The DS2164Q ADPCM processor chip is a dedicated digital-signal-processing (DSP) chip that has been optimized to perform adaptive-differential pulse-code modulation (ADPCM) speech compression at three different rates. The chip can be programmed to compress (expand) 64kbps voice data down to (up from) either 32kbps, 24kbps, or 16kbps. The compression to 32kbps follows the algorithm specified by CCITT Recommendation G.726. The DS2164Q can switch compression algorithms on-the-fly. This allows the user to make maximum use of the available bandwidth on a dynamic basis.