滑动窗口应用循环展开及其数据通路生成

滑动窗口广泛应用于图像处理、模式识别和数字信号处理中,它具有数据量大、计算密集等特点.可重构硬件为滑动窗口应用提供了一个灵活高效的实现平台.文中基于一种存储、数据调度模型及其相应的数据通路生成技术,研究循环展开对滑动窗口应用的面积、时钟频率和吞吐率的影响.实验结果表明内层循环展开相对于外层循环展开将带来更大的控制复杂度,增加了对芯片面积的需求,然而外层循环展开需要更多的存储资源保存重用数据;当片内存储模块个数增加到一定规模时,时钟频率将随着循环展开不断降低;不同维度的应用,吞吐率随循环展开提升程度不同.

Loop Unrolling and Data-Path Generation of Sliding-Window Operation

Window operations which are computationally intensive and data intensive are frequently used in image compression,pattern recognition and digital signal processing.Reconfigurable hardware boards provide a convenient and flexible solution to speed up these algorithms.Based on a memory and data schedule method as well as the method of data-path generation,this paper studies the effect of loop unrolling on the area,clock speed and throughput for sliding window operations.The results indicate that due to the unique design of the compilation framework,inner loop unrolling makes the controllers become more complicated than outer loop unrolling and increase more requirements of areas at the same time.However,outer loop unrolling demands more memory elements to keep the reused data.The clock speed begins to decrease when the number of RAM modules extends to a certain size,and the throughput increase in different degrees for different operations.