As a stand alone processor the F21 already uses lower power then the Dragon ball, ARM processor or MIPS cores such as the NEC VR4181.
The F21 is also much lower cost, and  run over 100x faster then a typical Motorola Dragon Ball(2.7 Mips).
Enumera plans to release a version of this with out the video and some internal DRAM as a single chip MP3 player.
Co-processor dedicated to audio or I/O processing can be
easily added.