Appendix BGlossary of USB Terms

ACK:

Handshake packet indicating a positive acknowledgement between devices, or a host and device on the Universal Serial Bus.

Active Device:

A device that is not in the suspended state and is powered on.

Asynchronous Data:

Data that is sent across the Universal Serial Bus without regard to timing requirements; the opposite of isochronous.

Babble:

Persistent data on the bus that is not expected by any device or the host.

Bandwidth:

The amount of data that can be transmitted over the bus in a given amount of time; this is usually expressed in bits per second (bps).

Bit:

A single element of data within the computer (or on the bus) that is either a 1 or a 0 (indicating high voltage or low). There are ...

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