JP2008117289A - Data communication system, unit and data communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data communication system, a unit and a data communication method, executing data communication based on the USB specification between an information processor and a peripheral device. <P>SOLUTION: This data communication system 10 comprises a main unit 20 and at least one subunit 50, and executes the data communication with the external device by the USB protocol. The main unit has: a function provision means 40 for providing a function as a USB device; and a data flow control means 46 controlling data transmission with the subunit 50. The subunit 50 has: a USB device provision means 80; a bus interface provision means 82 executing signal transmission with the external device; and a data exchange means with the main unit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to universal serial bus (USB) technology, and more particularly, to a data communication system, a unit, and a data communication method for executing data communication conforming to the USB standard between an information processing apparatus and a peripheral device. .

  Currently, many information processing apparatuses such as personal computers (PCs) are typically equipped with a universal serial bus (USB) interface as an interface for connecting peripheral devices. In recent years, a wireless USB (WUSB) standard in which a wireless communication technology is applied to a USB physical layer has also been proposed.

  In the USB protocol, communication between a USB host and a USB device is described using a three-layer model. That is, the USB system includes (1) a USB bus interface layer for controlling a wired or wireless physical transmission signal between the host and the device, and (2) logical data in communication between the USB host and the USB device. It comprises a USB device layer that provides and manages transmission endpoints, and (3) client software executed on the USB host, and a function layer that provides logical communication with USB device functions.

  Logical communication between a USB host such as a PC and a USB device such as a peripheral device between a communication buffer on the USB host side and an endpoint on the USB device side (also a communication buffer and located on the second layer) In the third layer, the client software on the USB host side and the function on the USB device side are logically connected via a pipe bundle (which constitutes an interface) composed of at least one pipe. Various device functions of peripheral devices are provided to the USB host.

  The USB host is connected to a plurality of USB devices in a one-to-many manner via a hub, and data transfer on the bus is controlled by USB system software corresponding to the second layer on the USB host. Since the centralized control format by the USB host is adopted, the USB device is controlled by a single USB host and cannot be shared simultaneously by a plurality of USB hosts.

  For example, Japanese Patent Application Laid-Open No. 2004-295407 (Patent Document 1) discloses a plurality of host PCs connected to an upstream connector because a USB device can be shared among a plurality of USB hosts. A USB hub device is disclosed that includes a connection state monitoring CPU that monitors the state of the device based on priority, and a selector that switches the host connected to the downstream connector by the connection state monitoring CPU.

However, in the above-described conventional technology, the connection state of the upstream port is monitored, and it is determined whether the power of the host device is off (or not connected) or is in the suspended state. The electrical connection is switched, and the USB device is not logically recognized simultaneously by a plurality of USB hosts, and is not sufficient in terms of convenience.
JP 2004-295407 A

  The present invention has been made in view of the above prior art, and is connected to and recognized by a plurality of USB hosts, executes a process in response to a request from a plurality of USB hosts, and has a high degree of freedom between USB devices. It is an object to provide a data communication system, a unit, and a data communication method.

  Another object of the present invention is to provide a data communication system, a unit, and a data communication method that can function as a USB repeater with a simple operation and enable highly flexible data flow control between USB devices. The purpose is to provide.

  In order to solve the above-described problems, the present invention provides a USB device providing unit and a wireless communication unit that provide a logical communication path between a main unit including a function providing unit that provides a function as a USB host or USB device, and an external device. Alternatively, a configuration called a data communication system including a subunit including a USB bus interface providing unit that performs substantial communication with a wired external device is adopted. The main unit is electrically and logically connected to at least one subunit, and the external device connected to each subunit is connected via a logical communication path provided by the USB device providing means of each subunit. Connected. The main unit identifies the subunit, and data transmission between the main unit and the subunit or between the subunits via the main unit is controlled by the data flow control means.

  With the above configuration, for example, a main unit having a device function is connected to an external device as a plurality of USB hosts via a subunit, and can be logically recognized simultaneously by each external device. . The main unit identifies the transmission source of the request by identifying the subunit, and the main unit executes processing in response to the request from each subunit, allowing device functions to be shared by multiple external devices. To do. In addition, the configuration for controlling the data flow between the main unit and the plurality of subunits makes it possible to function as a repeater that provides various connection modes between external devices connected to the subunits. .

That is, according to the present invention, there is provided a data communication system that includes a main unit and at least one subunit, and executes data communication with an external device using a USB protocol.
The main unit is
A function providing means for providing a function as a USB device; and a data flow control means for identifying the subunit and controlling data transmission with the subunit;
The subunit is
A bus interface providing means for executing signal transmission with the external device, a USB device providing means for receiving arbitration by the data flow control means, and a data exchanging means with the main unit.
A data communication system is provided.

  The USB device providing means provides an endpoint for establishing a logical communication path with the external device as a USB host, and the data exchange means exchanges data between the endpoint and the main unit. Can be executed. The data flow control means identifies the data transmission source or transmission destination subunit, and controls the data transmission with the subunit in response to a processing request or an external command from the external device. be able to.

According to the present invention, there is provided a main unit including a slot for mounting at least one subunit, and capable of executing data communication with an external device using a USB protocol,
The main unit is
A main unit comprising function providing means for providing a function as a USB device, and data flow control means for controlling data transmission with the subunit in response to a processing request or an external command from the external device Is provided.

  The main unit may be arranged with a plurality of the slots apart from each other.

Furthermore, according to the present invention,
A subunit that is attached to a main unit for providing a function as a USB device, and that can execute data communication with an external device using a USB protocol,
The subunit is
A subunit comprising a bus interface providing means for executing signal transmission with the external device, a USB device providing means, and a data exchanging means with the main unit is provided.

  The USB device providing means provides an endpoint for establishing a logical communication path with the external device as a USB host, and the data exchange means exchanges data between the endpoint and the main unit. Can be executed. The subunit may include data flow control means for controlling data transmission with the main unit in response to an external command. Furthermore, the subunit may comprise a directional antenna. The subunit may include instruction means for receiving an external command for switching data flow.

According to the invention,
A data communication method using a USB protocol between a data communication system including a main unit and at least one subunit and an external device,
The data communication method includes:
Establishing a logical communication path between the subunit and the external device;
Transferring data according to the USB protocol via the logical communication path;
Performing a data exchange between the subunit and the main unit so that the subunit can be identified.

The data communication method includes executing a request process in response to the data;
Controlling the exchange of data in response to the request processing or an external command.

  The present invention will be described below with reference to embodiments shown in the drawings, but the present invention is not limited to the embodiments shown in the drawings.

  FIG. 1 is a block diagram illustrating an embodiment of a hardware configuration of a data communication system 10 including a main unit and subunits. FIG. 1 shows an embodiment in which the data communication system 10 functions as an image forming apparatus. The data communication system 10 includes a main unit 20, a subunit A 50a, and a subunit B 50b. The main unit 20 includes a CPU 22, a ROM 24, and a memory 26, which are interconnected by an internal bus 38 and execute a job instructed by a user. The CPU 22 reads out the processing program from the storage device 32 such as the ROM 24, NVRAM, EEPROM, EPROM, or hard disk to the memory 26, expands it, and executes processing for the commanded job.

  The main unit 20 includes an operation unit 28 and a display unit 30. The operation unit 28 and the display unit 30 are each connected to the CPU 22 via an internal bus 38 and provide a user interface. The main unit 20 further includes an interface (I / F) 36 connected to the internal bus 38, and is connected to the subunit 50 connected via the connection bus 12 configured as a serial bus and a parallel bus. I / O is managed. The printer 34 sends a request from the USB host (hereinafter referred to as an external device that is a host on the USB protocol as a USB host regardless of wired / wireless protocol) via the interface 36 to communicate with the subunit 50. It receives the data, executes device processing as an image forming apparatus such as print processing under the control of the CPU 22, and provides a device function to the communicating USB host. That is, the main unit 20 provides software and hardware processing for executing device functions corresponding to the function layer in the WUSB protocol.

The subunit A 50a includes a controller 52, a memory 54, and a wireless communication unit 56, which are connected by an internal bus, respectively, and a USB host A and a wireless USB based on a UWB (Ultra Wide Band) communication protocol. A communication link that conforms to the protocol is established. The wireless communication unit 56 is connected to the antenna 64 and includes a physical layer (UWB) including a UWB high frequency circuit.
RF PHY) 62 and a physical layer (UWB BB PHY) 60 including a UWBBaseBand circuit. The UWB-BB physical layer 60 mainly performs signal modulation / demodulation processing, and the UWB-RF physical layer 62 performs waveform shaping of a high-frequency signal.
A physical layer is configured in accordance with a communication protocol conforming to IEEE 802.15TG3a such as Orthogonal Frequency Division Multiplexing (DS) or DS-UWB (Direct Sequence UWB).

  The subunit A 50a includes an NVRAM 58. The NVRAM 58 stores a connection context for performing wireless USB communication with a USB host, identifies a connection destination USB host, and performs encryption / decryption processing of communication data. Used for. The memory 54 of the subunit A 50a buffers transmission data from the connected USB host A or the main unit 20, and provides an endpoint in the USB protocol. The memory 54 stores various setting information such as a device address assigned from the USB host A and a unit identification value assigned from the main unit 20.

  The controller 52 includes a MAC (medium access control) layer 66 and performs control corresponding to the data link layer of the WUSB protocol with the connection destination USB host A. That is, the subunit 50 provides software processing and hardware processing corresponding to the WUSB bus interface layer and the WUSB logical device layer in the WUSB protocol. Further, the controller 52 is connected to an interface 68 connected to the main unit 20 via the connection bus 12 and controls data transmission with the main unit 20.

  The other subunit B 50b connected to the main unit 20 has the same configuration as that of the subunit A 50a, is also connected to the main unit 20 via an interface, and performs wireless USB communication with the USB host B. Each of the subunit A 50a and the subunit 50b is assigned a device address independently from the connected USB host, and is identified by being assigned a unique unit identification value from the main unit 20. The number of subunits 50 connected to the main unit 20 is not particularly limited. Moreover, although the embodiment by the WUSB communication has been described above, in other embodiments, the wired USB 1. The physical layer and the MAC layer conforming to the x and USB 2.0 standards may be provided, and the subunit 50 and the USB host may be connected by wire.

  FIG. 2 is a block diagram showing an embodiment of a functional configuration of the data communication system 10 configured to include a main unit and a subunit. The data communication system 10 includes a main unit 20, a subunit 50a, and a subunit 50b. The main unit 20 includes at least one function providing unit 40 and provides a device function to a USB host that is a communication partner.

  The function providing unit 40 includes a processing unit 41 and a data flow control unit 46. The data flow control unit 46 arbitrates processing request collisions from a plurality of USB hosts requested via the subunit 50, and controls the data flow between the subunit and the main unit. The processing unit 41 executes various processes such as a printing process as an image forming apparatus in response to a processing request from each USB host. The unit identification value for identifying the connected subunit 50 is stored and managed in the unit identification value storage unit 48.

  The function providing unit 40 includes a job queue storage unit 44 for managing a process waiting for execution, and the data flow control unit 46 receives a processing request from the USB host via the subunit 50 and receives a job (processing request). ) And the unit identification value assigned to the requesting subunit 50, for example, are entered in the job queue in the order of arrival of processing requests. The data flow control unit 46 acquires data necessary for processing from the subunit 50 in the order of entry, and the processing unit 41 receives data from the data flow control unit 46 and executes processing in the order of entry in the job queue. In a process that preferably receives a series of print data, such as a print process, the data flow control unit 46 waits for completion of reception of a series of print data from the subunit 50 in progress of the job. It is possible to control the print data reading and buffering with priority. In another embodiment, while a print job from one USB host is being executed, data flow control for notifying that another USB host is working may be used.

  As another example of a device function of the main unit 20 that provides a storage function capable of random access, for each data write request or data read request from both subunits 50 (as a file fragment), It is also possible to perform control that sequentially enters the job queue, sequentially reads data from the subunit 50, writes it to a storage device such as a flash memory or HDD, or reads it from the storage device and transfers it to the subunit 50.

  In another embodiment, when an output interface function such as a speaker or a display is provided as a device function of the main unit 20, it is excluded depending on the first-come-first-served order of requests or a USB host or a USB host specified by the operation unit 28. It is good also as control utilized automatically. In another embodiment, when an input interface function such as a keyboard is provided as a device function of the main unit 20, a status is notified according to polling from a USB host communicating with each subunit 50 (interrupt transfer mode). Control may be performed. The method for arbitrating processing requests from a plurality of USB hosts and the data flow control method are not particularly limited, and a method according to the device function to be provided can be employed.

  In the embodiment shown in FIG. 2, the function providing unit 40 of the main unit 20 includes a device information storage unit 42, and enumeration with a USB host communicating with each subunit 50 (at the start of connection). At the time of initial setting), the device information of itself is notified to each USB host, and information for establishing USB communication is stored. Such information includes a device descriptor, a configuration descriptor, an interface descriptor, an endpoint descriptor, and the like, and is device information used in the USB protocol.

  On the other hand, the subunit 50 connected to the main unit 20 includes a setting storage unit 70, a data exchange unit 72, and an endpoint unit 74. The setting storage unit 70 stores a device address assigned from the connected USB host and a unit identification value assigned from the main unit 20. The endpoint unit 74 includes an endpoint zero 76 used for communication for control control, and an endpoint n for transmitting / receiving other messages and data (n represents a natural number, and a plurality of endpoints including transmission and reception) 78). The endpoint zero 76 and the endpoint n78 are given by a storage area of a memory 54 such as a RAM (Random Access Memory) or a FIFO (First In First Out) provided in each subunit 50, and communicate with the main unit 20. Temporarily buffers data transmitted to or from the other USB host. Each endpoint is assigned an identification number.

  The endpoint zero 76 and the endpoint n78 function as endpoints of data transmission from the USB host, and the USB host designates a device address and an endpoint number to transfer messages and data. On the other hand, the function providing means 40 of the main unit 20 also transmits and receives messages and data by identifying the endpoint number. Therefore, the client software on the USB host performs logical communication with the function providing means 40 of the device via each endpoint. Note that a logical communication path based on a logical connection between a buffer and an endpoint on a USB host is generally called a pipe.

  The data exchange unit 72 reads a message or data buffered at each receiving endpoint of the endpoint unit 74 when receiving a message or data from the USB host, and stores the unit identification value stored in the setting storage unit 70 And control of the process which attaches control data and transmits to the main unit 20 is performed. When the data transfer is normally completed, the end point is again shifted to the receivable state. In addition, the data exchange unit 72 receives data and messages from the main unit 20, and performs a writing process on the designated transmission endpoint of the endpoint unit 74. Note that data and messages written to the transmission end point are read under the control of the controller 52 and transferred to the USB host.

  FIG. 3 is a diagram illustrating an embodiment of a data structure of unit identification value information stored in the main unit and setting information stored in the subunit. FIG. 3A shows an embodiment of unit identification value information stored in the main unit 20. In the embodiment shown in FIG. 3A, the unit identification value information 100 includes an item field 100a, a field 100b for entering a unit identification value, and the USB device connected to each subunit is a USB host or a USB device. And a connection type field 100c for entering these.

  A record of the number of mounting slots for mounting the subunits included in the main unit 20 is prepared. The unit identification value is entered in the mounting order, and whether or not the subunit 50 is mounted in each mounting slot. If so, the identification value is managed. This unit identification value can also be used as a priority when, for example, processing requests are arbitrated. Note that the presence or absence of the field 100c for registering whether the subunit type is a host connection type or a device connection type is optional, and is not necessarily required if the system configuration is based on the assumption that a subunit to which a USB host is connected is attached. do not do.

  FIG. 3B shows an embodiment of setting information stored in the subunit A 50a. In the embodiment shown in the figure, the setting information 110 includes a field 110a for entering a unit identification value and a field 110b for registering a device address assigned by a USB host communicating with the subunit A 50a. The The field 110b can be used to determine whether or not communication with the USB host has been established. If there is a device address entry, it can be determined that communication with the USB host has been established. it can.

  FIG. 3C shows an embodiment of setting information stored in the subunit B 50b, and similarly includes a field 120a for entering a unit identification value and a field 120b for registering a device address. The subunit A 50a and the subunit B 50b are assigned device addresses independently from the USB host of each communication partner, and each USB host that communicates with each subunit specifies the communication partner by the device address. . On the other hand, the subunit A 50 a and the subunit B 50 b are specified by being assigned a unique unit identification value from the main unit 20 within the main unit 20.

  FIG. 4 is a flowchart showing an embodiment of subunit recognition processing in the main unit. First, in step S100, the main unit 20 is powered on and activated by receiving power from a bus line (in the case of wired USB, for example), and starts processing. In step S101, the main unit 20 monitors the load applied to the power supply line to the subunit, tries to detect new attachment of the subunit 50, and determines whether or not new attachment is detected in step S102. . If it is determined in step S102 that new attachment has not been detected, the process loops again to step S101 and waits for new attachment.

  On the other hand, if it is determined in step S102 that the attachment of the new subunit 50 is detected, the process branches to step S103, and the main unit 20 assigns a unit identification value to the connected subunit 50, and the unit identification value. Entry into the information 100 is performed and initial setting with the subunit 50 is performed to enable logical communication with each endpoint. After the initial setting is completed, communication between the main unit 20 and the subunit 50 becomes possible in step S104.

  Hereinafter, a control flow of device initial setting when a USB host is connected to the main unit and the subunit will be described. FIG. 5 is a flowchart illustrating an embodiment of device initialization (enumeration) between the main unit and the subunit and the USB host. In the embodiment shown in FIG. 5, it is assumed that the main unit 20 and the subunit 50 are already electrically and logically connected.

  The control shown in FIG. 5 is started in step S200 in response to a connection command issued in response to an instruction from the operator from the operation unit 28 of the main unit 20, for example. In step S201, the subunit 50 transmits a connection request to the USB host and receives a response. In step S202, the subunit 50 starts security enumeration and performs mutual authentication. In step S203, various descriptors stored in the device information storage unit are notified to the USB host in response to a GET_DISCRIPTOR command from the USB host.

  In step S <b> 204, upon receiving a device address setting request from the USB host, the subunit 50 stores the device address in its own setting storage unit 70. Further, in step S205, upon receiving a command such as SET_DESCRIPTOR or SET_CONFIGURATION from the USB host, the sub unit and the main unit perform necessary setting processing, and enter the operating state as a USB device. In step S206, data communication with the USB host is started. Note that the communication between the host and the data communication system during the enumeration described above uses a default pipe which is a logical communication path for control control composed of the endpoint zero 76 of each subunit 50. Can be done.

  FIG. 6 shows an embodiment of a data structure of a communication packet transmitted by communication between the main unit and the subunit. The inter-unit packet 130 includes a field 130 a for entering a unit identification value, a field 130 b for entering an endpoint number, and a field for entering data exchanged between the client software of the USB host and the function of the main unit 20. 130c. The inter-unit packet 130 is exchanged between the main unit 20 and each subunit 50, the subunit is identified by the unit identification value, and the interface of the function providing means 40 is identified by the endpoint number. The communication between the main unit 20 and the subunit 50 can be realized by any configuration or method as long as the main unit 20 can specify the subunit that is the transmission source or the transmission destination.

  Hereinafter, a data flow in the USB system constituted by the main unit and the subunit will be described. FIG. 7 is a schematic diagram showing a schematic configuration of a USB system including a main unit and a subunit, and two USB hosts, and an embodiment of data flow in the USB system. In the embodiment shown in FIG. 7, the USB system is formed including a data communication system 10, a USB host A 90a, and a USB host B 90b. The data communication system 10 includes a main unit 20, a subunit 50a and a subunit 50b connected to the main unit, the subunit A 50a communicates with the USB host A 90a, and the subunit B 50b communicates with the USB host B 90b. We are communicating.

  In the embodiment shown in the figure, the main unit 20 includes function providing means 40 for providing a device function corresponding to a function layer in the USB protocol. Each subunit 50 includes a WUSB logical device (USB device providing means) 80a corresponding to the USB device layer and a WUSB bus interface (bus interface providing means) 82a corresponding to the USB bus interface layer. Yes. The WUSB bus interface 82 of each subunit 50 executes substantial communication with the USB host 90 by wireless communication. The WUSB logical device 80 includes an endpoint zero 76 used for control control communication and an endpoint n78 for transmitting and receiving other messages and data.

  The WUSB bus interface 82 decodes a transaction group packet including a token and a handshake transmitted from the connected USB host 90, and responds to the USB host 90 with a handshake such as ACK or NAK as necessary. Execute. The WUSB bus interface 82 writes data included in the transaction group from the connected USB host 90 to the endpoint zero 76 or the reception endpoint n78, and the endpoint zero 76 or the transmission endpoint. The data stored in n78 is read, and data transfer is performed according to the schedule managed by the USB host 90.

  The main unit 20 is electrically connected to each subunit 50 via the connection bus 12, and the function providing means 40 exchanges data with each endpoint of each subunit 50 via the connection bus 12. Reading / writing of the endpoint zero 76, writing to the transmission endpoint n78, and reading from the reception endpoint n78 are executed.

  It should be noted that some end points n78 used for the same purpose constitute an interface. For example, when the main unit 20 provides a printer function, the function providing means 40 for providing the printer function includes: The interface includes a print control interface and a print data reception interface, and the USB host 90 performs data transfer with the interface according to the request process.

  On the other hand, each USB host 90 includes client software 92 corresponding to the function layer, WUSB system software 94 corresponding to the USB device layer, and a USB host controller 96 corresponding to the USB bus interface layer. . The USB host controller 96 controls a transaction group with the subunit 50 and exchanges data and messages with the WUSB bus interface 82 of the subunit 50.

  The USB system software 94 manages a logical communication path (pipe) between a buffer (configured by the memory 26) on the USB host and each endpoint of the subunit 50, and the endpoint 50 of the subunit 50 Device functions provided by the main unit 20 and the subunit 50 are managed using a default pipe 84 that is a logical connection for control control with the zero 76a.

  The client software 92 manages the interface of the main unit 20 using a pipe bundle 86 associated with the set of endpoints of the subunit 50. In order to use the device function, the client software 92 sends a data transfer request between the buffer on the USB host 90 and each endpoint of the connected subunit 50 by an I / O request packet (IRPs). Communication with the function providing means 40 of the main unit 20 is performed, and the device function is used.

  That is, the client software 92 of each USB host 90 provides data transfer with the endpoint n78 of the subunit 50 to be connected, and provides functions with the endpoint n78 by electrical and logical connection between the main unit 20 and the subunit 50. Through the communication of the means 40, it is possible to access the function providing means 40 of the main unit 20 and use the device function. In that case, the function providing means 40 specifies the request source by the unit identification value, executes the request processing under the job management by the data flow control unit 46, and provides the device function to each USB host 90. It is possible. Hereinafter, an embodiment of job management in the data flow control unit 46 will be described with reference to the data structure of job management data.

  FIG. 8 is a diagram illustrating an embodiment of a data structure of job management data used for request processing arbitration processing and data flow control in the data communication system. FIG. 8 illustrates an embodiment in which the data communication system 10 functions as an image forming apparatus and executes printer processing. In the embodiment shown in FIG. 8, the job management data 140 includes a field 140a for entering a job number, a field 140b for entering a unit identification value, and a field for entering a waiting job.

  The data flow control unit 46 of the function providing unit 40 receives, for example, a processing request such as a print request and enters the job management data 140 managed by the job queue storage unit 44 in the order of job numbers. The data flow control unit 46 looks up the job management data 140, preferentially acquires data necessary for request processing in the order of entry of the job management data 140, and monitors the working state of the processing unit 41 while processing the processing unit 41 The processing request and data are transferred to 41. The processing unit 41 executes the received job and returns a processing response to the data flow control unit 46 as necessary. The data flow control unit 46 deletes the entry upon completion of the job and executes a process of decrementing the job number of the other entry.

  In the example shown in FIG. 8, a print request is received from the USB host A 90a communicating with the subunit 50 having the unit identification value [1], and “print job 1” is set in the job number [1] of the job management data 140. Has been entered. In order to read the print data from the subunit 50 having the unit identification value [1] according to the job management data 140, the data flow control unit 46 acquires the data from the endpoint and instructs the processing unit 41 to start the printing process. To do. The print job 2 received from the subunit 50 having the unit identification value [1] and the print job 1 received from the subunit 50 having the unit identification value [2] received after starting the processing of the job number [1] are managed by the job management. After all of the print data that is entered in the lower part of the data 140 and is used when executing the print job 1 with the job number [1] is acquired, it is sequentially started and processed.

  While the data acquisition related to the upper-level job is preferentially performed, the reading process from the data transfer endpoint of the other subunit 50 is awaited. In addition, data acquisition from one subunit 50 can be controlled such that the connection bus is preferentially used by the subunit 50 that is acquiring data. The waiting subunit 50 responds a negative handshake such as NAK or NYET to the USB host sending the data transfer request, and controls to wait for data transmission from the USB host.

  As a USB device, the configuration includes a main unit 20 connected to a plurality of subunits 50 having functional means of the logical device layer, and means for identifying the subunits and controlling request processing execution and data flow between the units. The data communication system 10 is recognized as a USB logical device by a plurality of USB hosts at the same time, and can identify a requesting USB host and execute a request process. Convenience as a USB device and data between USB devices The degree of freedom of flow can be improved. In this case, no modification of software and hardware processing on the USB host side is requested. Further, the configuration having the data flow control means makes it possible to smoothly execute request processing from each USB host even when processing requests from a plurality of USB hosts collide, and it is convenient as a USB device. Can be improved.

  In addition, by separating the main unit 20 and the sub unit 50, it is possible to install the sub unit for wired connection and the sub unit for wireless communication separately according to the usage environment. It is possible to reduce a simple component configuration (for example, a configuration for supporting both wired and wired connections).

  As described above, the data communication system 10 including the main unit 20 and the subunit 50 has been described as an embodiment in which the data communication system 10 functions only as a USB device. However, in other embodiments, the data communication system 10 can also be configured as a dual-role device that conforms to the USBOTG (USB On The Go) standard (ie, functions simultaneously as both a USB host and a USB device). Further, it is possible to provide a data flow between USB devices with a higher degree of freedom. In that case, the subunit 50 can be configured to include an OTG controller that executes control for functioning as a USB host and a USB device, or a host controller for functioning as a USB host. Hereinafter, more flexible data flow control between the main unit and the subunit will be described.

  In FIG. 9, a main unit 20, a subunit A 50a that communicates with a USB host, and a USB device (hereinafter, an external device that is a device on the USB protocol regardless of a wired / wireless protocol is referred to as a USB device. ) Shows a schematic configuration of an embodiment of the data communication system 10 including a subunit B 50b that communicates with. In the illustrated embodiment, the data communication system 10 includes a main unit 20, a subunit A 50a that communicates with a USB host, and a subunit B 50b that communicates with a USB device. The main unit 20 includes a function module 43 that implements functional means of the function layer. Each subunit 50 includes a USB bus interface module 83 that realizes the functional means of the USB bus interface layer, and a USB device module 81 that realizes the functional means of the USB device layer.

  In the embodiment shown in the figure, the main unit 20 includes a bus path selection unit 160, the normal mode in which the subunit 50 communicates with the function module 43 of the main unit 20, and the USB bus interface interface of the subunit 50. The modules 83 are connected to each other and can be switched to a bridge operation mode that functions as a repeater. The operation unit 28 including an operation panel of the main unit 20 receives a switching instruction between the normal mode and the bridge operation mode, and issues a path switching request to the path management unit 29 in response to an instruction from the operator. The route management unit 29 that has received the request issues a route switching command to the bus route selection unit 160 to switch between the normal operation mode and the bridge operation mode. That is, the path management unit 29 functions as a means for controlling a logical data flow between the main unit 20 and the subunit 50 and between subunits via the main unit 20.

  In the bridge operation mode, it is not preferable that the USB hosts or the USB devices are connected to each other. Therefore, it is determined whether the connected subunit A 50a and the subunit B 50b are both USB hosts or both are USB devices. If the combination is determined to be a combination of a USB host and a USB device, control for switching to the bridge operation mode may be performed. Such a determination can be made, for example, by calculating exclusive OR using the unit identification value information 100 for the entry in the field 100c with the USB host as “true” and the USB device as “false”. Yes, but it can be determined by any method.

  In the embodiment shown in FIG. 9, the bus connection between the main unit 20 and the subunit 50 includes the bus line 150 connecting the USB bus interface module 83 of each subunit 50 and the main unit 20, and the USB device module. 81 and a bus line 152 connecting the main unit 20. The bus line 150 and the bus line 152 are connected to the bus route selection unit 160, and the bus route selection unit 160 is connected to the bus line 156 connected to the function module 43, and inside the bus line 156, the bus line 156 A switch 158a and a switch 158d for switching the connection between the line 152a and the bus line 152b are included. Further, the bus path selection unit 160 includes a bus line 156 for connecting the bus lines 150 to each other, and a switch 158b and a switch 158c for switching the connection.

  In the switch 158a to 158d, in the normal operation mode, the switch 158a and the switch 158d are turned on, and the switch 158b and the switch 158c are turned off. In the bridge operation mode, the switch 158a and the switch 158d are turned off, and the switch 158b and the switch 158c are turned on.

  In the bridge operation mode, subunits having wired USB connectors function as hubs or repeaters, and the connection distance can be extended. In the connection between a subunit with a wired USB connector and a subunit with a wireless WUSB antenna, it functions as a media converter such as a host wire adapter or device wire adapter. In a mixed usage environment, the degree of freedom of data flow between USB devices can be further improved. Subunits equipped with wirelessly connected WUSB antennas function as relays, and the communicable distance of wireless USB connection can be extended.

  In the above description, the operation in the bus route selection has been described with the embodiment of the configuration of the main unit connected to the two subunits. However, it may be a case where it is connected to three or more subunits. If so, it could be easily expanded. When connecting to three or more subunits, one subunit that communicates with the USB host and a plurality of subunits that communicate with the device are selectably connected to function as a USB hub. be able to. In that case, it can be realized by configuring as a sub unit or a main unit having functional means for providing a hub function such as a repeater, a hub controller, a transaction translator, and a routing logic.

  In FIG. 10, the schematic block diagram which shows other embodiment of the data communication system 10 which performs mode switching is shown. In the embodiment shown in FIG. 10, the normal mode in which the function providing means 40 of the main unit 20 communicates with the bus route selecting unit 170 of the main unit 20 and the bus route selecting unit 172 of the subunit 50, and the subunit The 50 USB bus interface modules 83 are connected to each other, and the bridge operation mode that functions as a repeater is switched. An operation unit 28 including an operation panel of the main unit 20 can receive an instruction to switch between the normal mode and the bridge operation mode, and issues a route switching request to the route management unit 29 in response to an instruction from the operator. To do. Upon receiving the request, the route management unit 29 issues a switching command to the bus route selection unit 170 and the bus route selection unit 172 of each subunit 50 to switch the mode.

  In the embodiment shown in FIG. 10, the route management unit 29 that has received a command to switch to the normal mode issues a command to turn on the switch 174 of the bus route selection unit 170 and simultaneously selects the bus route of each subunit 50. A command for switching to the normal mode is issued to the unit 172. Receiving the command, each bus path selection unit 172 turns on the switch 176 for switching the bus line connecting the USB device module 81 and the main unit 20 to connect the USB bus interface module 83 and the main unit 20. A switch 178 for switching the bus line is turned off.

  In response to the switching instruction to the bridge operation mode, the path management unit 29 issues a command to turn off the switch 174 of the bus path selection unit 170, and sends the USB device module 81 to the bus path selection unit 172 of each subunit 50. The switch 176 for switching the bus line connecting the main unit 20 and the main unit 20 is turned off, and the switch 178 for switching the bus line connecting the USB bus interface module 83 and the main unit 20 is turned on. With the configuration of the subunit 50 including the bus route selection unit 172, it is possible to reduce the complexity of the bus line between the main unit 20 and the subunit 50.

  FIG. 11 is a schematic configuration diagram showing still another embodiment of the data communication system 10 that performs mode switching. In the embodiment shown in FIG. 11, the same configuration as the main unit 20 and the subunit 50 including the bus path selection unit as in the embodiment shown in FIG. 10 is provided, and mode switching is instructed from the subunit 50 side. It is an embodiment. The subunit 50 includes a switching instruction unit 88 such as a button switch that waits for a switching instruction from an operator. The switching instruction unit 88 controls the path switching of the bus path selection unit 172 of each subunit 50, and controls the path selection of the bus path selection unit 172 in response to the mode switching command from the main unit 20. .

  For example, the switching instruction unit 88b of the subunit B 50b that has received an instruction to switch to the bridge operation mode by the operator executes the route switching of the bus route selection unit 172b, and at the same time, the bridge operation mode Switch notification to. Receiving the switching notification from the subunit B 50b, the route management unit 29 turns off the switch 174 of the bus route selecting unit 170 and issues a mode switching instruction to the switching instruction unit 88a of the subunit A 50a. Upon receiving the instruction, the switching instruction unit 88a of the subunit A 50a switches the route of the bus route selection unit 172a.

  With the configuration in which the subunit 50 includes an operation mode switching instruction unit, even if the main unit does not include an operation unit such as an operation panel, the operation mode switching instruction is issued by simple instruction means such as a button switch of the subunit. Can be done.

  In the following, an embodiment of the manner of mounting the main unit 20 and the subunit 50 will be described. FIG. 12 is a schematic diagram showing an embodiment of a mounting manner of the main unit 20 and the two subunits 50. In the embodiment shown in FIG. 12A, the subunit 50 is configured as a wireless USB including a directional antenna 64. In the figure, each subunit 50 is mounted in the slot, and the direction of the directional antenna 64 of each subunit 50 is different. By adopting a configuration of a subunit including a directional antenna, radio wave interference between the subunits 50 can be suitably reduced even when the subunits 50 are arranged close to each other.

  FIG. 12B shows another embodiment of the manner of mounting the main unit 20 and the two subunits 50. FIG.12 (c) is a side view which shows the side surface 20b of the main unit 20 at the time of seeing the main unit 20 from the arrow Y direction in the figure of FIG.12 (b). In the drawing, a state in which a slot 49b for mounting the subunit 50 is provided on the side surface 20b of the main unit 20 is shown. Similarly, the other side surface is provided with a slot 49a (not shown), and the subunit 50 can be mounted in the slot 49a. With the configuration of the main unit 20 having a slot in which the subunit 50 is mounted at a distance, radio wave interference between the subunits 50 can be suitably reduced. Furthermore, in the embodiment shown in FIG. 12B, the mounting slot 49 is arranged on the side surface that constitutes the opposite side of the main unit, and can further reduce radio wave interference.

  The data communication system 10 including the main unit 20 and the subunit 50 has been described with the embodiment in the case of providing a device function as an image forming apparatus, but the device provided by the data communication system. The function is not particularly limited. The data communication system can also be provided with a device function as an imaging device such as a digital camera, an image reading device such as a scanner, and a recording device such as a storage device.

  As described above, according to the present invention, a data flow that is connected to and recognized by a plurality of USB hosts, performs processing in response to requests from the plurality of USB hosts, and has a high degree of freedom between USB devices is provided. A data communication system, a unit, and a data communication method can be provided.

  The present invention also provides a data communication system, a unit, and a data communication method that can function as a USB repeater with a simple operation and enable highly flexible data flow control between USB devices. be able to.

  Further, the above functions of the present invention can be realized by a device executable program described in a legacy programming language such as an assembler, C, C ++, C #, Java (registered trademark), an object-oriented programming language, or the like. , EEPROM, EPROM, flash memory, flexible disk, CD-ROM, CD-RW, DVD, SD memory, MO and the like can be stored and distributed.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and those skilled in the art have conceived other embodiments, additions, modifications, deletions, and the like. It can be changed within the range that can be performed, and any embodiment is included in the scope of the present invention as long as the operation and effect of the present invention are exhibited.

The block diagram which shows embodiment of the hardware constitutions of the data communication system comprised including a main unit and a subunit. The block diagram which shows embodiment of the function structure of the data communication system comprised including a main unit and a subunit. The figure which shows embodiment of the data structure of the unit identification value information stored in a main unit, and the setting information stored in a subunit. The flowchart which shows embodiment of the recognition process of the subunit in a main unit. The flowchart which shows embodiment of the device initial setting of a main unit and a subunit, and a host. The figure which shows embodiment of the data structure of the communication packet transmitted by communication with a main unit and a subunit. 1 is a schematic diagram illustrating an embodiment of data flow between a data communication system and two hosts. FIG. The figure which shows embodiment of the data structure of the job management data used for the arbitration process of request processing in a data communication system, and data flow control. The schematic block diagram which shows embodiment of the data communication system which can switch modes. The schematic block diagram which shows other embodiment of the data communication system which can switch modes. The schematic block diagram which shows other embodiment of the data communication system which can switch modes. Schematic which shows embodiment of the mounting | wearing style of a main unit and a subunit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Data communication system, 12 ... Connection bus, 20 ... Main unit, 22 ... CPU, 24 ... ROM, 26 ... Memory, 28 ... Operation part, 29 ... Path management part, 30 ... Display part, 32 ... Memory | storage device, 34 ... Printer, 36 ... Interface (I / F), 38 ... Internal bus, 40 ... Function providing means, 41 ... Processing unit, 42 ... Device information storage unit, 43 ... Function module, 44 ... Job queue storage unit, 46 ... Data flow control unit, 48 ... unit identification value storage unit, 49 ... slot, 50 ... subunit, 52 ... controller, 54 ... memory, 56 ... wireless communication unit, 58 ... NVRAM, 60 ... physical layer (UWB BB PHY), 62 ... Physical layer (UWB RF PHY), 64 ... Antenna, 66 ... MAC (medium access control) layer, 68 ... Interface, 70 ... Setting storage unit, 7 ... Data exchange part, 74 ... Endpoint part, 76 ... Endpoint zero, 78 ... Endpoint n, 80 ... WUSB logical device, 81 ... USB device module, 82 ... WUSB bus interface, 83 ... USB bus interface Module 84 ... Default pipe 86 86 Pipe bundle 88 Switch instruction section 90 USB host (external device) 92 Client software 94 USB system software 96 USB host controller 100 ... Unit identification value information, 110 ... Setting information, 120 ... Setting information, 130 ... Inter-unit packet, 140 ... Job management data, 150, 152, 154, 156 ... Bus line, 158 ... Switch, 160, 170, 172 ... Bus Route selector, 174, 176, 178 ... switch

Claims (12)

A data communication system that includes a main unit and at least one subunit, and executes data communication with an external device using a USB protocol,
The main unit is
A function providing means for providing a function as a USB device; and a data flow control means for identifying the subunit and controlling data transmission with the subunit;
The subunit is
A bus interface providing means for executing signal transmission with the external device, a USB device providing means for receiving arbitration by the data flow control means, and a data exchanging means with the main unit.
Data communication system. The USB device providing means provides an endpoint for establishing a logical communication path with the external device as a USB host,
The data exchange means performs data exchange between the endpoint and the main unit;
The data communication system according to claim 1. The data flow control means includes
Identify the subunit of data source or destination,
Controlling the data transmission with the subunit in response to a processing request or an external command from the external device;
The data communication system according to claim 1 or 2. A main unit having a slot for mounting at least one subunit, and capable of executing data communication with an external device using a USB protocol,
The main unit is
A main unit comprising function providing means for providing a function as a USB device, and data flow control means for controlling data transmission with the subunit in response to a processing request or an external command from the external device . The main unit is
The main unit according to claim 4, wherein the plurality of slots are spaced apart. A subunit that is attached to a main unit for providing a function as a USB device, and that can execute data communication with an external device using a USB protocol,
The subunit is
A bus interface providing means for executing signal transmission with the external device, a USB device providing means, and a data exchanging means with the main unit;
Sub unit. The USB device providing means provides an endpoint for establishing a logical communication path with the external device as a USB host,
The data exchange means performs data exchange between the endpoint and the main unit;
The subunit according to claim 6. The subunit is
The subunit according to claim 6 or 7, further comprising data flow control means for controlling data transmission with the main unit in response to an external command. The subunit comprises a directional antenna;
The subunit according to any one of claims 6 to 8. The subunit includes an instruction means for receiving an external command for switching data flow.
The subunit according to any one of claims 6 to 9. A data communication method using a USB protocol between a data communication system including a main unit and at least one subunit and an external device,
The data communication method includes:
Establishing a logical communication path between the subunit and the external device;
Transferring data according to the USB protocol via the logical communication path;
Exchanging the data between the subunit and the main unit so that the subunit can be identified;
Data communication method. The data communication method includes:
Executing request processing in response to the data;
Controlling the exchange of the data in response to the request processing or an external command,
The data communication method according to claim 11.

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