Introduction
The Human Interface Device (HID) class specification allows designers to create USB-based devices and applications without the need for custom driver development. Their high levels of on-chip integration and robust USB interface make Silicon Laboratories microcontrollers ideal devices for HID designs.

About this Document
This application note assumes that the reader has a basic understanding of the USB specification, including some knowledge of endpoints, descriptors, and transfer protocols. This document concentrates on highlighting the benefits of designing with HID and techniques for creating and optimizing HID-based systems that use Silicon Laboratories microcontrollers.
This document includes the following:

■ Discussion on HID
■ A firmware template that can be used as a starting point for HID device firmware
■ Description of the HID object class that can be used by host applications to communicate with HID devices
■ Explanation of two example HID firmware systems implemented by modifying the Template Firmware
■ Firmware source for each HID example discussed in the text
■ Example code for host-side application software