Nanocontrollers for biomedical applications.

Several semiconductor companies now manufacture low cost single-chip microcontrollers in dual inline packages having twenty or fewer pins. The controllers are field programmable by means of inexpensive development boards linked to personal computers. These processors were designed with a minimalist philosophy which provide them with only a few dozen bytes of on-chip RAM, hundreds of bytes of PROM, a parallel port, a counter/timer, and reduced instruction sets. The better-equipped members of this class may have special on-chip hardware, such as analog-to-digital input, pulse-width modulation output and a serial port. Most must be programmed in assembler, although some support BASIC, "C" or other languages. Their tiny size, design simplicity and operational single-mindedness earn them the nickname "nanocontrollers". Despite meager resources, these controllers can be successfully employed in a variety of biomedical applications. Such uses include: consolidation of multi-chip "glue logic" circuitry; functioning as subsystem elements in complex designs; serving as device drivers or protocol converters; and forming the building blocks of hypercube processor arrays or artificial neural networks. This paper describes the general capabilities, special features, and some application examples of "nanocontroller" technology.