DSPs (Digital Signal Processors) are processors specifically designed for digital signal processing. The diversity of applications has enabled these devices to evolve considerably since they first appeared in the 1980s. The best-known example is the TMS32010 fixed-point DSP from Texas Instruments, the world market leader in this type of technology. In fact, there are two main families of this type of processor: fixed-point DSPs using integer arithmetic, and floating-point DSPs operating in floating-point arithmetic. The latter are the fastest and most accurate, but also the most expensive. In this book, we present the general characteristics found in most DSPs, the so-called 'conventional' architecture found in first-generation DSPs and in the vast majority of today's processors, the general history tracing the evolution of these different architectures up to the most recent, the place occupied by DSPs relative to other computing structures and, finally, the DSP software development tool.