CN100476777C - USB interface with host/device function and control method thereof - Google Patents

Abstract

A USB interface with USB host/device function and its control method, the USB interface can combine with function circuit to form a USB apparatus with USB host/device function, include a control unit, a host computer unit, a device unit, a memory cell, a router and multiple connection ports. The control unit defines the connection port as an uplink port or a downlink port, controls the signal flow in the USB control interface, transmits the signal flow to the host unit and the device unit according to the requirement, the storage unit stores the temporary storage data when the USB control interface operates, the host unit is connected with an external device through the router, and the device unit is connected with an external host through the router.

Description

USB interface with host/device function and control method thereof

technical field

The present invention relates to a universal serial bus (Universal Serial Bus, USB) multifunctional interface and its control method, especially to a USB interface with USB host/device function and its control method.

Background technique

In order to solve the problem of complex connection interfaces between computers and their auxiliary equipment in the traditional world, the Universal Serial Bus (USB) specification was proposed in 1996 to provide a single-standard output/input interface for different external auxiliary equipment. After the release of the USB1.0 specification, it has undergone many revisions to meet the needs of the market and designers. For example, the USB1.1 released in 1998 added a new transmission specification (interrupt OUT), and the USB2 released in 2000 .0 supports high-speed (Hi-speed) specifications and adds a mini-B interface (mini-B connector), and also defines a new descriptor (descriptor). Subsequently, the USB OTG specification was proposed in 2001 to achieve Better power management and the purpose of allowing the same device to work in different forms.

During the evolution of the USB specification, the host-device architecture has been maintained. Please refer to Figure 1, which is a USB Physical Bus topology (Physical Bus) disclosed in the Universal Serial Bus specification Revision 2.0 (Universal Serial Bus specification Revision 2.0) proposed by the USB Implementers Forum in 2000. Topology) schematic diagram. It can be seen from FIG. 1 that a USB system 100 can be composed of a host (Host) 110 and a device (Device) 120 through a bus connection interface (Inter-connection), wherein the device 120 can be classified into a general device, a compound device (Compound Device) and a hybrid device (Composite Device).

Now make a more detailed definition of the above-mentioned components: a host has a host controller (Hostcontroller) and a hub (Root Hub), the root hub has at least one port (Port), and the host computer undertakes a large number of tasks in the USB system. Portion control works as well as communication. A function is to provide a specific capability (capability) for auxiliary identification of the host, such as a mouse, a keyboard, and the like. A hub (hub) has an up-stream port (up-stream port) and at least one down-stream port (down-stream port), and the up-stream port is used for connecting with a host, and the down-stream port is used for embedding ) or an external device for connection. A device is a function, a hub, or a combination thereof. A composite device has a hub and at least one function, so that a host regards the connected composite device as a hub and at least one physical device connected to the hub. device), each of the physical devices has an independent address. For example, a keyboard and a trackball can be integrated into a composite device. Inside the device, these individual functions are permanently connected to a hub, It can also be called a "composite hub". In terms of the host, a compound device is like a separate hub connected with other functions, as shown in Figure 1, the part framed by the box on the lower right is a compound hub (CompoundHub). Both the hub and the device have an independent address. A hybrid device is a functional device with a plurality of independent interfaces defined by a descriptor stored in the device. A hybrid device has only one address, but each of the interfaces has a different function and can be controlled independently. For example, a hybrid device may have both an interface for an audio device and another interface for a control panel.

The working principle of the USB system is briefly described as follows: the bus connection interface of the USB is a tiered star topology, and this kind of stacking can reach up to 6 layers. At the center of each stack is a hub (HUB). Each line segment is a connection between a host and a hub/function, a hub and another hub/function, or node-to-node. In the topology arrangement of USB shown in FIG. 1 , each node represents a device or function. When a USB system is activated, the device addresses in the system are all 0, and then the system searches for devices and assigns addresses to devices sequentially until all devices have the specified address, or the upper limit of the number of USB devices is reached .

According to the above, it can be found that all data transmission in a USB system must be controlled by the host to start the operation, all USB devices are slave devices (Slaver), must obey the established agreement and respond to the transmission from the Host, and then use Standard USB data format for receiving and transmitting data. Compared with the peer-to-peer architecture used in traditional connection ports, the USB system implements a master-slave architecture, using a host to complete the control of multiple devices.

In this way, the USB architecture uses a transmission line to connect various types of auxiliary equipment in series, and instead of traditional auxiliary equipment, various cables are needed, such as the parallel port cable of the printer, the serial port cable of the modem, etc. Simplifies the connection between external auxiliary devices and the host, and has advantages such as Plug-and-Play, "Hot Attach&Detach", low power consumption, high versatility, and low cost .

However, with the rise of consumer electronics, especially the market of mobile devices (such as mobile phones, PDAs, and multimedia players, etc.), based on the complexity of mobile device usage occasions, in order to reduce the dependence on the host and make mobile devices In order for the information to be accessed quickly, the USB specification must be modified to provide better power management and allow the device to work as both a host and a device.

To this end, the USB Developers Forum launched USB OTG 1.0 in December 2001. After six revisions, USB OTG 1.0a was launched in June 2003, officially becoming a practical specification. Please see Figure 2, the device type function diagram defined for USB OTG. USB OTG defines two device types: Peripheral-Only Device (POD) and Dual-Role Device (DRD). The function of a single device is similar to that of a general device, while a dual-purpose character device has two functions of a USB-standard host and a device. Because of this, the dual-purpose character device must have a new function of role switching. As shown in Figure 2, it can be seen that a device with a dual-purpose role device function can have two functions as a host and a device. For example, a mobile phone can be connected to a host to become a device, and can also be connected to a device to drive the device. end host.

As a supplement to USB2.0, OTG1.0 also defines three connectors: Mini A plug and socket, MiniB plug and socket, and Mini AB socket. In the USB-OTG specification, device A represents the master device and acts as a host, and generally refers to a dual-purpose device that works as a host, and device B represents a slave device and acts as a single device. The Mini AB socket is a specification designed for dual-purpose role devices to allow the insertion of Mini A or Mini B plugs, and with the help of the inserted plugs, defines the initial role of the dual-purpose role device (such as a host or device) to actuate ( enable) its host or device unit. The Mini A socket is designed on the host and used to connect the Mini A plug of the peripheral device. Similarly, the Mini B socket is designed on the device to connect the Mini B plug. Therefore, different socket types distinguish different USB devices.

In the OTG specification, two dual-role devices can alternately work as a host and a slave when connected. This feature is compatible with the structure of the existing USB host/device. The host computer of OTG specification is also responsible for the task of initializing data communication. For example: bus reset (reset), obtain various USB descriptors and configure devices, etc. After the configuration is completed, the two OTG devices can transmit information in the mode of master and slave respectively. Wherein, the process of master-slave role exchange between two devices is defined by a host negotiation protocol (HNP).

In addition, in the OTG device, there is only one connection port, and the connection with the host end and the device end is realized through the connection port, so that the OTG device lacks expandability, thereby limiting the application and market value of the OTG specification.

Contents of the invention

An object of the present invention is to provide a USB interface with a host/device function and a control method thereof. The USB interface can drive a plurality of devices to construct an independent USB system.

Another object of the present invention is to provide a USB interface with a host/device function and a control method thereof, the USB interface is respectively connected to a plurality of external devices and an external host, and the external host can use the USB interface and The function of the external device.

Another object of the present invention is to provide a USB interface with host/device function and its control method. When the USB interface is connected to an external host, it is regarded as a hybrid device, and the USB interface bridges multiple external devices. As for the external host, the host regards the external device as a function of the USB interface.

Another object of the present invention is to provide a USB interface with host/device function and its control method, the USB interface includes a router (router) and a plurality of connection ports, the control unit can define any of the connections The port is an uplink port or a downlink port.

Another object of the present invention is to provide a USB interface with host/device function and its control method, the USB device includes a control unit (Control Unit), a host unit (USB HostUnit), a device unit (USB Device Unit) and a storage unit, the control unit controls the data transmitted to the host unit and the device unit, and the storage unit is used to store the data required for calculation when the USB interface performs data processing.

Another object of the present invention is to provide a USB interface with a host/device function and a control method thereof, the USB interface includes a router and a plurality of connection ports, and the control unit is connected to any of the connection ports by means of detection Whether an external device provides power to the method of the connection port, define the connection port as an uplink port or a downlink port, when the external device provides power, the connection port is defined as an uplink port, when the When the external device does not provide power, the connection port is defined as a downstream port.

Another object of the present invention is to provide a USB device with host/device function. The USB interface can be combined with functional circuits to form a USB device (Apparatus) with USB host/device function.

Another object of the present invention is to provide a USB device with a host/device function. When the USB device is only connected to at least one external device, the USB device can drive multiple devices to construct an independent USB system. When the USB device is connected to an external host and at least one external device, the USB device is regarded as a hybrid device, and the USB device bridges the external device and the external host so that the external host can The external device is directly used through the present invention without an additional hub.

Another object of the present invention is to provide a USB interface control method with host/device functions, by detecting whether the external device connected to the USB interface connection port provides power, to define the connection port as an uplink port or an uplink port row port.

Yet another object of the present invention is to provide a USB interface control method with host/device functions, by pre-calibrating device functions or simulating disconnection and re-connection in an electrical manner so as to re-register new The device function realizes the hot plug (Hot Plug) feature of the USB device.

In order to achieve the above object, the present invention provides a USB interface with a host/device function, comprising:

A plurality of connection ports for connecting with USB devices;

A router, connected to the connection port, the control unit defines the connection port as one of an uplink port and a downlink port;

a host unit connected to the router, and when any connection port is defined as a downstream port, the router bridges the downstream port to the host unit; and

A device unit connected to the router, when any connection port is defined as an uplink port, the router bridges the uplink port to the device unit, and defines other connection ports as a downlink port;

A control unit, connected with the router, the host unit and the device unit, receives the status of the connection port to control the data flow of the USB interface.

With the help of one of the modes most suitable for implementing the present invention through simple demonstration, those skilled in the art will be able to understand one or part or all of the features and advantages of the present invention from the following descriptions. Therefore, the accompanying drawings and the description can basically be regarded as Exemplary rather than limiting.

Description of drawings

FIG. 1 is a schematic diagram of a USB Physical Bus Topology.

Figure 2 is a functional diagram of a device type defined by USB OTG.

FIG. 3 is a schematic block diagram of a USB control interface with host/device functions according to a preferred embodiment of the present invention.

FIG. 4 is a control flow diagram according to a preferred embodiment of the present invention.

5A and 5B are schematic diagrams of the connection relationship and work of the USB control interface 300 in the Stand Alone mode and the USB external device.

FIG. 6A and FIG. 6B are schematic diagrams of the connection relationship and operation between the USB control interface 300 and the USB external device in the device mode.

Detailed ways

FIG. 3 is a schematic block diagram of a USB control interface with host/device functions according to a preferred embodiment of the present invention. The USB control interface 300 includes a control unit 310 , a host unit 320 , a device unit 330 , a storage unit 340 , a router 350 and a plurality of connection ports 360A, 360B. The control unit 310 is respectively connected to the host unit 320, the device unit 330, the storage unit 340 and the router 350, and the control unit 310 controls the USB control interface, such as commands (Command), Data (Data) and status (Status) signals and other signal flows (flows), and according to the connection port status defined by the control unit 310 (for example, an uplink port or a downlink port), the signal flow is transmitted to the The host unit 320 and the device unit 330 . The storage unit 340 stores data required for the operation of the USB control interface. The router 350 is connected to the connection ports 360A and 360B. After the control unit 310 defines the connection ports 360A and 360B as an uplink port or a downlink port, it is connected with the device unit 330 or the host unit 320 by means of the router 350 coupling. The definition method of the uplink port or the downlink port is to detect whether the external equipment connected to the connection ports 360A and 360B provides power, and when the connected external equipment provides power, the connection port is defined as an uplink port, so The external device is an external host; when the connected external device does not provide power, the connection port is defined as a downstream port, and the external device is an external device. It is worth noting that the number of the connection ports It can be a specified number, and is not limited to two groups. The number of connection ports in this embodiment is only for illustration, and should not be regarded as a limitation of the present invention. The host unit 320 is respectively connected to the control unit 310 and the router 350, and is connected to any one of the connection ports defined as a downstream port through the router 350 to connect to an external device. At this time, the USB The function of the control interface is a host interface. It should be noted that the number of the host unit 320 can be a specified number and is not limited to one. The number of the host unit 320 in this embodiment is only for illustration and should not be regarded as a limitation of the present invention. The device unit 330 is respectively connected to the control unit 310 and the router 350, and is connected to the connection port defined as an uplink port through the router 350, so as to be connected to an external host computer. At this time, the control unit 310 defines other connection ports as downstream ports, and the function of the USB control interface is a device-end interface.

Since the connection ports 360A and 360B are defined as uplink ports or downlink ports, it is determined by the control unit 310 to detect whether the external device provides power, and then the control unit 310 controls the router 350 to bridge the uplink port to the device unit 330, or to bridge the downlink port to the device unit 330. host unit 320 and the like. Therefore, according to the present invention, the bridge 350 is only an optional component, if the connection port 360A or 360B is an A or mini A socket, it is directly bridged to the device unit 330; the connection port 360A or 360B is a B or mini B type socket, it is directly bridged to the host unit 320, that is, no router 350 is required. If the connection port 360A or 360B is a Mini-AB socket, the appearance of the connector on the connection line is similar, so a router 350 can be installed to bridge the uplink port to the device unit 330 via the control unit 310 and connect the downlink port to the host unit 320 .

Please refer to FIG. 4 , which is a control flow chart according to a preferred embodiment of the present invention. Step 40 uses the control unit 310 to detect whether there is an external device connected to the connection port 360A or 360B. When an external device is connected, step 41 detects whether the external device provides power through the connection port connected to it, such as the external device. When the device does not provide power, in step 42 , the control unit 310 defines the connection port connected to the external device as a downstream port, and bridges the downstream port to the host unit 320 . If the external device provides power, go to step 43 , the control unit 310 defines the connection port connected with the external device as an uplink port, and bridges the uplink port to the device unit 330 . Then in step 44 define the remaining connection ports as downlink ports, and bridge the downlink ports to the host unit 320 . Then, proceed to step 45, continuously detect the connection port, if another external host is connected to another connection port, the problem of two hosts existing at the same time can be solved.

The following is a more clear description of the connection relationship and working mode between the USB control interface 300 with the host/device function and the external device in different working modes:

Please refer to FIG. 5A and FIG. 5B, which are the connection relationship and working schematic diagram of the USB control interface 300 in Stand Alone mode and the USB external device. For the convenience of description, the connection ports 360A and 360B are defined as the first connection Port 360A' and second connection 360B'. In FIG. 5A, an external device 370 is connected to the first connection port 360A'. Since the USB control interface 300 detects that the external device 370 fails to provide power, the first connection port 360A' is defined as a downstream The port is connected to the host unit 320 through the router 350 . Therefore, the USB control interface 300 can use the functions of the external device, such as printing, scanning, accessing or playing data, etc., but not limited thereto. In FIG. 5B, the external device 370 is connected to the second connection port 360B'. Since the USB control interface 300 detects that the external device 370 fails to provide power, the second connection 360B' is defined as the following The port is connected to the host unit 320 through the router 350 . Therefore, the USB control interface 300 can use the functions of the external device, such as printing, scanning, and accessing or playing data, but not limited thereto. 5A and 5B show the working diagram of the USB control interface 300. With the use of the router 350, no matter whether an external device is connected to any of the connection ports, it can be bridged to the host unit 320. In this way, the USB control interface 300 can use the functions of the external device. Regardless of any changes in the number of the connection ports and the connection ports to which the external device is connected, the aforementioned independent mode operation of the USB control interface 300 is still valid.

Please refer to FIG. 6A and FIG. 6B , which are schematic diagrams of the connection relationship and work of the USB control interface 300 in the device mode and the USB external device. In FIG. 6A, an external host 380 is connected to the second connection port 360B'. Since the USB control interface 300 detects that the external host 380 provides power, the second connection port 360B' is defined as an uplink port. Connected to the device unit 330 through the router 350, the control unit 310 defines the first connection port 360A' as a downstream port, connected to the external device 370, and the external device 370 passes through the router 350 is bridged to the host unit 320. In this embodiment, the USB control interface 300 is defined as a composite device (Composite Device) interface in the device (Device) mode, and the external device 370 is regarded as a function of the USB control interface 300, but also Not limited thereto, for example, the USB control interface 300 can also be defined as a compound device interface in the device mode.

In FIG. 6B, an external host 380 is connected to the first connection port 360A'. Since the USB control interface 300 detects that the external host 380 provides power, the first connection port 360A' is defined as an uplink port. Connected to the device unit 330 through the router 350, the control unit 310 defines the second connection port 360B' as a downstream port, connected to the external device 370, and the external device 370 passes through the router 350 is bridged to the host unit 320.

If the USB control interface 300 according to the present invention is in the stand alone mode and an external host is connected to the connection port of the USB control interface 300, the USB control interface 300 will switch to the device mode. However, before switching to device mode, you can wait for the operation in standalone mode to complete to ensure the correctness of the data.

The data access and transmission paths in Fig. 5 and Fig. 6 of this embodiment are described as follows: an external host is connected to the router through the uplink port, and communicates with the control unit through the device unit, and the control unit then passes through the host The unit and the downlink port obtain the information and data required by the external device to perform functions, and use the storage unit to store the data required for operation and transmission. Accordingly, when the external host performs functions, the operation relationship between the external host/external device can be realized through the path.

It should be noted that the specific types of USB devices shown in FIG. 5 and FIG. 6 of this embodiment are only examples and should not be regarded as limitations of the present invention. In fact, any device that uses a USB interface for data access can be The invention can realize the connection between the external host and the external device.

In addition, the present invention provides two control methods, so that the USB control interface 300 can realize the function of USB interface hot plug (Hot Plug) in the device (Device) mode, which is described in detail below:

When the function of the external device is predetermined, the host side can identify/enumerate the predetermined function to realize the hot plug function of the USB. Firstly, regardless of whether the USB control interface 300 is connected to an external device or not, when an external host is connected to the USB control interface 300, at least one predetermined function is marked (Book). Then, when a pre-determined external device is connected to the USB control interface 300, the function can be activated to use the external device. For example, a removable storage function (Removable Disk Function) or a user interface function (Human Interface Function) can be marked in advance, and when the external device inserted later has the marked function, it can be used immediately. It should be noted that the number and types of pre-marked functions can be determined by system requirements and performance, and are not limited to one.

Another USB interface hot-swapping method is to use the design of the USB control interface 300. Under the condition that the USB control interface 300 and an external host end are in the same state, when another external device passes through When the USB control interface 300 is connected to the external host, the USB control interface 300 is used to automatically disconnect the external host (Disconnect, that is, connect the D+ and D- pins to a logic low level) and reconnect (Re-connect, that is, when the D+ or D- pin is connected to a pull-up (pull-up) resistor), the external host can use the USB interface device to mark the external device as one of its interfaces to detect The existence of the external device, and identify and drive the external device, so as to realize the hot plug function of the USB interface.

It is worth mentioning that the aforementioned connection is not limited to wired connection and electrical connection, and the connection methods that are sufficient to enable signal transmission between each connection unit according to system requirements should be considered as disclosed by the present invention. For example, For example, the signal transmission method in the Wireless USB specification (Wireless USB) can also be used in the present invention.

The USB interface with host/device functions described in the present invention can be combined with functional circuits to form a USB device (Apparatus) with USB host/device functions. In other words, through the use of the present invention, it can be integrated into any Electronic devices that use USB interfaces, such as desktop computers, laptop computers, flash drives, digital audio-visual players, mobile phones, GPS devices, PDA devices, and various input and output devices, are USB devices with USB host/device functions. The USB device can not only directly use the above-mentioned level device, but also enable an external host to use the functions of the USB device itself, and can also be connected to other external devices through the USB device to directly use the external device. functions of the device without changing the cable connection between the external host, the USB device and the external device. Therefore, through the use of the USB interface, the aforementioned various electronic devices can become USB devices with USB host/device functions, thus having excellent convenience and compatibility, and greatly increasing the market value.

Those skilled in the art should understand that the specific embodiments of the present invention shown in the above drawings and descriptions are exemplary and non-limiting.

The foregoing descriptions of preferred embodiments of the invention have been presented for purposes of illustration and description. The invention is not intended to be limited to the precise forms or exemplary embodiments disclosed. Accordingly, the foregoing description should be considered as illustrative rather than restrictive. Obviously many modifications and variations will be apparent to those skilled in the art. The selection and description of specific embodiments are in order to better explain the principles of the present invention and the best mode for its practical application, thereby allowing those skilled in the art to understand the present invention for various specific embodiments, and have the characteristics suitable for specific uses or Various modifications of the covered implementations. It is intended that the scope of the invention be defined by the scope of the claims appended hereto and their equivalents, with all claims to include their broadest reasonable scope unless otherwise stated. It will be appreciated that changes may be made to the particular embodiments by those skilled in the art without departing from the scope of the invention as defined by the scope of the claims hereinafter.

Claims (11)

1. USB interface with host machine/apparatus function, in order to connect at least one external equipment, this USB interface comprises:

A plurality of connectivity ports, each described connectivity port are used for coupling with a described external equipment;

One control module one of defines described connectivity port and is in a uplink port and the descending port;

One main computer unit is coupled to described control module, when being defined as described downlink port, can bridge to described downlink port one of in described connectivity port;

One device unit is coupled to described control module, when being defined as described uplink port, can bridge to described uplink port one of in described connectivity port, and other persons that defined in the described connectivity port by described control module are described downlink port.

2. USB as claimed in claim 1 interface is characterized in that also comprising a router, is coupled to described control module, in order to the described main computer unit of bridge joint to described downlink port and the described device unit of bridge joint to described uplink port.

3. USB as claimed in claim 1 interface is characterized in that also comprising a storage unit, couples with described control module, in order to storage data.

4. USB as claimed in claim 1 interface is characterized in that whether described control module provides power supply by detecting the described external equipment that described connectivity port connected, and is one of described uplink port and described downlink port to define described connectivity port.

5. USB as claimed in claim 4 interface is characterized in that when described external equipment does not provide power supply the connectivity port that is connected with described external equipment is defined as described downlink port, and the described downlink port of bridge joint is to described main computer unit.

6. USB as claimed in claim 5 interface, it is characterized in that when described external equipment provides power supply, the connectivity port that is connected with described external equipment is defined as described uplink port, the described uplink port of bridge joint is to described device unit, and to define other connectivity ports be described downlink port, and the described downlink port of bridge joint is to described main computer unit.

7. USB as claimed in claim 4 interface, it is characterized in that when described external equipment provides power supply, the connectivity port that is connected with described external equipment is defined as described uplink port, the described uplink port of bridge joint is to described device unit, and to define other connectivity ports be downlink port, and the described downlink port of bridge joint is to described main computer unit.

8. USB as claimed in claim 4 interface, it is characterized in that being described downlink port when described connectivity port with a described external equipment bridge joint, then this described external equipment is defined as an external device, then described USB interface under a stand-alone mode, the described external device of direct access.

9. USB as claimed in claim 8 interface, it is characterized in that when with the described connectivity port of a described external equipment bridge joint in one of during for described uplink port, then this described external equipment is defined as an external main frame, then described USB interface is under a device pattern, make that described external main frame can be the one interface by the built-in function at described external device of described USB interface mark and described USB interface, directly uses the built-in function at described external device and described USB interface.

10. USB as claimed in claim 4 interface, it is characterized in that when with the described connectivity port of a described external equipment bridge joint in one of during for described uplink port, then this described external equipment is defined as an external main frame, other described external equipments all are defined as an external device, then described USB interface is under a device pattern, make that described external main frame can be the one interface by the built-in function at described external device of described USB interface mark and described USB interface, directly uses the built-in function at described external device and described USB interface.

11. the control method with host machine/apparatus function USB interface comprises the following steps:

Detect a plurality of connectivity ports and whether couple external equipment;

When described external equipment connects, detect described external equipment and whether provide power supply by connected described connectivity port;

If described external equipment does not provide power supply, the described connectivity port that definition is connected with described external equipment is a descending port, and described downlink port to a main computer unit of bridge joint; If described external equipment provides power supply, the described connectivity port that definition is connected with described external equipment is a uplink port, and described uplink port to a device unit of bridge joint, and the described connectivity port that defines other is described downlink port, and bridge to described main computer unit; And

Whether detect described external equipment is removed.

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