The Bt8960 is a full-duplex 2B1Q transceiver based on Rockwell's HDSL technology. It supports Nx64 kbps transmission of more than 18,000 feet over 26 AWG copper telephone wire without repeaters. Small size and low power dissipation make the Bt8960 ideal for line-powered voice pairgain systems capable of providing four or six clear 64 kbps channels. The Bt8960 is a highly integrated device that includes all of the active circuitry needed for a complete 2B1Q transceiver. In the receive portion of the Bt8960, a variable gain amplifier optimizes the signal level according to the dynamic range of the analog-to-digital converter. Once the signal is digitized, sophisticated adaptive echo cancellation, equalization, and detection DSP algorithms reproduce the originally transmitted far-end signal. In the transmitter, the transmit source and scrambler operation is programmable via the microcomputer interface. A highly linear digital-to-analog converter with programmable gain, sets the transmission power for optimal performance. A pulse-shaping filter and a low distortion line driver generate the signal characteristics needed to drive a large range of subscriber lines at low-bit error rates. Startup and performance monitoring operations are controlled via the microprocessor interface. C-language source code supporting these operations is supplied under a no-fee license agreement from Rockwell. The Bt8960 includes a glueless interface to both Intel and Motorola microprocessors.