TWI685752B - Usb hub - Google Patents

Abstract

A USB hub includes a upstream port coupled to a first host; a first USB device control unit, coupled to the upstream port, for performing packet format conversion; an FIFO circuit coupled to the first USB device control unit for storing data from the first host; a second USB device control unit, coupled to the FIFO circuit, for performing packet format conversion; and a plurality of downstream ports, coupled to the second USB device control unit. When any one of the downstream ports is coupled to a mobile device, if the first host commands the mobile device to switch from a device role to a host role, the mobile device temporally disconnects from the USB hub and the first host commands the USB hub to change an internal routing path. When the mobile device is switched to the host role, the first host is the host role, the first USB device control unit is the device role, the mobile device is the host role and the second USB device control unit is the device role. The first host and the first USB device control unit are paired while the mobile device and the second USB device control unit are paired.

Description

Universal serial bus hub

The invention relates to a composite universal serial bus (USB) hub with host-to-host function.

In the past, when a mobile device was connected to a host (notebook computer, desktop computer, or car system) via a USB (Universal Serial Bus), the mobile device was regarded as a device (device ) (That is, from the device).

However, mobile devices (such as smart phones) are becoming more and more popular and have powerful hardware functions. Therefore, mobile devices may gradually replace the roles of laptop computers, desktop computers, or car systems. That is, the mobile device has transitioned from a device to a host.

In addition, due to the huge application of USB, devices with USB host functions (such as mobile phones/desktop computers/notebooks, etc.) may need to connect a USB hub (Hub) to connect other peripheral USB devices. However, in terms of the original design of the USB hub, the USB hub has an upstream port to connect to the host and multiple downstream ports to connect to other peripheral USB devices. However, the downstream port of the USB hub only has the host-to-device function, and does not have the host-to-host function. However, with the rapid development of mobile devices, the host-to-host operation mode has become an inevitable trend.

That is, there is a need for a new USB hub design that can support both "host-to-host" and "host-to-device" modes of operation. When in host-to-host mode, the mobile device is connected to the downstream port of the USB hub design, but the mobile device still operates as the host.

According to an example of the present case, a universal serial bus (USB) hub is proposed. The USB hub includes: an upstream port coupled to a first host; and a first USB device control unit coupled to the upstream port for To perform packet format conversion; a first-in first-out circuit, coupled to the first USB device control unit, for temporarily storing data transmitted from the first host; and a second USB device control unit, coupled to the The first-in first-out circuit is used for packet format conversion; and a plurality of downstream ports are coupled to the second USB device control unit. When any one of the downstream ports is coupled to a mobile device, if the first host orders the mobile device to switch from a device role to a host role, the mobile device temporarily disconnects from the USB hub Connection, and the first host orders the USB hub to switch its internal winding path. After the mobile device switches to the host role, the first host still plays the role of the host, and the first USB device control unit plays the role Device role, the mobile device plays the role of the host, the second USB device control unit plays the role of the device, the first host and the first USB device control unit are paired, the mobile device and the second USB device control unit are In pairs.

According to another example of the present case, a universal serial bus (USB) hub is proposed. The USB hub includes: an upstream port coupled to a first host; and a hub function module coupled to the upstream port for Perform a hub function; a host-to-host functional module, coupled to the upstream port, when a mobile device connected to the USB hub performs a device role, through the control of the hub functional module, the first host and The signal between the mobile devices flows through a bypass path or the host-to-host functional module, the host-to-host functional module implements a "host-to-host mode"; at least one control module is coupled to the upstream port, Control at least one connected device; a virtual hub functional unit, coupled to the hub functional module, the host-to-host functional module and the at least one control module, the virtual hub functional unit supports a virtual hub function and has The function of storing the relationship between the USB address and related devices. The virtual hub function unit stores a plurality of virtual USB addresses; and a plurality of downstream ports, coupled to the second USB device control unit. According to a USB address specified by the first host, the virtual hub functional unit specifies the respective virtual USB addresses of the hub functional module, the host-to-host functional module and the at least one control module.

In order to have a better understanding of the above and other aspects of the present invention, the following examples are specifically described in conjunction with the accompanying drawings as follows:

The technical terms of this specification refer to the idioms in the technical field. If this specification describes or defines some terms, the interpretation of these terms shall be based on the description or definition of this specification. Each embodiment of the present disclosure has one or more technical features. Under the premise of possible implementation, those skilled in the art can selectively implement some or all of the technical features in any of the embodiments, or selectively combine some or all of the technical features in these embodiments.

Referring now to FIG. 1, a functional block diagram of a USB hub according to an embodiment of the present case is shown. As shown in FIG. 1, the USB hub 130 includes: an upstream port 131, a plurality of downstream ports 132, a hub function module 141, a host-to-host function module 142, a first control module 143, a second control module 144 and Interface 151 and 152. The first host (such as a desktop computer, notebook computer, car system, etc.) 110 is connected to the upstream port 131 of the USB hub 130 through a USB interface, and the mobile device (such as a smartphone, etc.) 120 is connected to the The downstream port 132 of the USB hub 130.

The hub function module 141 is used to perform general hub functions (ie, for example, signal transmission between a host and a device).

When a mobile device (for example, a smart phone, etc.) 120 connected to the USB hub 130 performs a device role, the signal between the first host 110 and the mobile device 120 flows through the bypass through the control of the hub function module 141 The path BY does not flow through the host-to-host functional module 142. Conversely, when the mobile device 120 (for example, a smartphone, etc.) 120 connected to the USB hub 130 switches from the device role to the host role, through the control of the hub function module 141, the first host 110 and the mobile device 120 The signal flows through the host-to-host functional module 142 without flowing through the bypass path BY. That is to say, in the embodiment of the present invention, the "host-to-host mode" can be implemented by the host-to-host function module 142, and the details will be described below.

The first control module 143 and the second control module 144 control the connected devices through the interfaces 151 and 152. For example, the first control module 143 may have a storage device control function, and the second control module 144 may have a sound effect device control function. Although FIG. 1 shows two control modules 143 and 144, this case is not limited to this. In other possible embodiments of this case, the hub 130 may include a greater number of control modules.

Refer now to FIG. 2, which shows a functional block diagram of the USB hub 200 according to an embodiment of the present case. As shown in FIG. 2, the USB hub 200 according to an embodiment of the present case includes: a repeater 210, a transaction translator 212, a routing logic 214, and a state machine 216, USB device control unit 218, virtual hub function unit 220, FIFO (first in first output) circuit 222, USB device control unit 224, storage control unit 226, audio control unit 228, upstream port 242, plural Downstream ports 244_1-244_N (N is a positive integer), and interfaces 246_1 and 246_2.

The repeating circuit 210 is used to copy the signal/data transmitted from the first host and transmit it to the transmission translation circuit 212 or the winding logic circuit 214. The architecture and details of the repeating circuit 210 will not be described here.

The transmission and translation circuit 212 controls the high-speed and low-speed/full-speed data transactions, realizes the data packet conversion between the upstream port and the downstream port at different speeds, and performs other functions to ensure that different speed data on the bus can be correctly transmitted. When the transmission translation is performed, the packet from the first host flows through the repeating circuit 210 and the transmission translation circuit 212, and reaches the winding logic circuit 214; when the transmission translation is not required, the packet from the first host It flows through the repeating circuit 210 and reaches the winding logic circuit 214. The structure and details of the transmission and translation circuit 212 will not be described here.

The winding logic circuit 214 is responsible for winding the data, so that the data is transmitted between the upstream port 242 and the downstream ports 244_1-244_N. The structure and details of the winding logic circuit 214 will not be described here.

The state machine 216 can decode the signal/data transmitted from the first host to determine which downstream port the signal/data should be transmitted to. The state machine 216 may be composed of hardware plus firmware. The architecture and details of the state machine 216 will not be described here.

The USB device control unit 218 can be executed by hardware or firmware. When the packet transmitted from the first host is to be sent to USB peripheral devices of different USB types, the USB device control unit 218 performs format conversion on the packet. Similarly, when a packet transmitted from a USB peripheral device of a different USB type is to be sent to the first host, the USB device control unit 218 performs format conversion on the packet. The architecture and details of the USB device control unit 218 will not be described here.

The virtual hub function unit 220 is used to enable the USB hub to support compound devices and/or composite devices, details of which will be described below. In addition, in the embodiment of the present invention, the virtual hub function unit 220 supports a virtual hub (Virtual hub) function and has a function of designating a virtual USB address. A plurality of virtual USB addresses are stored in the virtual hub function unit 220. The state machine 216, the USB device control unit 218 and the virtual hub function unit 220 may constitute a hub control unit.

The FIFO (First In First Out) circuit 222 is between the USB device control units 218 and 224 (or between the USB device control unit 218 and the storage control unit 226, or between the USB device control unit 218 and the sound control unit Between 228) to temporarily store the data transmitted by the first host and/or USB peripheral device and/or mobile device and transfer it to the first host and/or USB peripheral device and/or mobile device. The details will be explained below with reference to Figure 3.

The USB device control unit 224 can be executed by hardware or firmware. The USB device control unit 224 has the same or similar functions as the USB device control unit 218. In addition, in the embodiment of the present invention, when the mobile device 120 is switched from the device role to the host role, the USB device control units 218 and 224 both play the device role (wherein, the first host 110 and the USB device control unit 218 are a pair, The mobile device and the USB device control unit 224 are a pair) to implement the host-to-host mode of the embodiment of the present invention. In detail, it is assumed that the mobile device 120 is connected to the downstream port 244_1. When the mobile device 120 plays the role of a device, the signal paths between the first host 110 and the mobile device 120 are: upstream port 242, repeating circuit 210 (and/or transmission translation circuit 212), winding logic circuit 214, and downstream port 244_1 .

When the first host 110 orders the mobile device 120 to switch from the device role to the host role, the mobile device 120 temporarily disconnects from the hub 200, and the first host 110 also commands the USB hub 200. In response to this command, the winding logic circuit 214 switches its internal winding path. After the mobile device 120 switches to the host role, the signal paths between the first host 110 and the mobile device 120 are: upstream port 242, repeating circuit 210, USB device control unit 218, first-in first-out circuit 222, USB device control unit 224 , The winding logic circuit 214 and the downstream port 244_1. That is, after the mobile device 120 switches to the host role, the first host 110 still plays the host role, and the USB device control unit 218 still plays the device role; on the other hand, the mobile device 120 plays the host role, and the USB device control unit 224 still Play the role of device. With this, the embodiment of the present invention can achieve the host-to-host mode.

The storage control unit 226 may be a card reader controller of the memory card, which is used to control the memory card connected to the interface 246_1 of the USB hub 200. Alternatively, the storage control unit 226 may be an external hard disk controller for controlling a hard disk drive connected to the interface 246_1 of the USB hub 200. Of course, this case is not limited to this. The architecture and details of the storage control unit 226 will not be described here.

The audio control unit 228 can be used to control peripheral audio devices (such as speakers or microphones) connected to the interface 246_2 of the USB hub 200. The architecture and details of the audio control unit 228 will not be described here.

The upstream port 242 can be connected to a first host (such as the first host 110 in FIG. 1). The downstream ports 244_1-244_N can be connected to USB peripheral devices (such as, but not limited to, USB flash drives, USB external hard drives, etc.). In addition, any of the downstream ports 244_1-244_N can be connected to the mobile device 120.

Now please refer to Figure 1 and Figure 2 again. In FIG. 1, the hub functional module 141 is implemented by, for example, the repeating circuit 210, the transmission translation circuit 212 and the winding logic circuit 214. The host-to-host functional module 142 is implemented by, for example, a USB device control unit 218, a first-in first-out circuit 222, and a USB device control unit 224. The first control module 143 is implemented by a USB device control unit 218, a first-in first-out circuit 222, and a storage control unit 226, for example. The second control module 144 is implemented by, for example, a USB device control unit 218, a first-in first-out circuit 222, and an audio effect control unit 228. In other words, in the embodiment of the present invention, the hub function module 141, the host-to-host function module 142, the first control module 143, and the second control module 144 may share some units with each other.

The USB device control unit 218, the FIFO (First In First Out) circuit 222 and the USB device control unit 224 can perform the host-to-host mode of the USB hub 200 or the built-in data buffer. How the embodiment of this case implements the "host-to-host mode" has been described above.

In the embodiment of the present invention, when the role of the mobile device is to be switched from the device to the host, the first host sends a custom command (Vendor command) to the USB hub 200 to change the internal signal path of the USB hub 200 (as described above) , To achieve the "host-to-host function", but does not affect other downstream ports 244_1-244_N and/or upstream ports 242 that are in transit.

Or, in the USB hub 200 of this embodiment, the USB device control unit 224 can automatically determine the USB device descriptor (USB Device Descriptor) of the mobile device connected to any downstream port 244_1-244_N (if the USB device descriptor is Instruct the mobile device to play the role of host) to determine whether it is necessary to switch from host-to-device transfer mode to host-to-host transfer mode (change the internal signal path of USB hub 200 as described above) and initiate device mode conversion, but does not affect other Downstream ports 244_1-244_N and/or upstream ports 242 being transmitted.

For example, assume that the downstream port 244_1 is connected to a mobile device and the downstream port 244_2 is connected to a USB flash drive. When the mobile device still assumes the role of the device, in the winding logic circuit 214 (please refer to FIG. 2), the signal path of the mobile device is P1, and the signal path of the USB flash drive is P2. When the mobile device switches to the role of host, in the winding logic circuit 214 (please refer to FIG. 2), the signal of the mobile device changes to the path P3, while the signal of the USB flash drive still follows the path P2. That is to say, in the embodiment of the present case, when the first host orders to switch the role of the mobile device from the device role to the host role, it will not affect the data transmission of other downstream ports.

FIG. 3 shows a functional block diagram of the FIFO circuit 222 according to the embodiment of the present invention. As shown in FIG. 3, the FIFO circuit 222 includes: FIFOs 302 and 304, multiplexers 306 and 308, a DMA direct memory access circuit 310 and a multiplexer 312. The FIFO 302 is coupled between the USB device control units 218 and 224. In addition, the FIFO 304 is coupled to the USB device control units 218 and 224 through multiplexers 306 and 308, respectively.

In the embodiment of the present invention, the FIFO circuit 222 supports a fast data transmission path, so that data can be stored in the USB device control unit 218, FIFO 302, multiplexer 312, and USB device control unit 224 (and/or storage control unit 226 and/or The sound effect control unit 228) is quickly transmitted, and the data passing through this path will not be modified by the central processor 322.

In addition, in the embodiment of the present invention, if the data may need to be processed by the central processor 322 before being transmitted to the other end, the data transmission process is as follows. The following uses the example of transferring data from the first host to the mobile device as an example. Those skilled in the art can infer the process of transferring the data from the mobile device to the first host. The data sent by the first host is written into the FIFO 304 through the USB device control unit 218 and the multiplexer 306. Next, the DMA circuit 310 temporarily stores the data from the FIFO 304 and the multiplexer 308 to the buffer 320 of the first host 110. After the central processing unit (CPU) 322 of the first host 110 processes/modifies the data in the buffer 320, the central processing unit (CPU) 322 informs the DMA circuit 310. The DMA circuit 310 writes the modified/processed data from the buffer 320 to the FIFO 304 through the multiplexer 306, and then the FIFO 304 passes through the multiplexer 308 and the multiplexer 312 to transfer the data in the FIFO 304 It is sent to the USB device control unit 224 for transmission to the mobile device, or to the storage control unit 226 for transmission to the storage device (not shown), or to the sound effect control unit 228 for transmission to the sound effect device (not shown).

Or, in the embodiment of the present invention, if the CPU 322 wants to transmit data to a mobile device or a storage device or an audio device, the CPU 322 can store the data in the buffer 320 first, and then temporarily pass through the DMA circuit 310 and the multiplexer 306 Save to FIFO 304, and then send the data in FIFO 304 to the USB device control unit 224 through the multiplexer 312 to the mobile device, or to the storage control unit 226 to the storage device (not shown), or It is sent to the sound effect control unit 228 for transmission to a sound effect device (not shown).

Or, in this embodiment, the data is written into the FIFO 304 by the first host through the USB device control unit 218 and the multiplexer 306, and then, the DMA circuit 310 stores the data from the multiplexer 308 into the buffer 320, and waits until After the CPU 322 has modified/processed the data, the CPU 322 informs the DMA circuit 310. The DMA circuit 310 reads the modified/processed data from the buffer 320 and writes it to the FIFO 304 via the multiplexer 306, but does not It is passed to the USB device control unit 224, storage control unit 226, and sound effect control unit 228. The modified/processed data is stored in the FIFO 304 and can be read out later if necessary.

In the embodiment of the present invention, a mobile device (such as a smart phone) can be used as a host or a device.

Now please refer to FIGS. 4A to 4C, which show schematic diagrams of the application side according to the embodiment of the present application. In the application diagram of FIG. 4A, for the first host 110, the first host 110 can learn the "hub function module 141, host-to-host function module 142, first control The group 143 and the second control module 144 belong to the same layer, that is, they belong to the "Composite device". When implementing the application diagram shown in FIG. 4A, the first host will assign a USB address (here, but not limited to, the USB address is 5) to this integrated device (this integrated device includes the hub function module 141 , Host-to-host function module 142, first control module 143 and second control module 144). That is, the hub function module 141, the host-to-host function module 142, the first control module 143, and the second control module 144 share the USB address 5.

When the USB hub 200 receives the command/data from the first host, the hub function module 141 checks the "interface field" in the USB address of the command/data to determine the command/data Which one of the hub function module 141, the host-to-host function module 142, the first control module 143, and the second control module 144 is to be transmitted to.

Similarly, in the application diagram of FIG. 4B, for the first host 110, the hub function module 141, the first control module 143, and the second control module 144 belong to the same layer, that is, to the same integrated device . Logically, the host-to-host functional module 142 is regarded by the first host 110 as being connected to the downstream port of the hub functional module 141.

When implementing the application diagram shown in FIG. 4B, the first host will assign a USB address (here, but not limited to, the USB address is 5) to the upper-layer integrated device, which includes the hub function module 141, The first control module 143 and the second control module 144. That is, the hub function module 141, the first control module 143, and the second control module 144 share the USB address 5. Moreover, the first host will assign a USB address (here, but not limited to, the USB address is 6) to the host-to-host function module 142. The virtual hub function unit 220 of the USB hub 200 can store the relationship between the USB addresses 5-6 and their corresponding devices.

When the USB hub 200 receives the command/data from the first host, the USB hub 200 checks the USB address of the command/data. If the USB address of the command/data is 6, the USB hub 200 transmits the command/data to the host-to-host function module 142. If the USB address of the command/data is 5, the USB hub 200 does not Commands/data are sent to the next layer, but to the upper integrated device. In addition, if the USB address of the command/data is 5, the USB hub 200 checks the “interface field” in the command/data to determine whether the command/data should be sent to the hub function module 141, the first One of a control module 143 and a second control module 144.

Similarly, in the application diagram of FIG. 4C, for the first host 110, the hub function module 141 has its own layer, and the host has the host function module 142, the first control module 143, and the second control module 144. It belongs to the same layer (same integrated device). Logically, the first host 110 regards the integrated device as a downstream port connected to the hub function module 141. When implementing the application diagram shown in FIG. 4C, the first host will assign a USB address (here, but not limited to, the USB address is 5) to the hub function module 141. Moreover, the first host will assign a USB address (here, but not limited to, the USB address is 6) to the lower-level integrated device. The integrated device includes a host-to-host function module 142, a first control module 143 and Second control module 144. The virtual hub function unit 220 of the USB hub 200 stores the relationship between the USB addresses 5-6 and their corresponding devices.

When the USB hub 200 receives the command/data from the first host, the USB hub 200 checks the USB address of the command/data. If the USB address of the command/data is 5, the hub function module 141 receives the command/data. In addition, if the USB address of the command/data is 6, the USB hub 200 will check the “interface field” in the command to determine whether the command/data should be sent to the host-to-host function module 142, the first control mode Which one of the group 143 and the second control module 144?

That is, in an application case, after the mobile device is switched from the USB device mode to the USB host mode, the mobile device can support the first host, and the first host still maintains the USB host mode. In this way, the first host can connect to other USB peripheral devices through other downstream ports of the USB hub 200 to perform transmission and application between the first host and other USB peripheral devices. Supporting the first host by the mobile device means that, for example, when the first host is an in-vehicle system, the mobile device can display a screen on the screen of the first host, and allow the user to operate the mobile device by operating on the first host, It is as if the user is directly operating the mobile device. For example, the user can operate on the first host to use the route guidance provided by the mobile device, make calls, send and receive messages, and listen to music.

In summary, in the embodiment of the present invention, according to the custom command sent by the first host, the USB hub 200 can switch the internal signal path to support the host-to-host function, and this internal signal path switch does not affect other transmissions. Signal path.

In addition, as described above, through the virtual USB hub function (storage of USB addresses) of the USB hub 200, a variety of application-side situations (such as FIGS. 4A to 4C) can be supported, increasing flexibility in use.

In summary, although the present invention has been disclosed as above with examples, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention belongs can make various modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be deemed as defined by the scope of the attached patent application.

110‧‧‧ First host 120‧‧‧Mobile device 130‧‧‧USB hub 131‧‧‧Upstream port 132-134‧‧‧Downstream port 141‧‧‧Hub function module 142‧‧‧Host-to-host functional module Group 143‧‧‧ First control module 144‧‧‧ Second control module 151 and 152‧‧‧ Interface BY‧‧‧ Bypass path 200‧‧‧USB hub 210‧‧‧Repeat circuit 212‧‧‧ Transmission Rendering circuit 214‧‧‧Winding logic circuit 216‧‧‧ State machine 218, 224‧‧‧USB device control unit 220‧‧‧ Virtual hub function unit 222‧‧‧First in first out circuit 226‧‧‧ Storage control unit 228 ‧‧‧Audio control unit 242‧‧‧Upstream port 244_1-244_N‧‧‧Downstream port 246_1-246_2‧‧‧Interfaces P1, P2, P3‧‧‧ Paths 302 and 304‧‧‧FIFO306, 308, 312 Multiplexer 310‧‧‧ Direct Memory Access (DMA) circuit 320‧‧‧Buffer 322‧‧‧Central Processing Unit (CPU)

FIG. 1 shows a functional block diagram of a USB hub according to an embodiment of the present case. Figure 2 shows a functional block diagram of a USB hub according to an embodiment of the present case. Fig. 3 shows a functional block diagram of the FIFO circuit according to the embodiment of the present invention. 4A to 4C show schematic diagrams of the application side according to the embodiment of the present application.

200‧‧‧USB hub

210‧‧‧Repeat circuit

212‧‧‧ Transmission and Translation Circuit

214‧‧‧ winding logic circuit

216‧‧‧ State Machine

218, 224‧‧‧USB device control unit

220‧‧‧ Virtual Hub Functional Unit

222‧‧‧First in first out circuit

226‧‧‧Storage control unit

228‧‧‧Audio control unit

242‧‧‧Upstream port

244_1-244_N‧‧‧ downstream port

246_1, 246_2‧‧‧‧Interface

P1, P2, P3‧‧‧path

Claims (2)

A universal serial bus (USB) hub, the USB hub includes: an upstream port, coupled to a first host; a hub function module, coupled to the upstream port, for performing a hub function; The host-to-host functional module is coupled to the upstream port. When a mobile device connected to the USB hub performs a device role, the control between the first host and the mobile device is controlled by the hub functional module. The signal flows through a bypass path or the host-to-host functional module, which implements a "host-to-host mode"; at least one control module, coupled to the upstream port, controls at least one of the connected Device; a virtual hub functional unit, coupled to the hub functional module, the host-to-host functional module and the at least one control module, the virtual hub functional unit supports a virtual hub function and has a storage USB address and related The function of the relationship between the devices, the virtual hub function unit stores a plurality of USB addresses; and the plurality of downstream ports are coupled to a second USB device control unit, based on a USB address specified by the first host, The virtual hub function unit specifies respective virtual USB addresses of the hub function module, the host-to-host function module and the at least one control module. The USB hub as described in item 1 of the patent application scope, wherein the USB hub determines a transmission target of the command according to an interface field in a command transmitted from the first host.

Images