A programmable modem (20) for processing a waveform includes a general purpose processor (GPP) engine (34) and special purpose programmable signal processing engines (22) in communication with the GPP engine (34). Each of the special purpose engines (22) executes a special purpose software program (80) to process a portion of the waveform under one of a plurality of communications standards in response to control signals from the GPP engine (34). A power manager engine (56) is in communication with the GPP engine (34) and the signal processing engines (22). The power manager engine (56) responds to the control signals from the GPP engine (34) to power currently used ones of the special purpose engines (22) and to discontinue power to unused ones of the special purpose engines (22). The programmable modem is implemented on a single CMOS integrated circuit (66).