The 821034 is a single-chip, four-channel PCM codec with on-chip filters and a programmable gain setting. This device provides both µ-Law and A-Law companding digital-to-analog and analog-to-digital conversions based on ITU-T G.711 - G.714 specifications. The digital filters in the 821034 provide the necessary transmit and receive filtering for voice telephone circuits to interface with time-division multiplexed systems. The 821034 has a flexible PCM interface with software-selectable timing modes and an independently programmable time slot for each transmit and receive channel. It also integrates the SLIC signaling functions through internal registers. The Codec and SLIC control/status registers are accessed via the serial control interface.