General-purpose microprocessor performance for DSP applications

Digital signal processors (DSPs) have been used to realize real-time signal processing systems using hardware architectures and software instruction sets that are optimized for such applications. However, general-purpose microprocessors have risen in capability to the point that they can serve as alternative platforms for digital signal processing applications, particularly for audio-rate systems. This paper compares the capabilities of two general-purpose microprocessors-the Apple/IBM/Motorola PowerPC 604 and Intel Pentium PB-with the popular Texas Instruments´ TMS320C40 DSP on a suite of three common signal processing subsystems: (i) a finite-impulse-response (FIR) filter, (ii) the least-mean-square (LMS) adaptive filter, and (iii) the fast Fourier transform (FFT). Careful attention is paid to the architectures of the processors to obtain the most computationally-efficient realizations. The results indicate that general-purpose microprocessors are viable computational engines for audio-rate processing.