XSOC Circuit Cellar Article Series

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Jan Gray's article series on XSOC, Building a RISC System in an FPGA, ran in the March, April, and May 2000 issues of Circuit Cellar magazine. (Preceding links are to Adobe Acrobat versions of the articles.)

[updated: 03/07/01:]
Here are the original draft versions of the articles: xsoc-series-drafts.pdf. These drafts have better schematics, and a more conversational style.

The articles present the design and implemention of the XSOC System-on-a-Chip, including the new xr16 pipelined RISC processor core, on-chip bus, bus/memory controller, and integrated peripherals (parallel port, bilevel VGA controller), all in a single Xilinx XC4005XL FPGA, and also describe a port of the lcc4.1 retargetable C compiler, an assembler, simulator, and demos.

Theme:

"Several companies sell FPGA CPU cores, but most are synthesized implementations of existing instruction sets, filling huge, expensive FPGAs, and are too slow and too costly for production use. These cores are marketed as ASIC prototyping platforms."

"In contrast, this article shows how a streamlined and thrifty CPU design, optimized for FPGAs, can achieve a cost-effective integrated computer system, even for low-volume products that can't justify an ASIC run."

XSOC/xr16 in XS40 photo


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Last updated: Mar 09 2001