What example code does Maxim Integrated supply for the MAX3420E?

You can find example C code for implementing a HID application on the Maxim website at USB Enumeration Code (and More) for the MAX3420E. This example code emulates a PC keyboard, which types a text string into any Windows application that accepts text (e.g., Notepad) whenever a pushbutton is pressed. By conforming to the standard HID class, the application runs without a custom Windows driver. Regardless of your target application, most of this example code is USB "boilerplate" that can be used as a starting point for your code.