The Philips Semiconductors SC68C562 is a CMOS dual universal serial communications controller (CDUSCC) that provides two independent, multi-protocol, full-duplex receiver/transmitter channels in a single package. It supports bit-oriented and character-oriented synchronous data link controls as well as asynchronous protocols. The SC68C562 interfaces to the 68000 MPUs via asynchronous bus control signals and is capable of program-polled, interrupt driven, block-move or DMA data transfers. It is hardware and software compatible with the SCN68562 (NMOS version). Each channel of the SC68C562 consists of a receiver, a transmitter, a 16-bit multifunction counter/timer, a digital phase-locked loop (DPLL), a parity/CRC generator and checker, and associated control circuits. The two channels share a common bit rate generator (BRG), operating directly from a crystal or an external clock.