The D85C30 - (Serial Communication Controller) is a dual channel USART (Universal Synchronous/Asynchronous Receiver/Transmitter) device, designed for use with 8 and 16-bit microprocessors. It functions as serial-to-parallel, parallel-to-serial converter/controller and can be software-configured to satisfy a wide variety of serial communications applications. The device contains a variety of new, sophisticated internal functions, including on-chip baud rate generators. The D85C30 handles asynchronous formats, synchronous byte-oriented protocols, such as IBM® Bisync, and synchronous bit-oriented protocols, like HDLC and IBM SDLC. This versatile device supports virtually any serial data transfer application (telecommunication, LAN, etc.). The device can generate and check CRC codes in any synchronous mode and can be programmed to check data integrity in various modes. The D85C30 has also facilities for modem control in both channels.