Machine-translated by Google. Questions are authored in English.
Top

Discussion

In USB the roles are asymmetric because

  • A.only the device may detect an error
  • B.the host initiates every transfer
  • C.the device supplies the bus power
  • D.the host and device use different connectors on the same cable

Answer: B

A device never speaks until polled, which is why two devices cannot be connected together and why a microcontroller acting as a host needs quite different software from one acting as a device. On-the-go negotiation exists precisely to swap the roles.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.