Universal serial bus repeater with improved remote wake capability

A method comprising:

• driving data in a first direction from a second device to a first device;
• driving a first signal line of a pair of signal lines between the first device and a first-device-side transceiver of a repeater to a logic low state, and driving a second signal line of the pair of signal lines to a logic high state;
• when the first signal line is driven to the logic low state and the second signal line is driven to the logic high state, disabling a first pull-up resistive element coupled between a power supply voltage and the first signal line and enabling a second pull-up resistive element coupled between the power supply voltage and the second signal line;
• changing data flow from the first direction to a second direction from the first device to the second device;
• detecting a single-ended zero (SE0) state;
• and
• enabling the first pull-up resistive element and disabling the second pull-up resistive element.

A repeater comprising:

• a transceiver including a detection circuit, the detection circuit comprising:
• a first current source;
• a first comparator having first and second inputs and an output, the first input coupled to a first signal line of a pair of signal lines and to the first current source, the second input configured to receive a reference signal, and the output configured to output a first detection signal, the transceiver configured to enable the first current source and the first comparator in response to a wake up signal;
• a second current source;
• and
• a second comparator having first and second inputs and an output, the first input coupled to a second signal line of the pair of signal lines and to the second current source, the second input configured to receive the reference signal, and the output configured to output a second detection signal.

A repeater comprising:

• a first assembly including a first pull-up resistor and a first switch, the first assembly coupled to a first signal line of a pair of signal lines, the first switch moveable between an open position in which the first pull-up resistor is disconnected from the first signal line and a closed position in which the first pull-up resistor is connected to the first signal line;
• a current source coupled to the first signal line, wherein the current source is configured to be enabled and the first switch is configured to be moved to the open position based on a state of the first signal line and a second signal line of the pair of signal lines;
• a second assembly including a second pull-up resistor and a second switch, the second assembly coupled to the second signal line of the pair of signal lines, the second switch moveable between an open position in which the second pull-up resistor is disconnected from the second signal line and a closed position in which the second pull-up resistor is connected to the second signal line;
• and
• a transmitter coupled to the first and second signal lines and further including an enable input configured to receive an enable signal based on positions of the first and second switches.

A method comprising:

• driving Remote Wake signaling by a second device including driving a K state to exit from a sleep or suspend state;
• in response to the K state, enabling a current source coupled to a signal line of a USB repeater;
• detecting, using a comparator coupled to the signal line of the USB repeater, when a first device starts driving Resume signaling;
• and
• changing data flow from a first direction from the second device to the first device to a second direction from the first device to the second device, in response to the detecting.