Atmel Evaluation Board AT32UC3C-EK AT32UC3C-EK Data Sheet
Product codes
AT32UC3C-EK
AVR32919
32151A-AVR-09/10
4.7 USB Virtual Com Port Interface
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.
Serial Com Port communication capabilities to the Atmel AT32UC3C0512C through
the on-board Atmel AT32UC3B1256 device.
4.7.1 Overview
Figure 4-16. Atmel AT32UC3C-EK USB Virtual Com Port Interface Logical View
AT32UC3
B1256
USART2
USB
JTAG
(J31)
USB Virtual Com Port
USB VCP
(J27)
The USB Virtual Com Port interface provides two features to the Atmel AT32UC3C-
EK kit:
EK kit:
• USB communication,
• Power supply (see section 4.1 for a description of that feature).
The USB controller is the Atmel AT32UC3B1256.
• 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.
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.
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.
pins.