Atmel Evaluation Board AT32UC3C-EK AT32UC3C-EK Data Sheet

 

32151A-AVR-09/10 

The USB Virtual Com Port interface on the Atmel AT32UC3C-EK offers USB CDC 
Serial Com Port communication capabilities to the Atmel AT32UC3C0512C through 
the on-board Atmel AT32UC3B1256 device. 

Figure 4-16. Atmel AT32UC3C-EK USB Virtual Com Port Interface Logical View 

The USB Virtual Com Port interface provides two features to the Atmel AT32UC3C-
EK kit: 

• USB communication, 
•  Power supply (see section 4.1 for a description of that feature). 
The USB controller is the Atmel AT32UC3B1256. 

The AT32UC3B1256 comes pre-loaded with several firmwares: 

•  A USB DFU Bootloader (accessible upon power-up when the J28 header is closed 

(see Figure 4-16 for the location of the J31 header)) to re-program the 
AT32UC3B1256. 

•  A USB CDC-USART bridge (aka a USB CDC Virtual Com Port) where every data 

character received from USB is sent to the Atmel AT32UC3C0512C’s USART2 and 
every character received from the AT32UC3C0512C’s USART2 is sent to USB. 

The source code of these firmwares is available in the ASF (ref. section 3.4.6). 

Warning note: programming the AT32UC3B1256 will overwrite the default firmware. 

The AT32UC3B1256 can be debugged through the JTAG interface J31 header. 

The AT32UC3B1256 is connected to the AT32UC3C0512C’s USART2 TX and RX 
pins.