Microchip Technology Incorporated
Automatic USB Host Detection and Port Configuration

Abstract:

A universal serial bus (USB) hub includes detection circuits for a D- and a D+ connection of a USB port and a control circuit. The control circuit is configured to disable, detection circuits, respective impedances. After disabling the respective impedances, the USB hub is further configured to detect, at the detection circuits, respective values from the D+ connection and the D- connection. The USB hub is further configured to, based upon the respective values, switch the USB port between a device port configuration and a host port configuration.