UART Emulation

I am using an Atmel AT89C5132 and am connecting it through the USB
bootloader to my computer. But I want to interpret the data as a Serial
input.

I have heard you can use UART emulation (Communication Device Class).
Where you can set the USB Class with a virtual COM port in Windows, and
then can send/receive data using the Windows normal UART communication. 
Basically emulate the COM port using a USB connection. 

My question is does anybody know how to do this or where I could find some
code for this.

> I have heard you can use UART emulation (Communication Device Class).
> Where you can set the USB Class with a virtual COM port in Windows, and
> then can send/receive data using the Windows normal UART communication.
> Basically emulate the COM port using a USB connection.
>
> My question is does anybody know how to do this or where I could find some
> code for this.

The USB CDC interface is probably the most common freebies that one can 
obtain from the device vendor.  I haven't seen a microcontroller with USB 
yet that didn't have free virtual COM port source code available.  Check 
your chip vendor's web site for free code.  If you can't find it, search the 
web in general.  If that doesn't work, search for competing vendors 
implementations and try porting it.  Porting will be a lot of work but it's 
easier than writing it from scratch.

JJS