PORTS Forum

Ports and Interfaces => USB => Topic started by: tkafafi on March 07, 2012, 09:30:22 pm

Title: Is it possble to USB host and device connectors to share the same port ?
Post by: tkafafi on March 07, 2012, 09:30:22 pm

The situation I'm asking about is if a usb port on an intergrated chip can be connected to an A connector and a B connector together. But only one connector would be active at a given time depending on whether the integrate chip port is operating in host or device mode.

Essentaill trying to implement something like On-The-Go mode but with standard A and B connectors instead of the microAB connector ?

Or maybe the way to do this is to implement an OTG port with microAB connector , then have an A or B port adaptor. Is there such an adaptor ?

Thanks

Title: Re: Is it possble to USB host and device connectors to share the same port ?
Post by: Jan Axelson on March 07, 2012, 10:16:30 pm

A system can have both a host and device port. They can be active at the same time. If for some reason you wanted only one to be active at a time, I suppose you could implement that in firmware with an error message if someone attaches something to both ports.

A micro-AB connector doesn't need an adapter because you can attach either a micro-A or a micro-B plug. The OTG spec defines a micro-A/standard-A adapter. But the micro-AB connector is specified for OTG systems only so you would need to meet the OTG requirements.

Jan

Title: Re: Is it possble to USB host and device connectors to share the same port ?
Post by: Pat Crowe on March 08, 2012, 11:19:00 am

It sounded to me as though the OP wants to connect one port on the chip to both connectors at the same time. If so, this is a Bad Idea.