On designing ULM-based FPGA logic modules

Shashidhar Thakur, D. F. Wong

Research output: Contribution to conferencePaperpeer-review


In this paper, we give a method to design FPGA logic modules, based on an extension of classical work on designing Universal Logic Modules (ULM). Specifically, we give a technique to design a class of logic modules that specialize to a large number of functions under complementations and permutations of inputs, bridging of inputs and assignment of 0/1 to inputs. Thus, a lot of functions can be implemented using a single logic module. The significance of our work lies in our ability to generate a large set of such logic modules. A choice can be made from this set based on design criteria. We demonstrate the technique by generating a set of 471 8-input functions that have a much higher coverage than the 8-input cells employed by Actel's FP-Gas. Our functions can specialize to up to 23 times the number of functions that Actel functions can. We also show that by carefully optimizing these functions one can obtain multilevel implementations of them that have delays within 10% of the delays of Actel modules. We demonstrate the effectiveness of these modules in mapping benchmark circuits. We observed a 16% reduction in area and a 21% reduction in delay using our logic modules instead of Actel's on these circuits.

Original languageEnglish (US)
Number of pages7
StatePublished - 1995
Externally publishedYes
EventProceedings of the 1995 ACM 3rd International Symposium on Field-Programmable Gate Arrays - Monterey, CA, USA
Duration: Feb 12 1995Feb 14 1995


OtherProceedings of the 1995 ACM 3rd International Symposium on Field-Programmable Gate Arrays
CityMonterey, CA, USA

ASJC Scopus subject areas

  • General Computer Science


Dive into the research topics of 'On designing ULM-based FPGA logic modules'. Together they form a unique fingerprint.

Cite this