USB is likely the most successful communication interface in the history of computer systems, and is the de-facto standard for connecting computer peripherals. Micri m's C/USB-Device is a USB device stack designed specifically for embedded systems. Built from the ground up with Micri m's quality, scalability and reliability, it has gone through a rigorous validation process to comply with the USB 2.0 specification. The first part of this book describes the inner-workings of USB using Micri m's C/USB-Device stack as a reference. The second part demonstrates how the Renesas YRDKRX63N Demonstration Kit (sold separately) and Micri m's C/USB-Device stack can be used as the foundation to build a USB device that relies on a combination of proven hardware and software platforms. Renesas' ultra-low-power RX63N MCU is at the core of the YRDKRX63N board, which incorporates communication functions such as USB 2.0 full-speed (host or device) among others. The examples featured in this book include USB devices with the most basic functionality that will allow you to understand the USB concepts covered in the first part of the book and at the same time, they provide a framework to quickly build devices such as: - USB-to-serial adapter (Communications Device Class) - Mouse or keyboard (Human Interface Device Class) - Removable storage device (Mass Storage Class) - USB medical device (Personal Healthcare Device Class) - Custom device (Vendor Class)