USB dynamic service switch for dual processor architecture

A Universal Serial Bus device comprising:

• a first processor configured as a Universal Serial Bus device to provide a first set of services to an external host;
• and
• a second processor, coupled to said first processor as a Universal Serial Bus host and coupled to a Universal Serial Bus device connector suitable for connection to said external host, configured to provide a second set of services to said external host, and configured to pass service data bi-directionally between said first processor and said external host for said first set of services,
• wherein said second processor is further configured to respond to a set configuration request from said external host by comparing configuration sets of said first processor and said second processor, transmitting a set interface request to said first processor if said configuration sets are different, and transmitting a configuration request to said first processor if said configuration sets are identical.

A method of Universal Serial Bus enumeration by a Universal Serial Bus device having a first processor and a second processor comprising:

• connecting a host to said Universal Serial Bus device;
• receiving, from said host, a set configuration request;
• determining that said first processor and said second processor have the same configuration sets;
• transmitting, by said second processor, a set configuration request to said first processor for the configuration of said second processor;
• and
• closing, by said first processor, a logical switch to connect services to said second processor in response to said configuration request.

A method of Universal Serial Bus enumeration by a Universal Serial Bus device having a first processor and a second processor comprising:

• connecting a host to said Universal Serial Bus device;
• receiving from said host a set configuration request;
• determining that said first processor and said second processor have different configuration sets;
• transmitting by said second processor at least one set interface request to said first processor;
• and
• closing, by said first processor, at least one logical switch to connect at least one service to said second processor in response to said at least one set interface request.