An Efficient Conflict-free Memory-addressing Unit for SIMD VLIW DSP

摘要

With the rapid expansion in multi-media and signal processing applications, DSP processors with high-performance execution and low-power consumption evoke to be the trend. As these applications are often characterised by a huge number of data accesses, the computation efficiency often be heavily decreased by bank conflicts on a ccount of non-aligned and irregular data accesses. This paper presents an efficient memory accessing unit called Mod-N Address for the DSP processor. The unit is designed for solving bank conflicts when data accessing is irregular or not aligned. The proposed architecture implements the conflict-free access by generating addresses through modulus operation and accessing along the diagonal. The structure adjusts the sequence of data when accessing and requires quite little changes to the instruction set. The unit had been implemented on our platform BWDSP104x, and the experimental results had shown that proposed unit achieves an 45% accelerate rate for FFT algorithm compared with the previous scheme. According to the comparison with the conventional methods, experimental evaluations also show that mod-N address can outperform by an average of 7.9% to 60% in performance.