigured even if this active port is disabled. Then, the result determined as the content of the processing performed so far is stored.

In FIG. 13 (f), after the above processing, the node 1301 resets the bus again, and
Transmits otify signals to multiple ports. The ports to be transmitted this time are 1305a and 1305b. The same goes for activating a timer for determining whether there is a response to the transmitted Parent Notify signal before transmission. In this example, the Parent Notify signals are 1305a and 13
05b is transmitted to two ports, but this combination is different (for example, 1305b and 1305c)
But it doesn't matter.

In FIG. 13 (g), the
Nodes 1302 and 1 receiving Parent Notify signal
304 transmits a Child Notify signal to the node 1301. Nodes 1302 and 1304 are also Parent Not
Only one active port that has not received the ify signal has become Parent Notif.
Send the y signal. The destination node is 1303 and 1
A Child Notify signal is transmitted to 302 and 1304. At this point, since the number of active remaining ports of the node 1303 has also become one, the node 1303 transmits a Parent Notify signal to the node 1301.

By the processing up to this point, the node 1301 determines that a plurality of loop connections exist on the bus, and disables the active ports independently to disable the bus reconfiguration. Also judge. Further, it is also determined that the bus can be configured by disabling the two ports 1305a and 1305b forcibly transmitting the ParentNotify signal.

FIG. 13H is a configuration diagram of the bus when the ports 1305a and 1305b are disabled based on the above determination. As a result of performing bus reset after disabling the two ports and performing bus reconfiguration, the nodes 1301, 1302, and 1304 become Leaf nodes, respectively, and the bus configuration can be performed normally.

When the above tree identification process is completed,
Next, a node number is assigned to each node and self-identification for enabling each other to perform data communication is started.

FIG. 14 shows a loop detection flow of the fourth loop configuration example according to the first embodiment described with reference to FIG.

In step 1401, an initialization process is performed in response to the occurrence of a trigger for configuring the bus such as a bus reset. The details of this processing are shown in FIG.
See description using.

At step 1402, a timer is started with an arbitrary timer value (timer 1) in order to determine whether or not tree identification has been performed within a certain time.

At step 1403, it is determined that a loop connection exists in the bus in response to the timeout of the timer 1, that is, the fact that tree identification has not been completed within a certain time.

At step 1404, a timer is started with a timer value (timer 3) different from the above-mentioned timer to determine whether there is a response to the Parent Notify signal transmitted in the next step.

In step 1405, a Parent Notify signal is forcibly transmitted to the node 1304, which is the connection destination node, in order to confirm the existence of the loop connection and determine whether the bus can be reconfigured.

In step 1406, the node 1304 which has received the Parent Notify signal
Send a Child Notify signal.

At step 1407, the timer 3 times out because the subsequent processing cannot be continued due to the loop configuration.

In step 1408, there is a device that is performing a loop connection beyond the active port 1305a that has transmitted the Parent Notify signal in response to the timeout of the timer 3, that is, the incomplete tree identification within a certain period of time. Judge to do. Further, it is determined that the bus cannot be reconfigured even if the active port is disabled. Then, the processing contents and the judgment result are saved.

At step 1409, a bus reset is performed.

At step 1410, step 1401
The initialization process is performed in the same manner as described above.

At step 1411, step 1402
The timer 1 is started in the same manner as described above.

At step 1412, it is determined that a loop connection exists in the bus in response to the timeout of the timer 1, that is, the fact that the tree identification has not been completed within a certain time.

At step 1413, step 1404 is executed.
The timer 3 is started in the same manner as described above.

In step 1414, a Parent Notify signal is forcibly transmitted to the node 1302, which is the connection destination node, in order to confirm the existence of the loop connection and determine whether the bus can be reconfigured.

In step 1415, the node 1302 that has received the Parent Notify signal
Send a Child Notify signal.

At step 1416, the timer 3 times out because the subsequent processing cannot be continued due to the loop configuration.

In step 1417, step 1408
Parent Not in response to timer 3 timeout
It is determined that a device connected in a loop exists beyond the active port 1305b that has transmitted the ify signal. Further, it is determined that the bus cannot be reconfigured even if the active port is disabled. Then, the processing contents and the judgment result are saved.

In step 1418, a bus reset is performed.

At step 1419, step 1401
The initialization process is performed in the same manner as described above.

At step 1420, step 1402
The timer 1 is started in the same manner as described above.

At step 1421, it is determined that a loop connection exists in the bus in response to the timeout of the timer 1, that is, the fact that tree identification has not been completed within a certain time.

At step 1422, step 1404 is executed.
The timer 3 is started in the same manner as described above.

In step 1423, a Parent Notify signal is forcibly transmitted to the node 1303, which is the connection destination node, in order to confirm the existence of the loop connection and determine whether the bus can be reconfigured.

In step 1424, the node 1303 that has received the Parent Notify signal
Send a Child Notify signal.

At step 1425, since the subsequent processing cannot be continued due to the loop configuration, the timer 3 times out.

At step 1426, step 1408 is executed.
Parent Not in response to timer 3 timeout
It is determined that a device connected in a loop exists beyond the active port 1305b that has transmitted the ify signal. Further, it is determined that the bus cannot be reconfigured even if the active port is disabled. Then, the processing contents and the judgment result are saved.

At step 1427, a bus reset is performed.

In step 1428, step 1401
The initialization process is performed in the same manner as described above.

At step 1429, step 1402
The timer 1 is started in the same manner as described above.

In step 1430, it is determined that a loop connection exists in the bus in response to the timeout of the timer 1, that is, the fact that tree identification has not been completed within a certain time.

In step 1431, step 1404 is executed.
The timer 3 is started in the same manner as described above.

At step 1432, the port 1305a
Parent N for two ports, 1305b and 1305b
Send otify signal.

In step 1433, the nodes 1302 and 1304 that have received the Parent Notify signal
A Child Notify signal is transmitted to 301.

In step 1434, the node 1302 transmits a Parent Notify signal to the node 1303. In response to this, the node 1303 transmits a Child Notify signal to 1302.

In step 1435, the node 1304 sends a Parent Notify signal to the node 1303. In response to this, the node 1303 transmits a Child Notify signal to the node 1304.

In step 1436, the node 1303 receives the Parent Notify signal from the nodes 1302 and 1304 and sends a Parent
Send Notify signal.

In the step 1437, the step 1432
The port 130 that forcibly transmitted the Parent Notify signal at
It is determined that the bus can be reconfigured by disabling 5a and 1305b.

In step 1438, the user is notified of the location where the loop has occurred. In this embodiment, node 1
The information is conveyed by displaying it on the display device of 301.

At step 1439, ports 1305a and 1305b are disabled among the three active ports.

In step 1440, the user is notified that the port has been disabled. In this embodiment, each port of the node 1101 is provided with an LED that lights up when activated, and the LED is notified by stopping the lighting.

In step 1441, a bus reset is generated.

In step 1442, step 1401
The initialization process is performed in the same manner as described above.

In step 1443, a tree identification process is performed. During the initial bus configuration, the loop configuration was detected during the execution of this tree identification process, so the bus configuration could not be continued.However, disabling multiple ports successfully completed the tree identification process. Can be.

In step 1444, upon successful completion of tree identification, a node number is assigned to each node, and the process enters a self-identification process for enabling data communication between the nodes. After the completion of the self-identification process, communication between the nodes can be performed.

As described above, even when a plurality of loops exist, the loops can be avoided and a normal bus configuration can be formed.

As described above, according to the configuration of the present invention, the bus can be reconfigured by reliably detecting the loop connection and automatically avoiding the loop connection. In addition, it is possible to accurately notify the user of the location where the loop connection has occurred, including the case where reconfiguration is not possible.

[Second Embodiment] A second embodiment of the present invention will be described with reference to the drawings.

Since the present embodiment has the same configuration as that of the first embodiment except for a means for notifying the user, the description of the same portions will be omitted.

FIG. 15 is a block diagram showing a configuration in a device according to the second embodiment.

Reference numeral 1501 denotes a node (device body) having an interface conforming to the IEEE 1394 standard.
It is composed of blocks 1502, 1505 to 1513 described below. In this example, a printer device that outputs image data is assumed.

[0366] Reference numeral 1502 denotes a receptacle serving as a port (port) on the device main body side of the IEEE1394 interface. Here, cables for connecting other various devices are inserted.

Reference numeral 1503 denotes a plug of the IEEE1394 interface cable. This part is connected to the ports of various devices.

Reference numeral 1504 denotes an IEEE1394 interface cable. In this cable, two sets of twisted pair cables (one is a signal line called A and the other is a signal line called B) and one
Six cables, including the power supply pair cables, are crossed.

[0369] Reference numeral 1505 denotes 100 Mb conforming to IEEE1394.
Various hardware logics (multi-port of twisted pair interface, interface to link layer IC, synchronization and reconfiguration of packet data, bit-level arbitration, And an initialization logic, a timer, etc., which are the gist of the present invention). See FIG. 2 for details of functions and configurations.

[0370] Reference numeral 1506 denotes a link layer controller conforming to IEEE 1394, which is constituted by various hardware logics.

[0371] Reference numeral 1507 denotes various controls of the device and
It is a CPU that implements the functions of the transaction layer, node controller, and application layer of the IEEE1394 interface.

[0372] Reference numeral 1508 denotes a RAM for storing commands and data necessary for the CPU 1507 to perform various processes. It is also used for storing transfer data via the IEEE1394 interface and for temporarily storing image data output by a printer.

[0373] Reference numeral 1509 denotes a ROM storing control information of the present device. It is also possible to update the control information later by using a flash memory or the like.

An ASIC 1510 performs mechanical control of the device and various image processing. It is a dedicated hardware logic for performing various processes such as controlling the printer head at the time of printing image data and expanding transmitted image data.

Reference numeral 1511 denotes a printer. Mechanical mechanism,
It is composed of an ink tank, an ink head and the like. In this example, an ink jet printer is assumed, but a printer configuration using various methods such as a thermal transfer method and an electrophotographic method can be considered.

[0376] Reference numeral 1512 denotes a user interface for notifying a user of a status and receiving a command input from the user. It comprises a display unit for notification and an operation unit for receiving input.

[0377] Reference numeral 1513 denotes a system bus. In addition to the blocks 1506 to 1512 shown in the figure, blocks not shown also hang on this bus, and high-speed data transfer between the blocks can be performed.

In this configuration, as in the first embodiment, not only can the display portion of the user interface 1512 be notified of the occurrence of the loop connection, but also the loop function for the medium (generally paper) can be performed by the printer function of the device. It is also possible to print out the location where the connection has occurred to notify it. In this case, it is possible not only to print out the location of occurrence with textual information but also to print the tree structure. The generation of the print data indicating the location where the loop connection occurs is performed by the CPU in the printer.

As described above, according to the configuration of the present invention, the bus can be reconfigured by reliably detecting the loop connection and automatically avoiding the loop connection. In addition, it is possible to accurately notify the user of the location where the loop connection has occurred, including the case where reconfiguration is not possible. In addition, since this device has a printer function, it is possible to notify the user of the occurrence of a loop connection not only by outputting to a display device but also by outputting to a medium such as paper, so that the device is more intuitive than the notification using a display device And can convey more information.

[Third Embodiment] A third embodiment of the present invention will be described with reference to the drawings.

Since the present embodiment has the same configuration as that of the first embodiment except for a means for notifying the user, the description of the same portions will be omitted.

FIG. 16 is a block diagram showing a configuration in a device according to the third embodiment.

Reference numeral 1601 denotes a node (device body) having an interface conforming to the IEEE1394 standard.
It is composed of blocks 1602, 1605 to 1615 described below. In this example, read moving image data,
A digital video camera that performs storage and output is assumed.

Reference numeral 1602 denotes a receptacle serving as a port (port) on the device main body side of the IEEE1394 interface. Here, cables for connecting other various devices are inserted.

Reference numeral 1603 denotes a plug of the IEEE1394 interface cable. This part is connected to the ports of various devices.

Reference numeral 1604 denotes an IEEE1394 interface cable. In this cable, two sets of twisted pair cables (one is a signal line called A and the other is a signal line called B) and one
Six cables, including the power supply pair cables, are crossed.

1605 is 100 Mb conforming to IEEE1394.
Various hardware logics (multi-port of twisted pair interface, interface to link layer IC, synchronization and reconfiguration of packet data, bit-level arbitration, And an initialization logic, a timer, etc., which are the gist of the present invention). See FIG. 2 for details of functions and configurations.

[0388] Reference numeral 1606 denotes a link layer controller conforming to IEEE 1394, which is constituted by various hardware logics.

Reference numeral 1607 denotes various controls of the present device and
It is a CPU that implements the functions of the transaction layer, node controller, and application layer of the IEEE1394 interface.

[0390] Reference numeral 1608 denotes a RAM for storing commands and data necessary for the CPU 1607 to perform various processes. It is also used for temporary storage when transferring moving image data by the IEEE1394 interface and writing read image data to a DV cassette.

[0390] Reference numeral 1609 denotes a ROM in which control information of the present device is stored. It is also possible to update the control information later by using a flash memory or the like.

Reference numeral 1610 denotes an ASIC for performing mechanical control of the device and various image processing. It is a dedicated hardware logic for performing various processes such as various controls of a video camera unit such as lens autofocus, control of a magnetic head when saving moving image data, and compression processing of image data to be transmitted.

Reference numeral 1611 denotes a user interface for notifying a user of a status and receiving a command input from the user. It comprises a display unit for notification and an operation unit for receiving input.

[0394] Reference numeral 1612 denotes an image pickup unit for reading moving image data. It is composed of various correction circuits in addition to the lens.

[0395] Reference numeral 1613 denotes a recording unit for reading and storing the read moving image data. Recording is performed on a DV specification cassette.

[0396] Reference numeral 1614 denotes a speaker that reproduces an audio signal recorded by a microphone (not shown).

Reference numeral 1615 denotes a system bus. In addition to the illustrated blocks 1606 to 1614, unillustrated blocks also hang on this bus, and high-speed data transfer can be performed between the blocks.

In this configuration, as in the first embodiment, not only can the display portion of the user interface 1611 be notified of the occurrence of the loop connection, but also the user can be notified by voice using the speaker 1614 of the device. It is.

As described above, according to the configuration of the present invention, the bus can be reconfigured by reliably detecting the loop connection and automatically avoiding the loop connection. In addition, it is possible to accurately notify the user of the location where the loop connection has occurred, including the case where reconfiguration is not possible. Further, since this device has a speaker, the user can be notified of the occurrence of the loop connection not only by output to the display device but also by audio output, thereby calling for more attention.

[0400]

[Other Embodiments] The present invention can be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), and can be applied to a single device (for example, Copy machine, facsimile machine, etc.).

Further, an object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or an apparatus, and to provide a computer (or CPU) of the system or the apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

Examples of a storage medium for supplying the program code include a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, and CD.
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the program code is read based on the instruction of the program code. It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to the above-described flowcharts. Each module shown will be stored in a storage medium. That is, at least “bus configuration module 2101”, “loop detection module 2102” and “signal generation module 2103”
"Signal receiving module 2104""Decision module 21"
05, “disable module 2106”, and “system reconfiguration start module 2107” may be stored in the storage medium.

[0407]

As described above, according to the present invention, the following effects can be obtained.

[0408] Reliable loop detection is performed and the loop connection is automatically avoided to reconfigure the bus. In addition, it is possible to accurately notify the user of the location where the loop connection has occurred, including the case where reconfiguration is not possible.

That is, the reliability of the configuration of the bus is significantly improved by reliably detecting the loop connection mode.

[0410] Further, it is possible to accurately inform the user of the location of the occurrence of the loop connection by display or the like.

[0411] Even if a device having this function does not form a loop connection, if a loop connection exists on the serial bus, it is possible to recognize the location where the loop connection has occurred.

The user can automatically avoid the loop connection and construct a normal bus without taking the trouble of disconnecting the cable. In other words, the convenience of the user is dramatically improved.

[0413] Even if two or more loop connections occur on the serial bus, the existence thereof can be detected.

[0414]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration in a device according to a first embodiment.

FIG. 2 is a configuration diagram of a PHY block according to the first embodiment.

FIG. 3 is a flow (initialization, loop detection, bus reconfiguration) showing an outline of a control procedure in the first embodiment.

FIG. 4 is an initialization flow in the first embodiment.

FIG. 5A is a loop detection flow in the first embodiment.

FIG. 5B is a loop detection flow in the first embodiment.

FIG. 5C is a loop detection flow in the first embodiment.

FIG. 5D is a loop detection flow in the first embodiment.

FIG. 5E is a loop detection flow in the first embodiment.

FIG. 6 is a bus reconfiguration flow in the first embodiment.

FIG. 7A is a first loop configuration diagram in the first embodiment.

FIG. 7B is a first loop configuration diagram in the first embodiment.

FIG. 7C is a first loop configuration diagram in the first embodiment.

FIG. 7D is a first loop configuration diagram in the first embodiment.

FIG. 7E is a first loop configuration diagram in the first embodiment.

FIG. 7F is a first loop configuration diagram in the first embodiment.

FIG. 7G is a first loop configuration diagram in the first embodiment.

FIG. 8 is a loop detection flow in the case of a first loop configuration in the first embodiment.

FIG. 9A is a diagram illustrating a second loop configuration according to the first embodiment.

FIG. 9B is a second loop configuration diagram in the first embodiment.

FIG. 10 is a loop detection flow in the case of a second loop configuration in the first embodiment.

FIG. 11A is a third loop configuration diagram in the first embodiment.

FIG. 11B is a third loop configuration diagram in the first embodiment.

FIG. 11C is a third loop configuration diagram in the first embodiment.

FIG. 11D is a third loop configuration diagram in the first embodiment.

FIG. 12 is a processing flow in the case of a third loop configuration in the first embodiment.

FIG. 13A is a fourth loop configuration diagram according to the first embodiment.

FIG. 13B is a fourth loop configuration diagram according to the first embodiment.

FIG. 13C is a fourth loop configuration diagram according to the first embodiment.

FIG. 13D is a fourth loop configuration diagram according to the first embodiment.

FIG. 13E is a fourth loop configuration diagram according to the first embodiment.

FIG. 13F is a fourth loop configuration diagram according to the first embodiment.

FIG. 13G is a fourth loop configuration diagram according to the first embodiment.

FIG. 13H is a fourth loop configuration diagram according to the first embodiment.

FIG. 14A is a processing flow in the case of a fourth loop configuration in the first embodiment.

FIG. 14B is a processing flow in the case of a fourth loop configuration in the first embodiment.

FIG. 15 is a block diagram showing a configuration in a device according to the second embodiment.

FIG. 16 is a block diagram showing a configuration in a device according to the third embodiment.

FIG. 17 is a configuration diagram of a bus in a conventional example.

FIG. 18 is a diagram showing tree identification (1) in a conventional example.

FIG. 19 is a diagram showing tree identification (2) in a conventional example.

FIG. 20 is a configuration diagram of a bus including a loop connection in a conventional example.

FIG. 21 is a diagram showing a memory map of a recording medium.

[Explanation of symbols]

 101 node (device main body) 102 receptacle 103 plug 104 cable 105 PHY 106 LINK 107 CPU 108 RAM 109 ROM (flash ROM) 110 ASIC 111 scanner 112 UI (user interface) 113 system bus

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04L 12/28 H04L 11/00 310D

Claims (30)

[Claims] 1. A configuration means for detecting a connection or disconnection of a device and configuring a bus, a loop detection means for judging a connection mode of a device on an interface system and detecting the presence of a loop-connected device, One or more ports serving as connection ports with other devices, signal generating means for forcibly generating a Parent Notify signal from the port, signal receiving means for receiving a Parent Notify signal from the port, Judging means for judging the occurrence of a loop connection from the transmission and reception states of the signal, disabling means for disabling an active port based on the judgment result of the judging means, disabling of the port by the disabling means And system reconfiguration starting means for starting the bus configuration means again later. Serial bus interface device. 2. The method according to claim 2, wherein the serial bus interface is an IE.
2. The device according to claim 1, which is compliant with EE1394.
2. A serial bus interface device according to claim 1. 3. The serial communication device according to claim 1, wherein the loop detection unit recognizes that a device connected in a loop exists on the bus when the count value of the timer exceeds an arbitrary timer value. Bus interface device. 4. The serial bus interface device according to claim 1, further comprising means for notifying a user of a loop detection result by said loop detecting means. 5. The serial bus interface device according to claim 4, wherein the means for notifying a user of a loop detection result by the loop detection means is based on a display on a display device. 6. When the serial bus interface device is a printer and a device capable of printing on a medium, a loop detection result by the loop detecting means is printed out on a medium to notify a user. The serial bus interface device according to claim 4, wherein 7. The serial bus interface device according to claim 4, wherein the means for notifying the user of the result of the loop detection by the loop detection means is based on voice transmission. 8. The serial bus interface device according to claim 1, wherein when there are a plurality of ports, loop detection can be performed on each of the plurality of ports. 9. The system reconfiguration starting means disables a port when the determination means determines that the serial bus interface device is present on a bus forming a loop on the serial bus interface system. 5. The serial bus interface device according to claim 1, wherein a system reconfiguration is executed, and when it is determined that the loop connection is not present, the display unit notifies the user only of the presence of the loop connection. . 10. The method according to claim 1, wherein when a plurality of ports are active, a Parent Notify signal is generated for a port that has not received the Parent Notify signal, and the Parent Notify signal is generated at a port other than the port that transmitted the Parent Notify signal. 2. The serial bus interface device according to claim 1, wherein upon reception, it is determined that a loop exists on a bus connected between the ports. 11. The apparatus according to claim 1, wherein the signal generation unit generates a Parent Notify signal for a port that has not received a Parent Notify signal when a plurality of ports are active.
When a Parent Notify signal cannot be received from any other port, a Parent Notify signal is generated for another port that has not received the Parent Notify signal, and an operation for confirming the existence of a loop is performed. The serial bus interface device according to claim 1. 12. When a Parent Notify signal is generated for a port that has not received a Parent Notify signal when an active port is present, the determination means starts a timer with an arbitrary timer value, If a Parent Notify signal cannot be received from any other port when the timer value is exceeded, it is determined that a loop exists on a bus formed between devices connected to the port. 2. The serial bus interface device according to 1. 13. An arbitrary timer value used in the loop detecting means and an arbitrary timer value used in the judging means are set to different values, and the activation timings of the loop detecting means and the judging means are set. The serial bus interface device according to claim 1, wherein the serial bus interface device is changed. 14. The serial bus interface according to claim 1, further comprising notifying means for notifying a user which port has been disabled when a port has been disabled by said disable means. device. 15. A bus configuration step for detecting additional connection or disconnection of a device to configure a bus, a loop detection step for detecting the presence of a loop-connected device on an interface system at the time of a bus configuration, and a loop detection step. Pare forcibly from the port that is the connection port of
a signal generating step of generating an nt Notify signal, a signal receiving step of receiving a Parent Notify signal from the port, a determining step of determining a location of a loop connection from the transmission and reception status of the signal, and a determination of the determining step A serial bus comprising: a disable step of disabling an active port based on a result; and a system reconfiguration start step of restarting the bus configuration step after disabling the port by the disable step. Interface bus configuration method. 16. The serial detecting method according to claim 15, wherein in the loop detecting step, when a count value by a timer exceeds an arbitrary timer value, it is recognized that a device connected in a loop exists on a bus. Bus configuration method of the bus interface. 17. The bus configuration method according to claim 15, further comprising a step of notifying a user of a loop detection result in the loop detection step. 18. The bus configuration method according to claim 17, wherein in the step of notifying the user, a result of the loop detection by the loop detecting step is notified by a display. 19. When the device constituting the serial bus interface bus is a device capable of printing on a medium such as a printer, a user is notified of a loop detection result in the loop detecting step by a method of printing out the medium. 18. The bus configuration method for a serial bus interface according to claim 17, wherein: 20. The bus configuration method according to claim 17, wherein the step of notifying the user notifies the result of the loop detection by the loop detecting step by voice transmission. 21. The method according to claim 15, wherein the loop detecting step is capable of detecting a plurality of loops. 22. If the determination step determines that the serial bus interface device is present on a bus forming a loop on the serial bus interface system, the system reconfiguration start step disables a port. 16. The serial bus interface according to claim 15, wherein performing the system reconfiguration, and when it is determined that the loop connection is not present, the step of notifying the user only notifies the user of the existence of the loop connection. Bus configuration method. 23. The method according to claim 23, wherein when a plurality of ports are active, a Parent Notify signal is generated for a port that has not received the Parent Notify signal, and the Parent Notify signal is generated at a port other than the port that transmitted the Parent Notify signal. 16. The bus configuration method according to claim 15, wherein upon reception, it is determined that a loop exists on a bus connected between the ports. 24. The method according to claim 24, wherein the signal generating step includes generating a Parent Notify signal for a port that has not received the Parent Notify signal when the plurality of ports are active.
When a Parent Notify signal cannot be received from any other port, a Parent Notify signal is generated for another port that has not received the Parent Notify signal, and an operation for confirming the existence of a loop is performed. A bus configuration method for a serial bus interface according to claim 15. 25. The method according to claim 23, wherein the determining step starts a timer with an arbitrary timer value when a Parent Notify signal is generated for a port that has not received the Parent Notify signal when an active port exists. If a Parent Notify signal cannot be received from any other port when the timer value is exceeded, it is determined that a loop exists on a bus formed between devices connected to the port. 16. A bus configuration method for a serial bus interface according to claim 15. 26. An arbitrary timer value used in the loop detection step and an arbitrary timer value used in the determination step are set to different values, and the activation timings of the loop detection step and the determination step are set. The bus configuration method for a serial bus interface according to claim 15, wherein the bus configuration is changed. 27. The serial bus interface according to claim 15, further comprising a notifying step of notifying a user which port is disabled when the port is disabled by the disabling step. Bus configuration method. 28. A bus configuration step of detecting the additional connection or disconnection of a device to configure a bus, a loop detection step of detecting the presence of a loop-connected device on an interface system when the bus is configured, and a loop detection step. Pare forcibly from the port that is the connection port of
a signal generating step of generating an nt Notify signal; a signal receiving step of receiving a Parent Notify signal from the port; a determining step of determining a location of occurrence of a loop connection from the transmission and reception states of the signal; and a determination of the determining step A disabling step of disabling an active port based on the result; and a system reconfiguration starting step of re-starting the bus configuration step after disabling the port by the disabling step. A recording medium characterized by being recorded. 29. A serial bus interface system comprising a plurality of devices connected by a serial bus interface device, wherein the serial bus interface device according to claim 1 is used as the serial bus interface device. Serial bus interface system. 30. The serial bus interface system according to claim 29, wherein the device connected by the serial bus interface device has a printer function.