US 12,216,602 B2
Methods and apparatus to detect L2 entry and reset in universal serial bus repeaters
Anant Kamath, Bangalore (IN); Suzanne M. Vining, Plano, TX (US); Rakesh Hariharan, Bangalore (IN); Mark Wentroble, Plano, TX (US); Christopher Rodrigues, Bangalore (IN); and Prajwala P, Cambridge (GB)
Assigned to Texas Instruments Incorporated, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Jan. 21, 2022, as Appl. No. 17/581,202.
Prior Publication US 2023/0237002 A1, Jul. 27, 2023
Int. Cl. G06F 13/38 (2006.01); G06F 13/40 (2006.01)
CPC G06F 13/385 (2013.01) [G06F 13/4068 (2013.01); G06F 2213/0042 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A system comprising a USB repeater, the USB repeater including:
an upstream circuit;
a downstream circuit;
a controller coupled to the upstream circuit and the downstream circuit; and
wherein the USB repeater is configured to:
replicate a transmission to the upstream circuit on the downstream circuit;
determine whether a duration without USB communications between the upstream circuit and the downstream circuit is greater than a threshold;
in response to determining the whether the duration without USB communication is greater than the threshold, the controller enables a high-speed termination detection circuit;
in response to the high-speed termination detection circuit being enabled, the high-speed termination detection circuit compares an output of the upstream circuit to a reference;
in response to comparing the output of the upstream circuit to the reference, the high-speed termination detection circuit determines whether a state of a device coupled to the upstream circuit is a reset state or a suspend state; and
in response to determining the state of the device, the controller sets the downstream circuit to replicate the state of the device.