The 821034 is a single-chip, four channel PCM CODEC with onchip filters and programmable gain setting. This device provides both m-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 IDT821034 provides the necessary transmit and receive filtering for voice telephone circuit to interface with time-division multiplexed systems. The IDT821034 has a flexible PCM interface with software selectable timing modes and 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.