The filename field indicates the name of the file to read or write.  The format field is optional and contains the format of the file to read or write.  Format can be one of:

                   i    Intel Hex

                   s    Motorola S-record

                   r    raw binary; little-endian byte order, in the case of the flash ROM data

                   e    ELF (Executable and Linkable Format)

                   m    immediate; actual byte values specified on the command line, separated by commas or spaces.  This is good for programming fuse bytes without having to create a single-byte file or enter terminal mode.

                   a    auto detect; valid for input only, and only if the input is not provided at stdin.

                   d    decimal; this and the following formats are only valid on output.  They generate one line of output for the respective memory section, forming a comma-separated list of the values.  This can be particularly useful for sub‐
                        sequent processing, like for fuse bit settings.

                   h    hexadecimal; each value will get the string 0x prepended.

                   o    octal; each value will get a 0 prepended unless it is less than 8 in which case it gets no prefix.

                   b    binary; each value will get the string 0b prepended.

                   The default is to use auto detection for input files, and raw binary format for output files.  Note that if filename contains a colon, the format field is no longer optional since the filename part following the colon would
                   otherwise be misinterpreted as format.

                   When reading any kind of flash memory area (including the various sub-areas in Xmega devices), the resulting output file will be truncated to not contain trailing 0xFF bytes which indicate unprogrammed (erased) memory.  Thus,
                   if the entire memory is unprogrammed, this will result in an output file that has no contents at all.