The Universal Serial Bus (USB) is an industry standard serial
interface designed to connect computers to their peripherals.
Devices such as keyboards, mice, joysticks, scanners, printers,
and others can all benefit from the connectivity provided
by USB. This application note describes how to design a USB
keyboard and PS/2 mouse combination device using the
Cypress Semiconductor single-chip CY7C63413 USB microcontroller.
The PS/2 mouse is a widely used, low-cost pointing
device found in computers today. By implementing a legacy
PS/2 interface on the CY7C63413 USB microcontroller, originally
targeted for USB keyboards, we provide a simple,
low-cost solution for keyboard and mouse combination devices.
This document starts with the basic operations of a USB
keyboard and PS/2 mouse transfer protocol, followed by an
introduction to the CY7C63413 USB controller. A schematic
of the USB keyboard and PS/2 mouse combination device
with its connection details can be found in the Hardware Implementation
Section.