The b16 Processor is a minimalistic stack processor, inspired by Chuck Moore's recent work. The original incarnation is 16 bit, byte addressed. There are 32 instructions, each is 5 bits. Three and a bit (literally!) are packed into a 16 bit word (bundle). The first slot in the bundle can only be a nop or a call.

The b16 is intented as small microcontroller, and suitable if you need more processing power than a 8051, but less die space (or gate count) and power consumption.

You can find more documentation in the Forth Tagung 2002 presentation (131k), or the English translation (2M).

You can download the Sources (851k) (sig), the evaluation board schematics (74k) and the Gerber data (481k) of the evaluation board.

There's now a USB interface (not fully tested, undocumented), minimalistic interrupts (tested, somewhat documented), and a small test bench to integrate all that stuff. I plan to also add an Ethernet MAC, and build a new Cyclone-based board with both USB and Ethernet functionality.

The small version of the b16 has an even further reduced instruction set, and fits into half the size.

You can find more documentation in the EuroForth 2004 proceeding (131k).

Yu can download the Sources (143k) here.