Abstract: A command memory stores commands in memory words. Each command has a label field and an action field. The commands are consolidated to reduce the amount of information stored in the command memory. A control unit interprets the commands and restores the order that was removed by the consolidation. The control unit arranges the action fields as commands in a control word based on information in the label field. When the commands are compressed in the command memory, commands that are not performed in parallel can be stored in the same memory word. Commands that are performed in parallel can be stored in different memory words. The order of the commands in the control word is determined by information in the label field, such as whether the command is performed in parallel with a preceding command.

Abstract: A digital signal processor that is used for echo cancellation computations is disclosed, which includes parallel multiplier/adders, an input signal sample memory, and a plurality of accumulators for temporarily storing the results of the computations performed. Consequently, not all of the computational results have to be saved in an external data memory, which minimizes data transfer bottlenecks and significantly increases the computational efficiency of the digital signal processor. The adaptive filter coefficient updates can thereby be computed much faster, and the adaptive filter coefficients can be copied much faster from one filter to the other. The computational complexity of the digital signal processor is significantly less than that of prior digital signal processors.