快速DCT修剪在DSP上的内存访问优化方法  

Memory Access Optimization Method for the Implementation of Fast DCT Pruning on DSP

作　　者：刘项洋[1] 许勇[1] 

机构地区：[1]安徽师范大学数学计算机科学学院,安徽芜湖241000

出　　处：《电子学报》2016年第1期227-232,共6页Acta Electronica Sinica

摘　　要：在本论文中,我们提出一个新的内存访问优化方法以减少由权重因子(在DCT的快速修剪计算图中的余弦系数)和输入点而产生的内存访问量,实现在DSP上的快速DCT修剪.该方法通过两个步骤来减少内存访问量:1.减少权重因子的个数;2.将快速DCT修剪的计算流程图中两个阶段中的蝴蝶运算单元合并到一个阶段中,从而形成一个高效的蝴蝶运算单元.我们在TI TMSC320C64x DSP上应用该方法来实现修剪FCT.实验结果表明,与传统的实现方法相比,修剪FCT方法在DSP上可以平均减少40%的内存访问量,平均减少48.6%的时钟周期和平均节约32.6%的由存储加权因子导致的内存访问.In this paper,we propose a memory access optimization method to minimize the memory accesses due to weighting factors（ cosine coefficients in the computation diagram of fast DCT pruning） and input points for implementing fast DCT pruning on DSP. The proposed method reduces the number of memory accesses in two steps： 1. Reduce the number of weighting factors; 2. Combine butterflies at two stages in fast DCT pruning diagram to form an efficient butterfly structure in one stage and calculate them. The proposed method is applied to implement Pruning FCT on TI TMSC320C64 x DSP. Experimental results showthat the proposed method can achieve an average of 40% memory access reduction,48. 6% clock cycle reduction and 32. 6% of memory space saving for weighting factors to compute Pruning FCT on DSP comparing with the conventional implementation.

关 键 词：数字信号处理器(DSP) 离散余弦变换(DCT) 内存访问 

分 类 号：TN911.23[电子电信—通信与信息系统]