The Connex Project

The Connex Project started with the Connex Memory.

Connex Memory: is the hardware support for efficient string store, search, insert, read and delete.

The concept of Connex Memory (CM) is a sequel of the Lisp Machine project (see the story in [Stefan '02]). The concept is first presented in [Stefan '85/91], but unpublished until 1991 because "the cabinet 2" has forbidden the use of the sintagm "artificial intelligence".

The main feature of CM consists in searching strings in "constant" time ("constant" instead constant because of a very small weighted log which is inevitably there due to of physical reasons). For example, if the string "george" is to be searched in a very big string, then the following sequence of commands identifies all the occurences of "george" and accesses the first:

find g;
cfind e;
cfind o;
cfind r;
cfind g;
cfind e;

John Sununu, explaining to Bill Frezza the reasons to invest in Connex Technology, uttered the best explanation for this feature of the Connex Memory:
Using Connex Memory, George searches "the needle in a hay stack" using time proportional with the size of "the needle" rather than time proportional with the size of "the stack".

The main development stages of the concept of CM

1. The initial definition

CM is a sort of associative memory containing a string of variables whose value can be accessed to be read or modified using the following set of simple one cycle operations: For an extended description see [Stefan '98a].

2. Exotic applications

A lot of exotic applications were investigated prior to 2001: The main colaborators: Mihaela Malita and Robert Benea

3. From CM to Connex Engine

In 2001 spring semester, during a sabatical half-year, the concept of CM is applied to bio-informatics and expanded in a colaborative work with Dominique Thiebaut. CM becomes Connex Engine (CE) expanding the physical resources from one-word cell to many-word cells.

The application domain investigated with CE is bioinformatics (see [Stefan '01] and Dominique's research web page).

The main outcome of this stage is the patent application issued in August 2001.

4. The Connex Architecture

In 2001 Fall semester the concept of Connex Architecture (CA) was developed with Dan Tomescu. The CE becomes now a general purpose computational architecture.

The first application investigated by Dan Tomescu using CA: in memory data bases.
The second application investigated was a SoC for still camera. Basic algorithms on CA where developed in colaboration with Mihaela Malita and Dominique Thiebaut.

The prototype version of ConnexArrayTM - an array of 4096 processing elements - was designed and produced at TSMC. Main collaborators: Bogdan Mitu (testing), Victor Radu-Radulescu (physical design).

5. Connex Technology

Starting from 2003 inside Connex Technology, Inc. (co-founded with Paul Conley, John Sununu, Dominique Thiebaut, Dan Tomescu) CA is developed as Connex Technology optimizing CA for a specific application domain: image processing. The main colaborators in this stage are: Bogdan Mitu, Dan Tomescu.

The company has built a PCI board deploying 4 of its ConnexArrayTM test chips, each of which contains 4,096 PEs. The board was used by Government Agencies for string searches of very large databases, utilizing the Connex machine capability to search for a string in a time proportional to the length of the string, rather than the size of the database, as is the case with conventional search engines.

Connex Technology is implemented and patented as the core of CA1024 chip produced by Connex Technology, Inc. (see [Stefan '06] for architectural description and for the basic performances). The new features added in this stage are: The first public presentation of Connex Technology occurs in Microprocessor Report.

In 2007 company changed its name in BrightScale.


6. NeoConnex Approach




Gheorghe Stefan, Dominique Thiebaut: Memory Engine for the Inspection and Manipulation of Data (United States Patent 6,760,821, February 20, 2003; Filed: August 10, 2001)
Gheorghe Stefan, Dominique Thiebaut, Dan Tomescu: Associative memory device (United States Patent 7,069,386, June 27, 2006; Filed: May 10, 2004)
Dan Tomescu, Gheorghe Stefan: Data processing system having a Cartesian Controller (United States Patent 7,107,478, September 12, 2006; Filed: December 4, 2003)
Gheorghe Stefan, Dan Tomescu: Cellular Engine for a Data Processing System, (United States Patent 7,383,421, June 3, 2008 ; Filed: December 4, 2003)
Bogdan Mitu, Gheorghe Stefan, Dan Tomescu: Array of Boolean logic controlled processing elements with concurrent I/O processing and instruction sequencing, (United States Patent 7,451,293, November 11, 2008 ; Filed: Oct. 21, 2005,)
Gheorghe Stefan, Dan Tomescu: Cellular Engine for a Data Processing System, (United States Patent 7,908,461, March 15, 2011 ; Filed: December 19, 2007)
Bogdan Mitu, Lazar Bivolarski, Gheorghe Stefan: System and method for class-based execution of an instruction broadcasted to an array of processing elements (United States Patent 9,563,433, February 7, 2017 ; Filed: December 18, 2012)


[Stefan '85/91] Gh. Stefan, V. Bistriceanu, A. Paun, "Catre un mod natural de implementare a LISP-ului" (Toward a Natural Way to Implement LISP), in Sisteme cu inteligenta artificiala (Systems for Artificial Intelligence), Ed. Academiei Romane, Bucuresti, 1991 (paper at Al doilea simpozion national de inteligenta artificiala (The Second National Symposium on Artificial Intelligence), Sept. 1985). p. 218 - 224.
[Stefan '86] Gh. Stefan, "Memorie conexa" (The Connex Memory) in CNETAC 1986 Vol. 2, IPB, Bucuresti, 1986, p. 79 - 81.
[Stefan '91] Gh. Stefan, F. Draghici, "Memory Management Unit - a New Principle for LRU Implementation" in Proceedings of 6th Mediterranean Electrotechnical Conference, Ljubljana, Yugoslavia, May 1991. p. 989 - 992.
[Stefan '91a] Gh. Stefan, F. Draghici, "Memory Management Unit with a Performant LRU Circuit" in Buletinul IPB, Tom LIII, Nr. 1-2, 1991. p. 89 -96.
[Stefan '95] Gh. Stefan, Mihaela Malita, "The Eco-Chip: A Physical Support for Artificial Life Systems", in Artificial Life. Grammatical Models, ed. by Gh. Paun, Black Sea University Press, Bucharest, 1995. p. 260 - 275.
[Hascsi '95a] Z. Hascsi, Gh. Stefan, "The Connex Content Addressable Memory (C2AM)" in Proceedings ot the Twenty-first European Solid-State Circuits Conference, Lille - France, 19 - 21 Sept. 1995, p.422-425.
[Stefan '96] Gh. Stefan, Mihaela Malita, "Chaitin's Toylisp on a Connex Memory Machine", in Journal of Universal Computer Science, Vol. 2, No. 5, May 28, 1996, p.410 - 426. (Special Issue: C. Calude (ed.): The Finite the Unbounded and the Infinite, Proceedings of the Summer School "Chaitin,s Complexity and Applications", 27 June - 6 July, 1995.)
[Hascsi '96a] Z. Hascsi, B. Mitu, M. Petre, G. Stefan, "High-Level Synthesis of an Enchanced Connex memory", in Proceedings of the International Semiconductor Conference, Sinaia, October 1996, p. 163-166.
[Stefan '97] Gh. Stefan, Mihaela Malita, "DNA Computing with the Connex Memory", in RECOMB 97 First International Conference on Computational Molecular Biology, January 20 - 23, Santa Fe, New Mexico, 1997. p. 97-98.
[Stefan '97a] Gh. Stefan, Mihaela Malita, "The Splicing Mechanism and the Connex Memory", Proceedings of the 1997 IEEE International Conference on Evolutionary Computation, Indianapolis, April 13 -16, 1997. p. 225-229.
[Stefan '98] Gh. Stefan, Robert Benea, "Connex Memories & Rewriting Systems", in MELECON '98 9th Mediterranean Electrotechnical Conference, May 18-20, 1998, Tel-Aviv, Israel. p 1299-1303.
[Stefan '98a] Gh. Stefan, "The Connex Memory: A Physical Support for Tree / List Processing", in The Roumanian Journal of Information Science and Technology, Vol.1, Number 1, 1998, p. 85 - 104.
[Stefan '98b] Gh. Stefan, "Silicon or Molecules? What's the Best for Splicing", in Gh.Paun (ed.) Computing with Bio-Molecules. Theory and Experiments, in Springer, 1998. p. 158-181
[Stefan '01] Gh. Stefan, Dominique Thiebaut, "Hardware-Assisted String-Matching Algorithms", in WABI 2001, 1st Workshop on Algorithms in BioInformatics, BRICS, University of Aarhaus, Danemark, August 28-31, 2001.
[Stefan '02] G. Stefan: "Masina DIALISP - o realizare cu efecte intarziate", in Computers and Computer Networks in Romania 1953-1985, Romanian Academy, 11/22/2001.
[Stefan '06a] G. Stefan: "The CA1024: A Massively Parallel Processor for Cost-Effective HDTV", in SPRING PROCESSOR FORUM: Power-Efficient Design, May 15-17, 2006, Doubletree Hotel, San Jose, CA.
[Stefan '06b] G. Stefan: "The CA1024: A Massively Parallel Processor for Cost-Effective HDTV", in SPRING PROCESSOR FORUM: Power-Efficient Design, June 8-9, 2006, Tokyo
[Malita '06] Mihaela Malita, Gheorghe Stefan, Marius Stoian: "Complex vs. Intensive in Parallel Computation", in International Multi-Conference on Computing in the Global Information Technology - Challenges for the Next Generation of IT&C - ICCGI 2006 Bucharest, Romania, August 1-3, 2006.
[Thiebaut '06] Dominique Thiebaut, Gheorghe Stefan, Mihaela Malita: "DNA search and the Connex technology" in International Multi-Conference on Computing in the Global Information Technology - Challenges for the Next Generation of IT&C - ICCGI 2006 Bucharest, Romania, August 1-3, 2006.
[Stefan '06c] Gheorghe Stefan, Anand Sheel, Bogdan Mitu, Tom Thomson, Dan Tomescu: "The CA1024: A Fully Programable System-On-Chip for Cost-Effective HDTV Media Processing", in Hot Chips: A Symposium on High Performance Chips, Memorial Auditorium, Stanford University, August 20 to 22, 2006.
[Stefan '06d] Gheorghe Stefan: "The CA1024: SoC with Integral Parallel Architecture for HDTV Processing", invited paper at 4th International System-on-Chip (SoC) Conference & Exhibit, Radisson Hotel Newport Beach, CA, November 1 & 2, 2006.
[Malita '07] Mihaela Malita, Gheorghe Stefan, Dominique Thiebaut: "Not Multi-, but Many-Core: Designing Integral Parallel Architectures for Embedded Computation" in ACM SIGARCH Computer Architecture News, Volume 35 , Issue 5, Dec. 2007, Special issue: ALPS '07 - Advanced low power systems; communication at International Workshop on Advanced Low Power Systems held in conjunction with 21st International Conference on Supercomputing June 17, 2007 Seattle, WA, USA.
[Malita '08] Mihaela Malita, Gheorghe Stefan: "On the Many-Processor Paradigm", in: H. R. Arabina (Ed.): Proceedings of the 2008 World Congress in Computer Science, Computer Engineering and Applied Computing, vol. PDPTA'08 (The 2008 International Conference on Parallel and Distributed Processing Techniques and Applications), 2008.
[Stefan '09] Gheorghe Stefan: "One-Chip TeraArchitecture", in Proceedings of the 8th Applications and Principles of Information Science Conference, Okinawa, Japan on 11-12 January 2009.
[Mitu '09] Bogdan Mitu, Gheorghe M. Stefan: Stereo Vision for Automotive Industry on Connex Architecture, DCAE-ETTI Research report, 2009.
[Stefan '10] Gheorghe Stefan: "Integral Parallel Architecture in System-on-Chip Designs", in The 6th International Workshop on Unique Chips and Systems, Atlanta, GA, USA, December 4, 2010, pag. 23-26.
[Lorentz '10] I. Lorentz, M. Malita, R. Andonie: "Fitting FFT onto an Energy Efficient Massively Parallel Architecture", in The Second International Forum on Next Generation Multicore/ Manycore Technologies, June, 2010.
[Lorentz '11] Istvan Lorentz, Mihaela Malita, Razvan Andonie: "Evolutionary Computation on the Connex Architecture", in The 22nd Midwest Artificial Intelligence and Cognitive Science Conference, Cincinnati, Ohio, 2011.
[Malita '11] Mihaela Malita, Gheorghe M. Stefan: "Parallel RISC Architecture. A Functional Approach Based on Backus's FP language", in The 2011 International Conference on Parallel and Distributed Processing Techniques and Applications, Las Vegas, 2011.
[Malita '12] Mihaela Malita, Gheorghe M. Stefan: "Architectural Principles for One-Chip Parallel Computer", in Recent Advances in Information Science. Proceedings of the 3rd European Conference of Computer Science, Paris, France, December 2-4, 2012, pp 143-148.
[Malita '15] Mihaela Malita, Gheorghe M. Stefan: "From Kleene's Model to the Parallel Abstract Machine" (unpublished)