A field-programmable object array (FPOA) is a class of

programmable logic device A programmable logic device (PLD) is an electronic component used to build reconfigurable digital circuits. Unlike digital logic constructed using discrete logic gates with fixed functions, a PLD has an undefined function at the time of manu ...

s designed to be modified or programmed after manufacturing. They are designed to bridge the gap between ASIC and FPGA. They contain a grid of programmable silicon objects. Arrix range of FPOA contained three types of silicon objects: arithmetic logic units (ALUs), register files (RFs) and multiply-and-accumulate units (MACs). Both the objects and interconnects are programmable.

Motivation and history

The device was intended to bridge the gap between

field-programmable gate arrays A field-programmable gate array (FPGA) is an integrated circuit designed to be configured by a customer or a designer after manufacturinghence the term '' field-programmable''. The FPGA configuration is generally specified using a hardware de ...

(FPGAs) and

application-specific integrated circuits An application-specific integrated circuit (ASIC ) is an integrated circuit (IC) chip customized for a particular use, rather than intended for general-purpose use, such as a chip designed to run in a digital voice recorder or a high-efficie ...

(ASICs). The design goal was to combine the programmability of FPGAs and the performance of ASICs. FPGAs, although programmable, lack performance; they may only be clocked to few hundreds of megahertz and most FPGAs operated below 100 MHz. FPGAs did not offer deterministic timing and the maximum operating frequency depends on the design. ASICs offered good performance, but they could not be modified and they were very costly. The FPOA had a programmable architecture, deterministic timing, and gigahertz performance. The FPOA was designed by Douglas Pihl who had this idea when working on a

DARPA The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Ad ...

funded project. He founded MathStar in 1997 to manufacture FPOAs and the idea was

patented A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...

in 2004. The first FPOA prototypes were made in 2005 and first batch of FPOA chips were fabricated in 2006.

Architecture

FPOAs have a core grid of silicon objects or core objects. These objects are connected through a synchronous interconnect. Each core object also has a supporting structures for clock synchronization, BIST and the like. The core is surrounded by peripheral circuitry that contains memory and I/O. An interface circuitry connects the objects to rest of FPOA. Exact number of each type of object and its arrangement are specific to a given family. There are two types of communication: nearest member and "party-line". Nearest member is used to connect a core to nearest core object and party line is used to connect remote objects. There are 8 nearest neighbor interconnects per object and offers transmission speed on one object hop per clock cycle. There are 10 party line interconnect per object that offers transmission speed of four object hops per clock cycle.

Applications

FPOAs may be used almost anywhere an FPGA is used, broadly in all hardware acceleration tasks including digital signal processing, medical imaging, computer vision, speech recognition, cryptography, bioinformatics, computer hardware emulation, and

aerospace Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astr ...

. Since FPOAs are built around fast and optimized silicon objects, they offer higher performance in flat field error correction, fast Fourier transform computation, medical imaging,

machine vision Machine vision (MV) is the technology and methods used to provide imaging-based automatic inspection and analysis for such applications as automatic inspection, process control, and robot guidance, usually in industry. Machine vision refers to ...

, image encoding and decoding, video encoding and decoding and artificial intelligence acceleration to name a few.

Development on FPOA

In FPOA we work at silicon object level a higher level than the gate level used in FPGA. This eases the learning curve and also speeds up development. Programming is done in System C. The Arrix family released in 2006 was supported by FPOA design software, which enabled designers to create, verify, program and debug their algorithms on the devices. Summit Design's Visual Elite tool was used for behavioural simulation. MathStar's COAST (COnnection and ASsignment Tool) offered a graphical environment for floor-planning and placement it compiled to an intermediate code that maps to hardware resources. The Object compiler generated the file to be loaded into the FPGA. In 2007 MathStar struck a partnership with mentor graphics and subsequent release use Visual Elite editor from Mentor Graphics for behavioural simulation and functional verification. FPOAs also offered IP core library IP partners included professionals in the video market as well as machine vision market.

Present status

MathStar the producer of FPOAs never posted a profit and the company decided to shut down production in May 2008. MathStar was merged into Sajan Inc. in 2010 and Sajan thus acquired MathStar's patent including that of FPOAs. In November 2011, Sajan sold several of MathStar's patent including some on FPOAs to OLK Grun GmbH.

References

{{DEFAULTSORT:Field-Programmable Object Array Gate arrays Integrated circuits