Abstract: A communications reduced instruction processor forming a simple programmable digital signal processing architecture (10) for processing analog waveforms. The architecture (10) includes a main DSP core that includes a tightly coupled CORDIC co-processing element (26). The CORDIC co-processing element (26) performs trigonometric operations for converting polar coordinates to rectangular coordinates and rectangular coordinates to polar coordinates. These trigonometric functions include an angle accumulate operation for calculating the magnitude and angle of a vector given in X-Y cartesian coordinates, and a vector rotate operation for calculating a sine and a cosine of a given phase angle.

Abstract: A waveform characterizer apparatus is disclosed for extracting cepstrum pitch and spectral properties of a waveform signal such as the baseband audio output of a receiver. The apparatus employs Fourier processing, cepstral processing, magnitude detection, logarithms processing, frequency selective filtering and time/frequency windowing to extract cepstrum pitch and spectral rolloff characteristics which can then be used to determine the signal type. One application of the invention is in a digital voice/squelch apparatus.