The evolution of DSP processors

The number and variety of products that include some form of digital signal processing (DSP) has grown dramatically. DSP has become a key component in many consumer, communications, medical, and industrial products, which use a variety of hardware approaches to implement DSP, ranging from the use of off-the-shelf microprocessors to field-programmable gate arrays (FPGAs) to custom integrated circuits (ICs). Programmable “DSP processors”, a class of microprocessors optimized for DSP, are a popular solution for several reasons: they can potentially be reprogrammed in the field, allowing product upgrades or fixes. They are often more cost-effective (and less risky) than custom hardware, particularly for low-volume applications, where the development cost of custom ICs may be prohibitive. In comparison to other types of microprocessors, DSP processors often have an advantage in terms of speed, cost, and energy efficiency. In this article, we trace the evolution of DSP processors from early architectures to current state-of-the-art devices. We highlight some of the key differences among architectures and compare their strengths and weaknesses. Finally, we discuss the growing class of general-purpose processors that have been enhanced to address the needs of DSP applications