一种基于HXDSP的移位器查找表技术

高性能信号处理应用的快速发展，对相应处理器的运算速度及吞吐效率提出了巨大挑战。移位器是数字信号处理器（DSP）上的重要部件，通过为移位器设计额外专用随机存取存储器（RAM）和查找表（LUT），并对其指令集及架构进行优化调整，从而达到提高处理器使用效率和传输速率的目的。此外，基于移位器与相应查找表指令，可在数据暂存的同时进行移位、提取、算术与逻辑运算处理，将部分数据运算的过程直接合并在对移位器RAM的数据存读取过程中，显著地提高了运算部件的使用效率。结果表明:基于移位器查找表的暂存技术可以达到与传输总线接近的吞吐率，对信号处理算法快速傅里叶变换（FFT）可以达到加速比约为1.15~1.20的性能提升效果。 

A shifter look-up table technique based on HXDSP

With the development of digital signal processing technology, the application of high-performance signal processing has attracted more and more attention, which also poses great challenges to the computing speed and throughput efficiency of the corresponding processors. The shifter unit is an important component on the digital signal processor (DSP). By designing additional dedicated random access memory (RAM) and look-up table (LUT) for the shifter unit, this paper optimizes and adjusts its instruction set and architecture, so as to improve the use efficiency and transmission rate of the processor. In addition, based on the shifter and the corresponding look-up table instruction, it can carry out shift, extraction, arithmetic and logical operation processing at the same time of data temporary storage. And the process of the partial data operation is directly merged into the data read/write process of the shifter RAM, which greatly improves the efficiency of arithmetic unit. Experiments show that the temporary storage technology based on the shifter look-up table can achieve the throughput rate close to the transmission bus, and the signal processing algorithm fast Fourier transformation (FFT) can achieve the performance improvement of the acceleration ratio of 1.15 to 1.20.