AN57294 - USB 101: An Introduction to Universal Serial Bus 2.0 | Cypress Semiconductor
AN57294 - USB 101: An Introduction to Universal Serial Bus 2.0
AN57294 is a foundation for understanding the USB protocol, specifically focusing on the USB 2.0 specification. It is intended for those who are new to using USB in embedded designs, and for those who need to use and understand more advanced Cypress application notes.
USB is an interface that connects a device to a computer. With this connection, the computer sends or retrieves data from the device. USB gives developers a standard interface to use in many different types of applications. A USB device is easy to connect and use because of a systematic design process.