Overview
Field-programmable gate array (FPGA) technology continues to gain momentum, and the worldwide FPGA market is expected to grow from $1.9 billion in 2005 to $2.75 billion by 20101. Since its invention by Xilinx in 1984, FPGAs have gone from being simple glue logic chips to actually replacing custom application-specific integrated circuits (ASICs) and processors for signal processing and control applications. Why has this technology been so successful? This article provides an introduction to FPGAs and highlights some of the benefits that make FPGAs unique.
What is an FPGA?
At the highest level, FPGAs are reprogrammable silicon chips. Using prebuilt logic blocks and programmable routing resources, you can configure these chips to implement custom hardware functionality without ever having to pick up a breadboard or soldering iron. You develop digital computing tasks in software and compile them down to a configuration file or bitstream that contains information on how the components should be wired together. In addition, FPGAs are completely reconfigurable and instantly take on a brand new “personality” when you recompile a different configuration of circuitry. In the past, FPGA technology was only available to engineers with a deep understanding of digital hardware design. The rise of high-level design tools, however, is changing the rules of FPGA programming, with new technologies that convert graphical block diagrams or even C code into digital hardware circuitry.
FPGA chip adoption across all industries is driven by the fact that FPGAs combine the best parts of ASICs and processor-based systems. FPGAs provide hardware-timed speed and reliability, but they do not require high volumes to justify the large upfront expense of custom ASIC design. Reprogrammable silicon also has the same flexibility of software running on a processor-based system, but it is not limited by the number of processing cores available. Unlike processors, FPGAs are truly parallel in nature so different processing operations do not have to compete for the same resources. Each independent processing task is assigned to a dedicated section of the chip, and can function autonomously without any influence from other logic blocks. As a result, the performance of one part of the application is not affected when additional processing is added.
Top Five Benefits of FPGA Technology
【概述】
場域可程式化閘陣列 (FPGA) 技術(shù)正持續(xù)發(fā)展，而全世界 FPGA 市場的產(chǎn)值，則預(yù)估可從 2005 年的 19 億美金提升到 2010 年的 27 億 5 千萬美金。FPGA 是在 1984 年由 Xilinx 公司所發(fā)明，從簡單的膠合邏輯 (Glue logic) 晶片，演變?yōu)榭扇〈椭频奶囟☉?yīng)用積體電路 (ASIC) 與處理器，適用于訊號處理與控制應(yīng)用。為何 FPGA 技術(shù)如此成功？此篇文章將介紹 FPGA，并說明數(shù)項(xiàng)讓 FPGA 如此獨(dú)特的優(yōu)點(diǎn)。
何謂 FPGA？
最籠統(tǒng)來說，F(xiàn)PGAs 即為可再程式化的晶片。透過預(yù)先建立的邏輯區(qū)塊與可程式化路由資源，不需更改面包板或焊錫部分，即可設(shè)定這些晶片以建置客制硬體功能。使用者可于軟體中開發(fā)數(shù)位運(yùn)算系統(tǒng) (Computing task) 并將之編譯為組態(tài)檔案或位元流 (Bitstream)，可包含元件接線的相關(guān)資訊。此外，F(xiàn)PGA 完全為可重設(shè)性質(zhì)，當(dāng)使用者重新編譯不同的電路設(shè)定時，可立刻擁有不同的特性。在過去，工程師必須深入了解數(shù)位硬體設(shè)計(jì)，才能夠使用 FPGA 技術(shù)。然而，高階設(shè)計(jì)工具的新技術(shù)可針對圖形化程式區(qū)或 C 程式碼，轉(zhuǎn)換為數(shù)位硬體電路，即變更了 FPGA 程式設(shè)計(jì)的規(guī)則。
FPGA 整合了 ASIC 與處理器架構(gòu)系統(tǒng)的最佳部分，使 FPGA 晶片可應(yīng)用于所有產(chǎn)業(yè)。FPGA 具有硬體時脈的速度與可靠性，且其僅需少量即可進(jìn)行作業(yè)；可降低客制化 ASIC 設(shè)計(jì)的費(fèi)用?？芍匦鲁淌皆O(shè)計(jì)的晶片，具有與軟體相同的彈性，卻不受限于處理核心的數(shù)量。與處理器不同的是，F(xiàn)PGA 為實(shí)際的平行架構(gòu)，因此不同的處理作業(yè)并不需要占用相同資源。每個獨(dú)立的處理作業(yè)均將指派至專屬的晶片區(qū)塊，不需影響其他邏輯區(qū)塊即可自動產(chǎn)生功能。因此，當(dāng)新增其他處理作業(yè)時，應(yīng)用某部分的效能亦不會受到影響。
FPGA 技術(shù)的 5 大優(yōu)點(diǎn) ：
效能– 透過硬體的平行機(jī)制，F(xiàn)PGA 可突破依序執(zhí)行 (Sequential execution) 的固定運(yùn)算，并于每時脈循環(huán)完成更多作業(yè)，以超越數(shù)位訊號處理器 (DSP) 的計(jì)算功能。BDTI 為著名的分析公司，并于某些應(yīng)用中使用 DSP 解決方案，以計(jì)算 FPGA 的處理效能2。于硬體層級控制 I/O 可縮短回應(yīng)時間并特定化某些功能，以更符合應(yīng)用需求。