STMicroelectronics MK68564
The MK68564 SIO (Serial Input Output) is a dualchannel, multi-function peripheral circuit, designed to satisfy a wide variety of serial data communications requirements in microcomputer systems. Its basic function is a serial-to-parallel, parallel-to-serial converter/controller ; however within that role, it is systems software configurable so that its ”personality” may be optimized for any given serial data communications application. The MK68564 is capable of handling asynchronous protocols, synchronous byte-oriented protocols (such as IBM Bisync), and synchronous bit-oriented protocols (such as HDLC and IBM SDLC).