2.1 EDBG Interface Overview

The Embedded Debugger (EDBG) implements a composite USB device consisting of three interfaces:

  • Programming and debugging interface (HID)

  • CDC Virtual COM port

  • Atmel Data Gateway Interface

The programming and debugging interface is an implementation of the CMSIS-DAP interface defined by Keil®. CMSIS-DAP supports access to any ARM® Coresight Debug Access Port. CMSIS-DAP supports a set of "vendor" commands, which are used by EDBG for accessing special functions not natively supported by CMSIS-DAP, as well as for debugging and programming AVR® device families.

The CDC Virtual COM port implementation provides a simple link between a COM port registered on the host PC and a RX-TX pin pair on the EDBG. This pair is connected to a UART pin pair on the board on which the EDBG is embedded.

The DGI is a bidirectional interface for streaming data to and from the EDBG. It is a custom interface with input and output BULK endpoints. The DGI protocol is specified in a separate document.

Note: mEDBG is a scaled-down EDBG implementation and does not support the DGI.
Note: EDBGC does not include DGI support.