混合基可重构FFT处理器的设计与实现

本文提出了一种新型混合基可重构FFT处理器,由支持基-2/3FFT的新型可重构蝶形单元和多路并行无冲突的存储器组成,实现了FFT过程中多路数据并行性和操作的连续性.本设计在TSMC28nm工艺下的最高频率为1.06GHz,同时在Xilinx的XC7V2000T FPGA芯片上搭建了混合基FFT处理器硬件测试系统.对混合基FFT处理器的FPGA硬件测试结果表明,本设计支持基-2、基-3和基-2/3混合模式FFT变换,且执行速度达到给定蝶乘器数量下的理论周期值,对单精度浮点数,混合基FFT处理器可提供10-5的结果精度.     

一种新型高速低成本可重构FFT处理器结构

文中提出了一种基于FPGA的高速可重构FFT处理器结构.该结构采用精简控制算法[1]可针对从32点到1024点等不同点数数字信号进行FFT处理,并且在Xilinx公司Virtex2p系列FPGA上进行了综合及后仿真.结果表明该可重构结构相比Xilinx IP core而言资源占用减少16%~21%(slice),最高时钟频率提高了10%~30%,输入输出延时减少了56~116个时钟周期,运算效率明显提高,而功耗相当.可适用于低成本高速数字信号处理系统.     

空间太阳望远镜星载数据处理系统中的 动态可重构协处理器研究

本文提出了一种为空间太阳望远镜星载数据处理系统而设计的动态可重构协处理器方案,该方案利用4bits粒度可重构阵列将传统的基于指令流的运算方式变为基于数据流与配置流的运算方式,并通过指令流水实现了动态可重构单元与主处理器的协同工作.文章最后还给出了该方案在Xilinx XC2V3000上的实现及该实现用于乘法和1024点复数快速傅立叶变换时的性能.     

应用于视频处理的可重构流处理器的设计与实现

设计了一款新的应用于多媒体处理领域的可重构多媒体流处理器.该可重构多媒体流处理器采用并行处理机制,在经过算法映射后,可以充分利用多媒体算法的高并行度,同时实时处理不同的多媒体算法.该架构在Xilinx的Virtex4芯片上通过验证,并与ARM9处理器共同构成嵌入式多媒体处理平台,验证处理H.264和AVS的解码过程.     

高速基2 FFT处理器的结构设计与FPGA实现

本文研究了采用AISC来实现高速实时基2 FFT处理器的设计方案.在实现中采用了单基2定点内核,设计了防溢出控制结构,在不增加系统延时的基础上,提高了运算精度.设计了对称乒乓RAM结构,在保证蝶形运算核的占用率的条件下,提高了该FFT处理器的连续运算能力.将RAM集成在FFT处理器内部,提高了使用的灵活性.本文所设计的FFT具有可配置特性,可根据需要计算2的幂次方的FFT.256点的FFT运算只需1072个时钟周期,在VertexII-xc2v1000上综合实现,频率可达112.007MHz,完成整个256点的FFT运算仅需9.57μs.     

基于FPGA的动态可重构系统实现

介绍了Xilinx公司VirtexTMFPGA芯片的配置原理,采用模块化设计实现FPGA的动态部分重构,并设计出CPU加CPLD配置FPGA的硬件方案来实现可重构系统.FPGA采用Select MAP配置方式,实现配置逻辑的快速重构和动态部分重构.同时给出了可重构系统配置的软件流程,并计算出相应的重构时间.     

浮点FFT的VHDL实现

随着集成电路技术的发展,电子设计自动化逐渐成为重要的设计手段,已经广泛应用于数字电路和数字信号处理系统等许多领域.文中介绍了基于VHDL语言设计的浮点FFT,本设计采用基2算法,单精度32位二进制的浮点形式,主控制器采用状态机建模.整个设计利用Xilinx公司提供的先进的ISE 5.3系列软件,采用了先进的结构化设计思想.总设计通过了Modelsim仿真与验证,二十多个模块的代码覆盖率达到100%.实践结果表明,应用VHDL实现的FFT处理器可快速完成浮点数据快速傅式变换,代码覆盖率也表明系统的测试工作比较完备.该系统可扩展到16点,32点的浮点FFT运算.     

基于模块局部可重构FIR滤波器设计

介绍了一种使用动态局部重构技术设计可重构FIR数字滤波器的方法,是一种注重面积效率高、灵活性强,允许动态插入或删除局部模块的方法,并在Xilinx Virtex-4 FPGA上实现.这种设计方法比传统的FIR滤波器的设计方法具有占用资源更少、重构时间更短、高速灵活性等优点.     

基于System Generator的动态局部可重构设计方法

在动态局部可重构设计过程中,系统级设计到现场可编程门阵列（FPGA）硬件实现,还需要大量的寄存器传输级（RTL）硬件语言编写,导致设计效率下降的问题。针对该问题,以Xilinx公司最新提出的动态局部重构设计流程———早期获取部分可重构（EAPR）为基础,利用System Generator软件,提出一种动态局部重构的设...     

FPGA动态局部可重构中基于TBUF总线宏设计

FPGA动态局部可重构技术通常将系统划分为固定模块和可重构模块,可重构模块与其他模块之间的通信都是通过使用特殊的总线宏实现的.总线宏的正确设计是实现FPGA动态局部可重构技术的关键.在研究了FPGA动态局部可重构技术中基于三态缓冲器(Tri-state Buffer,TBUF)总线宏结构的基础上,采用Xilinx ISE FPGA Editor可视化的方法实现总线宏的设计,并借助可重构硬件平台--XCV800验证板,通过设计动态可重构实验,论证总线宏设计的正确性.     

Dynamic Partial Reconfigurable FFT for OFDM Based Communication Systems

This paper presents a novel scalable and runtime dynamically reconfigurable FFT architecture for different wireless standards. With only 8 butterfly units, a reconfigurable FFT architecture for three different FFT points is realized using mixed radix-2²/2³/2⁴ FFT algorithm in a modified Single-path Delay Feedback (SDF) pipelined architecture. Via a proper data flow reconfiguration it can support 64, 128 and 256. It can even be extended up to 8192-point transforms and uses only 13 butterfly units to realize 8192 points. This paper describes the implementation method of 256 and 128 point FFT, which is reconfigured partially from 64 point FFT. The whole system is implemented on a Xilinx XC2VP30 FPGA device. The implementation design addresses area efficiency and flexibility allowing the insertion of the partial modules dynamically to realize various FFT sizes. To verify the efficacy of this dynamic partial reconfigurable FFT design method, a conventional multiplexer based reconfigurable architecture was designed and tested on the same platform. Tested FPGA results for the Dynamic Partial Reconfigurable (DPR) method show the configuration time improvement and good area efficiency as compared to the reconfigurable architecture using conventional multiplexer techniques.     

Parallel Memory Accessing for FFT Architectures

The current paper introduces an efficient technique for parallel data addressing in FFT architectures performing in-place computations. The novel addressing organization provides parallel load and store of the data involved in radix-r butterfly computations and leads to an efficient architecture when r is a power of 2. The addressing scheme is based on a permutation of the FFT data, which leads to the improvement of the address generating circuit and the butterfly processor control. Moreover, the proposed technique is suitable for mixed radix applications, especially for radixes that are powers of 2 and straightforward continuous flow implementation. The paper presents the technique and the resulting FFT architecture and shows the advantages of the architecture compared to hitherto published results. The implementations on a Xilinx FPGA Virtex-7 VC707 of the in-place radix-8 FFT architectures with input sizes 64 and 512 complex points validate the results.     

一种可重构阵列结构及其任务调度算法

提出了一种可以利用计算时间覆盖配置时间和数据传输时间的可重构阵列结构,并且针对该可重构阵列结构提出了一种表调度算法进行任务调度.在SOCDesigner平台上进行了软硬件协同仿真,对于IDCT,FFT,4×4矩阵乘法新可重构阵列相比原来的可重构阵列有平均约10%的速度提升.     

基于FPGA的可配置 FFT IP核实现研究

针对FFT算法基于FPGA实现可配置的IP核。采用基于流水线结构和快速并行算法实现了蝶形运算和4 k点FFT的输入点数、数据位宽、分解基自由配置。使用Verilog 语言编写,利用ModelSim仿真,由ISE综合并下载,在Xilinx公司的Virtex-5 xc5vfx70t器件上以200 MHz 的时钟实现验证,运算结果与其他设计的运算效率对比有一定优势     

SFF—The Single-Stream FPGA-Optimized Feedforward FFT Hardware Architecture

In this paper, a fast Fourier transform (FFT) hardware architecture optimized for field-programmable gate-arrays (FPGAs) is proposed. We refer to this as the single-stream FPGA-optimized feedforward (SFF) architecture. By using a stage that trades adders for shift registers as compared with the single-path delay feedback (SDF) architecture the efficient implementation of short shift registers in Xilinx FPGAs can be exploited. Moreover, this stage can be combined with ordinary or optimized SDF stages such that adders are only traded for shift registers when beneficial. The resulting structures are well-suited for FPGA implementation, especially when efficient implementation of short shift registers is available. This holds for at least contemporary Xilinx FPGAs. The results show that the proposed architectures improve on the current state of the art.     

高效可配置浮点FFT处理器设计

为了克服高精度浮点FFT处理器具有较大资源开销的设计瓶颈,采用基于单口存储器的FIFO构建共享蝶形结构的R2/22SDF流水可配置结构.采用适合浮点设计的基2/22算法实现流水结构,不仅有利于可配置电路的实现,还能够有效减少复数乘法次数,提高复数乘法器的计算效率.采用双倍数据位宽的单口存储器实现FIFO存储器,有效避免了双口存储器面积和功耗较大的问题.改进的蝶形共享结构实现两级蝶形的合并,解决了单路径延迟反馈流水线结构蝶形单元利用率低的问题.与传统流水线结构FFT处理器设计相比,有效降低了浮点设计中的资源开销,提高了计算单元的利用效率.     

Application of Reconfigurable Computing to a High Performance Front-End Radar Signal Processor

Many radar sensor systems demand high performance front-end signal processing. The high processing throughput is driven by the fast analog-to-digital conversion sampling rate, the large number of sensor channels, and stringent requirements on the filter design leading to a large number of filter taps. The computational demands range from tens to hundreds of billion operations per second (GOPS). Fortunately, this processing is very regular, highly parallel, and well suited to VLSI hardware. We recently fielded a system consisting of 100 GOPS designed using custom VLSI chips. The system can adapt to different filter coefficients as a function of changes in the transmitted radar pulse. Although the computation is performed on custom VLSI chips, there are important reasons to attempt to solve this problem using adaptive computing devices. As feature size shrinks and field programmable gate arrays become more capable, the same filtering operation will be feasible using reconfigurable electronics. In this paper we describe the hardware architecture of this high performance radar signal processor, technology trends in reconfigurable computing, and present an alternate implementation using emerging reconfigurable technologies. We investigate the suitability of a Xilinx Virtex chip (XCV1000) to this application. Results of simulating and implementing the application on the Xilinx chip is also discussed.     

System-level power-performance tradeoffs for reconfigurable computing

In this paper, we propose a configuration-aware data-partitioning approach for reconfigurable computing. We show how the reconfiguration overhead impacts the data-partitioning process. Moreover, we explore the system-level power-performance tradeoffs available when implementing streaming embedded applications on fine-grained reconfigurable architectures. For a certain group of streaming applications, we show that an efficient hardware/software partitioning algorithm is required when targeting low power. However, if the application objective is performance, then we propose the use of dynamically reconfigurable architectures. We propose a design methodology that adapts the architecture and algorithms to the application requirements. The methodology has been proven to work on a real research platform based on Xilinx devices. Finally, we have applied our methodology and algorithms to the case study of image sharpening, which is required nowadays in digital cameras and mobile phones.     

Design and Implementation of 256‐Point Radix‐4 100 Gbit/s FFT Algorithm into FPGA for High‐Speed Applications

The third‐party FFT IP cores available in today's markets do not provide the desired speed demands for optical communication. This study deals with the design and implementation of a 256‐point Radix‐4 100 Gbit/s FFT, where computational steps are reconsidered and optimized for high‐speed applications, such as radar and fiber optics. Alternative methods for FFT implementation are investigated and Radix‐4 is decided to be the optimal solution for our fully parallel FPGA application. The algorithms that we will implement during the development phase are to be tested on a Xilinx Virtex‐6 FPGA platform. The proposed FFT core has a fully parallel architecture with a latency of nine clocks, and the target clock rate is 312.5 MHz.