"The MT89L85 Enhanced Digital Switch device is an upgraded 3-volt version of the MT8985 Digital Switch. It is pin compatible with the MT8985 and retains all of the MT8985's functionality. The enhanced digital swtich is designed for switching PCM-encoded voice or data, under microprocessor control, in digital exchanges, PBXs and any ST-BUS/MVIP? environment. It provides simultaneous connections for up to 256 64 kbps channels. Each of the eight serial inputs and outputs consist of 32 64 kbps channels multiplexed to form a 2048 kbps stream. As the main function in switching applications, the device provides per-channel selection between variable or constant throughput delays. The constant throughput delay feature allows grouped channels such as ISDN H0 to be switched through the device maintaining its sequence integrity. The MT89L85 is ideal for medium sized mixed voice/data switch and voice processing applications."