PS/2 to USB Mouse Example     		  	Rev. -    30 August 2001

Summary:

This firmware translates a PS/2 mouse to a USB mouse.  The translator 
firmware is entirely interrupt driven (with the exception of sending the 
data via USB to the host.)  An interrupt is generated when the PS/2 start 
bit is received, at which time the firmware will begin its receive routine. 
In addition to this interrupt, every 168ms a timer overflow interrupts the 
main program and implements one state of the mouse state machine.  This 
state machine handles sending bytes to and translating bytes received from 
the PS/2 mouse automatically.  All of this is done in the background while 
the main program runs in the foreground.  The only operation that the main 
program implements is sending mouse data to the PC via USB.