So to SEND an AVR command to the EDBG, it is wrapped as:


Large packets must be chopped up according to the HID interface’s REPORT_SIZE. The fragment number envelope field is two 4-bit nibbles indicating a "packet m of n packets" relationship:

(packet_number << 4) | total_number_of_packets

Each SEND fragment responds with:


This is not to be confused with the AVR_RSP, which is the response to the command itself, which is detailed next.