Hello Ralf,

Cygnal sells development kits that come with a serial adapter for the JTAG interface and an IDE for programming and debugging. The adapter is also available seperately. Check the 'Development Tools' section on their website for more details. The IDE runs under Windows, I don't know about Linux support... Try and ask them; they have excellent technical support.

As I said earlier, it is possible, even quite easy, to reprogram the FLASH over the serial interface. The memory in the Cygnal devices is segmented into 512 byte blocks which can be erased seperately, so you can for example put your bootloader code in the upper 2 or 3 segments and (re)program the lower segments from there.

Regards,
Rob.