TWM671029U - Usb repeater device - Google Patents

Abstract

The USB repeater device includes a USB-host-side port, a USB-device-side port, a first repeater, a second repeater and a control circuit. The USB-host-side port is coupled to an input terminal of the first repeater and an output terminal of the second repeater. The USB-device-side port is coupled to an output terminal of the first repeater and an input terminal of the second repeater. The control circuit detects the signal of the USB-host-side port and the signal of the USB-device-side port to dynamically determine an operation mode. When the operation mode is a waiting transaction-start mode, the first repeater operates in a standby state, and the second repeater operates in a power-off state. When the operation mode is a waiting transaction-finish mode, the first repeater and the second repeater transmit transactions between the USB-host-side port and the USB-device-side port.

Description

USB Repeater Device

This novel invention relates to a signal transmission system, and in particular to a Universal Serial Bus (USB) repeater device.

When high-speed signals pass through transmission paths such as cables or printed circuit boards, the signal attenuation is very serious. Generally speaking, the longer the signal transmission distance, the more serious the signal attenuation (that is, the worse the signal quality), which makes it difficult for the receiver at a distance to restore the transmitted signal. Repeaters are used in USB hosts, USB cables or USB devices to improve the signal quality of the transmission path.

The Universal Serial Bus (USB) specification specifies the L0, L1, L2, and L3 states of link power management (LPM). The L1 state is the sleep state. The L2 state is the suspend state. The L3 state is the power-off state. A repeater that enters the L1, L2, or L3 state can save power. The L0 state is the normal working state. In the L0 state, the repeater can be enabled to transmit transaction signals in real time. However, how to reduce the power consumption of a repeater that enters the L0 state is one of the many technical issues in the USB field.

The present invention provides a Universal Serial Bus (USB) repeater device to reduce power consumption in normal working state (such as L0 state specified by USB specification).

In one embodiment of the present invention, the USB repeater device includes a USB host side port, a USB device side port, a first repeater, a second repeater, and a control circuit. The input end of the first repeater is coupled to the USB host side port. The output end of the first repeater is coupled to the USB device side port. The input end of the second repeater is coupled to the USB device side port. The output end of the second repeater is coupled to the USB host side port. The control circuit detects the signal of the USB host side port and the signal of the USB device side port to dynamically determine the operation mode. In response to the operation mode being a waiting transaction-start mode, the control circuit controls the first repeater to operate in a standby state, and the control circuit controls the second repeater to operate in a power-off state to save power. In response to the operation mode being a waiting transaction-finish mode, the control circuit controls the first repeater and the second repeater to transmit at least one transaction between the USB host side port and the USB device side port.

Based on the above, the USB repeater device described in the embodiments of the present invention can detect the signals of the USB host side port and the USB device side port in real time in the normal working state (such as the L0 state specified by the USB specification) to dynamically determine the operation mode. When the USB host side port and the USB device side port are both idle for a long time, the USB repeater device enters the transaction start waiting mode. Each transaction starts with the USB host sending the first packet to the USB device in a unidirectional manner, and then the USB host and the USB device perform bidirectional transaction transmission. When the operation mode is the transaction start waiting mode, the USB repeater device detects the signal of the USB host side port in real time to wait for the start of the next transaction. During the waiting period for the "start of the transaction", it can be determined that the USB device will not send a signal to the USB host, so the second repeater operates in a power-off state to save power. Therefore, the USB repeater device can reduce power consumption in normal working state.

In order to make the above features and advantages of this novel creation more clearly understood, the following is a specific example and a detailed description with the attached diagrams.

100:Signal transmission system

110:Host

111: Universal Serial Bus (USB) host controller

112, 132, 200: USB repeater device

120:USB cable

130: Device

131: USB device controller

210: USB host port

220: USB device port

230, 240: Repeater

231, 241: Equalizer

232, 242: Driver

250: Control circuit

251, 252: Signal detector

253:Controller

DS_idle_event, HS_idle_event: idle event

HS&DS_idle_timeout_event: long-term idle event

M41: Waiting for transaction start mode

M42: Waiting for transaction to end mode

M51: Host to device direction mode

M52: Two-way standby mode

M53: Device to host direction mode

S310, S320, S330, S340: Steps

S_in_DS_event, S_in_HS_event: signal switching event

Figure 1 is a block diagram of a signal transmission system of this novel invention.

Figure 2 is a circuit block diagram of a USB repeater device of an embodiment of the present invention.

Figure 3 is an operation flow chart of the USB repeater device of an embodiment of the present invention.

Figure 4 is a schematic diagram of the operation mode of the USB repeater device of an embodiment of the present invention.

Figure 5 is a schematic diagram of the operation mode of a USB repeater device in another embodiment of the present invention.

Figure 6 is a circuit block diagram of a repeater and a control circuit of an embodiment of the present invention.

The term "coupled (or connected)" used in the entire specification of this case (including the scope of the patent application) may refer to any direct or indirect means of connection. For example, if the text describes a first device coupled (or connected) to a second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be indirectly connected to the second device through other devices or some connection means. The terms "first", "second", etc. mentioned in the entire specification of this case (including the scope of the patent application) are used to name the elements or distinguish different embodiments or scopes, and are not used to limit the upper or lower limit of the number of elements, nor to limit the order of elements. In addition, wherever possible, elements/components/steps with the same numbers in the drawings and embodiments represent the same or similar parts. Elements/components/steps using the same number or the same terminology in different embodiments can refer to each other for related descriptions.

FIG1 is a block diagram of a signal transmission system of the present invention. The signal transmission system 100 of FIG1 includes a host 110, a Universal Serial Bus (USB) cable 120 and a device 130. The USB cable 120 is connected between the host 110 and the device 130, so that the host 110 and the device 130 communicate with each other through the USB cable 120. In this embodiment, a USB repeater device is used in the transmission path between the USB host controller 111 of the host 110 and the USB device controller 131 of the device 130 to perform a repeating function in the signal transmission system 100. The USB repeater device can regenerate the signal to improve the signal quality of the signal transmission system 100. The location and number of the USB repeater device can be determined according to the actual design and application. The USB repeater device of this embodiment can be a retimer device or a redriver device. For example, the USB repeater device 112 can be arranged between the USB host controller 111 and the USB cable 120, and (or) the USB repeater device 132 can be arranged between the USB device controller 131 and the USB cable 120 to improve the signal quality.

For example, the USB host side port of the USB repeater device 112 is coupled to the USB host controller 111. In an application, the USB host side port of the USB repeater device 112 includes a data channel, such as a differential pair Dp and Dn (or recorded as D+ and D-) that complies with the USB2 specification, or a differential pair eDp and eDn (or recorded as eD+ and eD-) that complies with the embedded USB2 (eUSB2) specification. The USB device side port of the USB repeater device 112 is coupled to the USB cable 120. The USB device side port of the USB repeater device 112 includes a data channel, such as a differential pair Dp and Dn that complies with the USB2 specification.

The USB host side port of the USB repeater device 132 is coupled to the USB cable 120. The USB host side port of the USB repeater device 132 includes a data channel, such as a differential pair Dp and Dn that complies with the USB2 specification. The USB device side port of the USB repeater device 132 is coupled to the USB device controller 131. In an application, the USB device side port of the USB repeater device 132 includes a data channel, such as a differential pair Dp and Dn that complies with the USB2 specification or a differential pair eDp and eDn that complies with the eUSB2 specification.

FIG. 2 is a circuit block diagram of a USB repeater device of an embodiment of the present invention. The USB repeater device 200 shown in FIG. 2 can be used as one of many implementation examples of any one of the USB repeater devices 112 and 132 shown in FIG. 1 . The USB repeater device 200 shown in FIG. 2 can refer to the relevant description of the USB repeater device 112 or 132 shown in FIG. 1 . In the embodiment shown in FIG. 2 , the USB repeater device 200 includes a USB host side port 210, a USB device side port 220, a repeater 230, a repeater 240, and a control circuit 250. The control circuit 250 detects the data channel signal of the USB host side port 210 and the data channel signal of the USB device side port 220 to dynamically determine the operation mode of the USB repeater device 200. According to different designs, the control circuit 250 can be implemented as a hardware circuit or a combination of hardware, firmware, and software (i.e., program).

In terms of hardware, the control circuit 250 can be implemented as a logic circuit on an integrated circuit. For example, the relevant functions of the control circuit 250 can be implemented in various logic blocks, modules and circuits in one or more hardware controllers, microcontrollers, hardware processors, microprocessors, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), central processing units (CPUs) and/or other processing units. The relevant functions of the control circuit 250 can be implemented as hardware circuits, such as various logic blocks, modules and circuits in an integrated circuit, using hardware description languages (such as Verilog HDL or VHDL) or other suitable programming languages.

In software form and/or firmware form, the relevant functions of the control circuit 250 can be implemented as programming codes. For example, the control circuit 250 can be implemented using general programming languages (such as C, C++ or assembly language) or other suitable programming languages. The programming codes can be recorded/stored in a "non-transitory machine-readable storage medium". In some embodiments, the non-transitory machine-readable storage medium includes, for example, a semiconductor memory and/or a storage device. The electronic device (such as a CPU, a hardware controller, a microcontroller, a hardware processor or a microprocessor) can read and execute the programming code from the non-temporary machine-readable storage medium to implement the relevant functions of the control circuit 250.

In one embodiment, the data channel of the USB host side port 210 includes a differential pair eDp and eDn compliant with the eUSB2 specification, and the data channel of the USB device side port 220 includes a differential pair Dp and Dn compliant with the USB2 specification. In another embodiment, the data channel of the USB device side port 220 includes a differential pair eDp and eDn compliant with the eUSB2 specification, and the data channel of the USB host side port 210 includes a differential pair Dp and Dn compliant with the USB2 specification. In yet another embodiment, the data channel of each of the USB host side port 210 and the USB device side port 220 includes a differential pair Dp and Dn compliant with the USB2 specification. The input end of the repeater 230 is coupled to the data channel of the USB host side port 210 (e.g., differential pair eDp and eDn, or differential pair Dp and Dn). The output end of the repeater 230 is coupled to the data channel of the USB device side port 220 (e.g., differential pair eDp and eDn, or differential pair Dp and Dn). The input end of the repeater 240 is coupled to the data channel of the USB device side port 220. The output end of the repeater 240 is coupled to the data channel of the USB host side port 210.

The control circuit 250 detects the signal of the USB host side port 210 and the signal of the USB device side port 220 to dynamically determine the operation mode. In response to the operation mode entering the high-speed mode (HS) specified by the USB specification, the control circuit 250 controls the USB repeater device 200 to enter the waiting transaction-start mode. In the HS mode, the USB repeater device 200 is enabled to serve as a data transmission channel between the USB host side port 210 and the USB device side port 220. Further, in this embodiment, when the operation mode enters the high-speed mode specified by the USB specification, the control circuit 250 controls the USB repeater device 200 to enter the waiting transaction-start mode. Furthermore, the control circuit 250 controls the repeater 230 to operate in a standby state, and the control circuit 250 controls the repeater 240 to operate in a power-off state to save power. The operation mode is, for example, from a low-speed (LS) mode or a full-speed (FS) mode in accordance with the USB specification to a high-speed mode in accordance with the USB specification.

In one embodiment, in response to the operation mode being in the low-speed mode or full-speed mode specified by the USB specification, the control circuit 250 controls the repeaters 230 and 240 to operate in a power-off state. In the LS or FS mode, for example, a redriver (not shown) for the LS mode and the FS mode may be provided, which is enabled to serve as a data transmission channel between the USB host side port 210 and the USB device side port 220. This embodiment does not limit the specific implementation of the "redriver for the LS and FS modes". In the HS mode, the "redriver for the LS and FS modes" (not shown) is disabled to save power. In addition, this embodiment does not limit the setting of the "switching driver for LS and FS modes".

FIG3 is an operation flow chart of a USB repeater device in an embodiment of the present invention. The process shown in FIG3 operates in the L0 state (normal working state) of the link power management (LPM) specified by the USB specification. Please refer to FIG2 and FIG3. In step S310, the control circuit 250 detects the signal of the USB host side port 210 and the signal of the USB device side port 220 to dynamically determine the operation mode. The operation mode includes at least a waiting transaction-start mode and a waiting transaction-finish mode. The so-called "waiting transaction-start mode" means that the USB repeater device 200 detects the signal of the USB host side port 210 in real time to wait for the start of a transaction. The so-called "transaction" has been regulated in the USB protocol, so it will not be elaborated here. The so-called "wait for transaction end mode" means that the USB repeater device 200 detects the signal of the USB host side port 210 in real time to wait for the end of the current transaction.

In response to the operation mode being the transaction start waiting mode (the determination result of step S320 is "transaction start waiting mode"), the control circuit 250 controls the repeater 230 to operate in a standby state, and the control circuit 250 controls the repeater 240 to operate in a power-off state to save power (step S330). The output end of the repeater 230 in the standby state is in a high impedance (i.e., open circuit, or Hi-Z) state. The standby state is a power saving state in which the repeater 230 can be awakened within the time specified by the USB2 specification or the eUSB2 specification. The so-called "awakening" means that the repeater 230 enters the working state (active state) from the standby state. In response to a signal toggling (indicating the start of a new transaction transmission) at the USB host side port 210, the control circuit 250 changes the operation mode from the transaction start waiting mode to the transaction end waiting mode.

In response to the operation mode being the "wait for transaction end mode" (the judgment result of step S320 is "wait for transaction end mode"), the control circuit 250 controls the repeater 230 and the repeater 240 to transmit at least one transaction between the USB host port 210 and the USB device port 220 (step S340). Therefore, the USB repeater device 200 can operate normally. In response to the end of the current transaction transmission (the USB host port 210 and the USB device port 220 are both idle for a certain threshold time, and this threshold time is set based on the USB specification for transaction transmission), the control circuit 250 changes the operation mode from the "wait for transaction end mode" to the "wait for transaction start mode".

FIG4 is a schematic diagram of the operation mode of the USB repeater device of an embodiment of the present invention. Referring to FIG2 and FIG4, the control circuit 250 detects the signal of the USB host side port 210 to obtain the host side channel detection result. The control circuit 250 can also detect the signal of the USB device side port 220 to obtain the device side channel detection result. When both the USB host side port 210 and the USB device side port 220 are idle for a long time, the USB repeater device 200 remains in the transaction start waiting mode M41. In response to the host side channel detection result, the USB host side port 210 generates a signal toggling event S_in_HS_event, that is, the voltage level of the data channel of the USB host side port 210 switches, and the control circuit 250 changes the operation mode from the transaction start mode M41 to the transaction end mode M42. In a preferred embodiment, the detection of any signal or packet at the USB host side port 210 is defined as the occurrence of a signal toggling event. In other words, as long as the USB host side port 210 detects any signal or packet, the control circuit 250 changes the operation mode from the transaction start mode M41 to the transaction end mode M42 without any data or packet content determination. In response to the host side channel detection result and the device side channel detection result indicating that the USB host side port 210 and the USB device side port 220 have a long idle event HS&DS_idle_timeout_event, that is, the USB host side port 210 and the USB device side port 220 are both idle for a certain threshold time (this threshold time is set based on the USB specification for transaction transmission), the control circuit 250 changes the operation mode from the transaction end mode M42 to the transaction start mode M41.

The control circuit 250 controls the repeater 230 and the repeater 240 in the transaction termination mode to transmit transactions between the USB host port 210 and the USB device port 220, so that the USB repeater device 200 can operate normally. For example, in response to the host side channel detection result indicating that the voltage level of the data channel of the USB host port 210 switches, the control circuit 250 controls the repeater 230 to operate in an active state to transmit the packet of the USB host port 210 to the USB device port 220, and the control circuit 250 controls the repeater 240 to operate in a standby state. In response to the host side channel detection result indicating that the USB host side port 210 is idle, the control circuit 250 controls the repeater 230 to return from the working state to the standby state, and the control circuit 250 controls the repeater 240 to maintain the standby state. In response to the device side channel detection result indicating that the voltage level of the data channel of the USB device side port 220 switches, the control circuit 250 controls the repeater 240 to operate in the working state to transmit the packet of the USB device side port 220 to the USB host side port 210, and the control circuit 250 controls the repeater 230 to operate in the standby state. In response to the device side channel detection result indicating that the USB device side port 220 is idle, the control circuit 250 controls the repeater 240 to return from the working state to the standby state, and the control circuit 250 controls the repeater 230 to maintain the standby state.

In summary, the USB repeater device 200 can detect the signals of the USB host port 210 and the USB device port 220 in real time in a normal working state (e.g., the L0 state specified by the USB specification) to dynamically determine the operation mode. When the USB host port 210 and the USB device port 220 are both idle for a period of time or for a long time, the USB repeater device 200 enters the transaction start waiting mode M41. Each transaction starts with the USB host 110 sending the first packet to the USB device 130 in a unidirectional manner, and then the USB host 110 and the USB device 130 perform bidirectional transaction transmission. When the operation mode is the transaction start waiting mode M41, the USB repeater device 200 instantly detects whether the voltage level of the data channel of the USB host side port 210 switches to wait for the start of a transaction. During the waiting period for the "start of a transaction", it can be determined that the USB device 130 will not send a signal to the USB host 110, so the repeater 240 can operate in a power-off state to save power until the next transaction starts. Therefore, the USB repeater device 200 can reduce power consumption in a normal working state (such as the L0 state specified by the USB specification).

FIG. 5 is a schematic diagram of the operation mode of the USB repeater device of another embodiment of the present invention. The transaction start mode M41 and the transaction end mode M42 shown in FIG. 5 can refer to the relevant description of FIG. 4, so it is not repeated. In the embodiment shown in FIG. 5, the transaction end mode M42 includes a host-to-device direction mode M51, a two-way standby mode M52 and a device-to-host direction mode M53. Referring to FIG. 2 and FIG. 5, the control circuit 250 detects the signal of the USB host side port 210 to obtain the host side channel detection result. The control circuit 250 can also detect the signal of the USB device side port 220 to obtain the device side channel detection result. In response to the host side channel detection result indicating that the USB host side port 210 has a signal switching event S_in_HS_event, that is, the voltage level of the data channel of the USB host side port 210 has switched, the control circuit 250 changes the operation mode from the transaction start waiting mode M41 to the host to device direction mode M51.

In the host-to-device direction mode M51, the repeater 230 operates in an active state to transmit packets from the USB host side port 210 to the USB device side port 220, and the repeater 240 operates in a standby state. In response to the host side channel detection result indicating that the USB host side port 210 has an idle event HS_idle_event, that is, the USB host side port 210 is idle (the USB device side port 220 is also idle at this time), the control circuit 250 changes the operation mode from the host-to-device direction mode M51 to the bidirectional standby mode M52.

In the bidirectional standby mode M52, the repeater 230 and the repeater 240 are both maintained in the standby state. In response to the host side channel detection result indicating that the USB host side port 210 has a signal switching event S_in_HS_event, that is, the voltage level of the data channel of the USB host side port 210 has switched, the control circuit 250 changes the operation mode from the bidirectional standby mode M52 to the host to device direction mode M51. In response to the device side channel detection result indicating that a voltage switching event S_in_DS_event occurs in the data channel of the USB device side port 220, that is, a voltage level switching occurs in the data channel of the USB device side port 220, the control circuit 250 changes the operation mode from the bidirectional standby mode M52 to the device to host direction mode M53.

In the device-to-host direction mode M53, the repeater 240 operates in a working state to transmit packets from the USB device side port 220 to the USB host side port 210, and the repeater 230 operates in a standby state. In response to the device side channel detection result indicating that an idle event DS_idle_event occurs at the USB device side port 220, that is, the USB device side port 220 is idle (the USB host side port 210 is also idle at this time), the control circuit 250 changes the operation mode from the device-to-host direction mode M53 to the bidirectional standby mode M52. In response to the host side channel detection result and the device side channel detection result indicating that the USB host side port 210 and the USB device side port 220 have a long idle event HS&DS_idle_timeout_event, that is, the USB host side port 210 and the USB device side port 220 are both idle for a certain threshold time (this threshold time is set based on the USB specification for transaction transmission), the control circuit 250 changes the operation mode from the bidirectional standby mode M52 to the transaction start waiting mode M41.

FIG6 is a schematic circuit block diagram of a repeater 230, a repeater 240, and a control circuit 250 of an embodiment of the present invention. The repeater 230, the repeater 240, and the control circuit 250 shown in FIG6 can be used as one of the many implementation examples of the repeater 230, the repeater 240, and the control circuit 250 shown in FIG2. The USB host side port 210, the USB device side port 220, the repeater 230, the repeater 240, and the control circuit 250 shown in FIG6 can refer to the relevant description of FIG2, so it is not repeated.

In the embodiment shown in FIG. 6 , the control circuit 250 includes a signal detector 251, a signal detector 252, and a controller 253. The signal detector 251 is used to detect the voltage level switching of the data channel of the USB host side port 210. The controller 253 is coupled to the signal detector 251 to receive the host side channel detection result. The signal detector 252 is used to detect the voltage level switching of the data channel of the USB device side port 220. The controller 253 is coupled to the signal detector 252 to receive the device side channel detection result. The relevant functions of the controller 253 can be implemented in various logic blocks, modules and circuits in a hardware controller, microcontroller, hardware processor, microprocessor, ASIC, DSP, FPGA, CPU and/or other processing units. The relevant functions of the controller 253 can be implemented as hardware circuits, such as various logic blocks, modules and circuits in integrated circuits using hardware description languages (such as Verilog HDL or VHDL) or other suitable programming languages.

In response to the host side channel detection result of the signal detector 251 indicating that the voltage level of the data channel of the USB host side port 210 switches, the controller 253 changes the operation mode from the transaction start mode M41 to the transaction end mode M42. In response to the host side channel detection result of the signal detector 251 and the device side channel detection result of the signal detector 252 indicating that both the USB host side port 210 and the USB device side port 220 are idle for a certain threshold time (this threshold time is set based on the USB specification for transaction transmission), the controller 253 changes the operation mode from the transaction end mode M42 to the transaction start mode M41.

For example, referring to FIG. 5 and FIG. 6 , in response to a signal switching event S_in_HS_event occurring at the USB host side port 210, i.e., a voltage level switching occurs at the data channel of the USB host side port 210, the controller 253 changes the operation mode from the transaction start waiting mode M41 to the host-to-device direction mode M51. In the host-to-device direction mode M51, the repeater 230 operates in a working state and the repeater 240 operates in a standby state. In response to the occurrence of an idle event HS_idle_event at the USB host side port 210, i.e., the USB host side port 210 is idle (the USB device side port 220 is also idle at this time), the controller 253 changes the operation mode from the host-to-device direction mode M51 to the bidirectional standby mode M52. In the bidirectional standby mode M52, both the repeater 230 and the repeater 240 remain in the standby state. In response to the occurrence of a signal switching event S_in_HS_event at the USB host side port 210, i.e., the voltage level switching occurs in the data channel of the USB host side port 210, the controller 253 changes the operation mode from the bidirectional standby mode M52 to the host-to-device direction mode M51. In response to the signal switching event S_in_DS_event occurring at the USB device side port 220, i.e., the voltage level switching occurring at the data channel of the USB device side port 220, the controller 253 changes the operation mode from the bidirectional standby mode M52 to the device-to-host direction mode M53. In the device-to-host direction mode M53, the repeater 240 operates in a working state, and the repeater 230 operates in a standby state. In response to the idle event DS_idle_event occurring at the USB device side port 220, i.e., the USB device side port 220 is idle (the USB host side port 210 is also idle at this time), the controller 253 changes the operation mode from the device-to-host direction mode M53 to the bidirectional standby mode M52. In response to the long idle event HS&DS_idle_timeout_event occurring in the USB host port 210 and the USB device port 220, that is, the USB host port 210 and the USB device port 220 are both idle for a certain threshold time (this threshold time is set based on the USB specification for transaction transmission), the controller 253 changes the operation mode from the bidirectional standby mode M52 to the transaction start waiting mode M41.

In the embodiment shown in FIG6 , the repeater 230 includes an equalizer 231 and a driver 232. The input end of the equalizer 231 is coupled to the input end of the repeater 230, that is, coupled to the data channel of the USB host side port 210. The input end of the driver 232 is coupled to the output end of the equalizer 231. The output end of the driver 232 is coupled to the output end of the repeater 230, that is, coupled to the data channel of the USB device side port 220. In response to the repeater 230 operating in the working state, the controller 253 controls the equalizer 231 and the driver 232 to operate in the normal power-on state to transmit the packet of the USB host side port 210 to the USB device side port 220. In response to the repeater 230 operating in the standby state, the controller 253 controls the output end of the driver 232 to be in a high impedance (or Hi-Z) state (at this time, the equalizer 231 can remain in the working state). The driver 232 can return to the working state from the standby state immediately within the time specified by the USB2 specification or the eUSB2 specification (for example, 8ns).

In the embodiment shown in FIG. 6 , the repeater 240 includes an equalizer 241 and a driver 242. The input end of the equalizer 241 is coupled to the input end of the repeater 240, that is, coupled to the data channel of the USB device side port 220. The input end of the driver 242 is coupled to the output end of the equalizer 241. The output end of the driver 242 is coupled to the output end of the repeater 240, that is, coupled to the data channel of the USB host side port 210. In response to the repeater 240 operating in the working state, the controller 253 controls the equalizer 241 and the driver 242 to operate in the normal power-on state to transmit the packet of the USB device side port 220 to the USB host side port 210. In response to the repeater 240 operating in the standby state, the controller 253 controls the output end of the driver 242 to be in a high impedance (or Hi-Z) state (at this time, the equalizer 241 can remain in the working state). The driver 242 can return to the working state from the standby state immediately within the time specified by the USB2 specification or the eUSB2 specification (for example, 8ns). In some application cases, in response to the operation mode being the transaction start mode M41, the controller 253 controls the equalizer 241 to operate in the normal power-on state, and the controller 253 controls the driver 242 to operate in the power-off state. In other application cases, in response to the operation mode being the transaction start mode M41, the controller 253 controls both the equalizer 241 and the driver 242 to operate in the power-off state.

Although the novel creation has been disclosed as above by way of embodiments, it is not intended to limit the novel creation. Anyone with ordinary knowledge in the relevant technical field may make some changes and modifications within the spirit and scope of the novel creation. Therefore, the protection scope of the novel creation shall be subject to the scope of the patent application attached hereto.

200:USB repeater device

210: USB host port

220: USB device port

230, 240: Repeater

250: Control circuit

Claims (11)

A USB repeater device comprises: a USB host side port; a USB device side port; a first repeater having an input end coupled to the USB host side port, wherein an output end of the first repeater is coupled to the USB device side port; a second repeater having an input end coupled to the USB device side port, wherein an output end of the second repeater is coupled to the USB host side port; and a control circuit coupled to the USB host side port and the USB device side port to detect the USB host. The signal of the USB host side port and the signal of the USB device side port dynamically determine an operation mode, wherein, in response to the operation mode being a transaction start mode, the control circuit controls the first repeater to operate in a standby state, and the control circuit controls the second repeater to operate in a power-off state to save power; and in response to the operation mode being a transaction end mode, the control circuit controls the first repeater and the second repeater to transmit at least one transaction between the USB host side port and the USB device side port. A USB repeater device as described in claim 1, wherein the data channel of one of the USB host side port and the USB device side port includes a differential pair eDp and eDn that complies with an embedded USB2 specification, and the data channel of the other of the USB host side port and the USB device side port includes a differential pair Dp and Dn that complies with a USB2 specification. A USB repeater device as described in claim 1, wherein the data channel of each of the USB host side port and the USB device side port includes a differential pair Dp and Dn that complies with a USB2 specification. A USB repeater device as described in claim 1, wherein the standby state is a power saving state in which the first repeater can be awakened within a time specified by a USB2 specification or an embedded USB2 specification, and the output end of the first repeater in the standby state is in a high impedance state. A USB repeater device as claimed in claim 1, wherein the control circuit detects the signal of the USB host side port to obtain a host side channel detection result, and the control circuit detects the signal of the USB device side port to obtain a device side channel detection result, and in response to the host side channel detection result indicating that a voltage level switching occurs in the data channel of the USB host side port In response to the host-side channel detection result and the device-side channel detection result indicating that both the USB host-side port and the USB device-side port have been idle for a threshold time, the control circuit changes the operation mode from the transaction end mode to the transaction start mode. A USB repeater device as described in claim 5, wherein the voltage level switching of the USB host side port refers to a signal switching event occurring at the USB host side port; and the USB host side port and the USB device side port are both idle for the threshold time, which refers to a long-term idle event occurring at the USB host side port and the USB device side port. A USB repeater device as described in claim 5, wherein in the transaction termination modes: in response to the host-side channel detection result indicating that a voltage level switch occurs in the data channel of the USB host side port, the control circuit controls the first repeater to operate in a working state to transmit at least one packet of the USB host side port to the USB device side port, and the control circuit controls the second repeater to operate in the standby state; in response to the host-side channel detection result indicating that the USB host side port is idle, the control circuit controls the first repeater to recover from the working state to the standby state, and the control circuit controls the The second repeater is maintained in the standby state; in response to the device-side channel detection result indicating that the data channel of the USB device side port has a voltage level switch, the control circuit controls the second repeater to operate in the working state to transmit at least one packet of the USB device side port to the USB host side port, and the control circuit controls the first repeater to operate in the standby state; and in response to the device-side channel detection result indicating that the USB device side port is idle, the control circuit controls the second repeater to recover from the working state to the standby state, and the control circuit controls the first repeater to maintain in the standby state. A USB repeater device as described in claim 1, wherein the control circuit detects the signal of the USB host side port to obtain a host side channel detection result, the control circuit detects the signal of the USB device side port to obtain a device side channel detection result, the transaction termination modes include a host to device direction mode, a device to host direction mode and a bidirectional standby mode, and in response to the host side channel detection result indicating that a voltage level switch occurs in the data channel of the USB host side port, the control circuit changes the operation mode from the transaction start mode to the device side channel detection result. the host-to-device direction mode, wherein in the host-to-device direction mode, the first repeater operates in a working state to transmit at least one packet of the USB host side port to the USB device side port, and the second repeater operates in the standby state; in response to the host side channel detection result indicating that the USB host side port is idle, the control circuit changes the operation mode from the host-to-device direction mode to the bidirectional standby mode, wherein in the bidirectional standby mode, the first repeater and the second repeater both remain in the standby state; In response to the host-side channel detection result indicating that the voltage level of the data channel of the USB host side port switches, the control circuit changes the operation mode from the bidirectional standby mode to the host-to-device direction mode; in response to the device-side channel detection result indicating that the voltage level of the data channel of the USB device side port switches, the control circuit changes the operation mode from the bidirectional standby mode to the device-to-host direction mode, wherein in the device-to-host direction mode, the second repeater operates in the working state to switch the voltage level of the USB device side port to the host-to-device direction mode. At least one packet is transmitted to the USB host side port, and the first repeater operates in the standby state; in response to the device side channel detection result indicating that the USB device side port is idle, the control circuit changes the operation mode from the device-to-host direction mode to the bidirectional standby mode; and in response to the host side channel detection result and the device side channel detection result indicating that both the USB host side port and the USB device side port are idle for a threshold time, the control circuit changes the operation mode from the bidirectional standby mode to the transaction start mode. A USB repeater device as described in claim 1, wherein the second repeater includes: an equalizer having an input terminal coupled to the input terminal of the second repeater; and a driver having an input terminal coupled to an output terminal of the equalizer, wherein an output terminal of the driver is coupled to the output terminal of the second repeater, and in response to the operating mode being the transaction start mode, the control circuit controls at least one of the equalizer and the driver to operate in the power-off state. The USB repeater device as claimed in claim 1, wherein the control circuit comprises: a first signal detector coupled to the USB host side port to detect a voltage level switch of a data channel of the USB host side port; a second signal detector coupled to the USB device side port to detect a voltage level switch of a data channel of the USB device side port; and a controller coupled to the first signal detector to receive a host side channel detection result, and coupled to the second signal detector to receive a device side channel detection result. The controller is configured to detect the side channel detection result of the USB host side port, wherein, in response to the host side channel detection result indicating that a voltage level switch occurs in a data channel of the USB host side port, the controller changes the operation mode from the transaction start mode to the transaction end mode; and in response to the host side channel detection result and the device side channel detection result indicating that both the USB host side port and the USB device side port are idle for a threshold time, the controller changes the operation mode from the transaction end mode to the transaction start mode. A USB repeater device as described in claim 1, wherein, in response to the operating mode entering a low-speed mode or a full-speed mode in accordance with a USB specification, the control circuit controls the first repeater and the second repeater to operate in the power-off state; and in response to the operating mode entering a high-speed mode in accordance with the USB specification from the low-speed mode or the full-speed mode, the control circuit controls the USB repeater device to enter the transaction start modes.

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