Abstract: A programmable finite impulse response processor, by which a convolution calculation between input data and filter coefficients is performed based on Booth algorithm. The processor include a pre-processing unit, data latches, a configurable connection unit, Booth decoders, coefficient registers, a path control unit, and a post-processing unit. The pre-processing unit is used to partition the input data into a pipeline sequence which include a plurality of sequence units in a Booth format. According to both the dynamic ranges of the input data and of the filter coefficients, the configurable connection unit is used to select certain parts of the sequence units for the convolution calculation, so that a dynamic data range is scaleable by the processor. By Booth decoders, the selected sequence units are decoded and multiplied by corresponding filter coefficients stored in the coefficient registers.

Abstract: A digital speech encoder and decoder have particular application to the field of 16 kbps digital communications. In the encoder, a speech signal is processed by a perceptual weighting filter, using a reconstructed speech signal, a reconstructed residual signal, and a set of filter tuning coefficients. A predictive signal, which is generated by a Short Term Predictive (STP) circuit, is subtracted from the signal outputted from the perceptual weighting filter. The difference signal is processed by a coder/decoder circuit to produce a reconstructed error signal, which is added to the predictive signal to form the reconstructed residual signal. A Linear Predictive Coding (LPC) circuit receives the reconstructed residual signal and develops the set of filter tuning coefficients. The set of filter tuning coefficients are outputted to the STP circuit, which also receives the reconstructed residual signal, and thereby generates the predictive signal.