Welcome to ECO32!

The ECO32 project was inspired by Jan Gray's three-part article "Building a RISC System in an FPGA" which appeared in the March through May 2000 issues of "Circuit Cellar - The Magazine for Computer Applications". We are building a similar system with a lot of enhancements.

ECO32 is a simple, fast 32-bit processor that runs C code, currently without floating point operations. We want to execute some flavour of UNIX on it, so it has got two operating modes (kernel/user) and a memory management unit (paging with TLB support). The processor was first simulated at the instruction set level, then at the HDL level, and has finally been implemented in an FPGA.

We have an ANSI-C compiler (LCC) and an assembler/linker toolchain available, as well as an unpolished port of the UNIX 7th Edition kernel. We are working on a GCC back-end, a NetBSD port, and a Linux port.

NOTE: The project has been transferred to GitHub:


If you have any further questions (or are eager to contribute to this project :-), don't hesitate to contact the ECO32 team by email to


Hellwig Geisse