A high-performance embedded DSP core with novel SIMD features

A low-power, high-performance, compiler-friendly DSP core has been under development in the IBM Communications Research & Development Center, as part of its elite DSP project. This DSP incorporates instruction-level parallelism through the packing of multiple instructions in 64-bit long-instruction words, while data-level parallelism is realized through the use of SIMD techniques, such that SIMD operations can be applied to both dynamically composed vectors and packed vectors. Dynamic composition of vectors is made possible through the use of a vector pointer mechanism, which permits the addressing in a very flexible way of groups of four 16-bit elements in a large, multiport, scalar register file. This paper provides an overview of the architecture of this DSP core, with a focus on its SIMD features. We describe these features in some detail and discuss how they are used, with a block FIR filter and a radix-4 FFT taken as examples.