DESCRIPTION The Philips Semiconductors SCN26562 Dual Universal Serial Communications Controller (DUSCC) is a single-chip MOS-LSI communications device that provides two independent, multi-protocol, full-duplex receiver/transmitter channels in a single package. It supports bit-oriented and character-oriented (byte count and byte control) synchronous data link controls as well as asynchronous protocols. The SCN26562 interfaces to synchronous bus MPUs and is capable of program-polled, interrupt driven, block-move or DMA data transfers. FEATURES General Features • Dual full-duplex synchronous/asynchronous receiver and transmitter • Multiprotocol operation – BOP: HDLC/ADCCP, SDLC, SDLC loop, X.25 or X.75 link level, etc. – COP: BISYNC, DDCMP – ASYNC: 5–8 bits plus optional parity • Four character receiver and transmitter FIFOs • 0 to 4Mbit/sec data rate • Programmable bit rate for each receiver and transmitter selectable from: – 16 fixed rates: 50 to 38.4k baud – One user-defined rate derived from programmable counter/timer – External 1X or 16X clock – Digital phase-locked loop • Parity and FCS (frame check sequence LRC or CRC) generation and checking • Programmable data encoding/decoding: NRZ, NRZI, FM0, FM1, Manchester • Programmable channel mode: full- and half-duplex, auto-echo, or local loopback • Programmable data transfer mode: polled, interrupt, DMA, wait • DMA interface – Single- or dual-address dual transfers – Half- or full-duplex operation – Automatic frame termination on counter/timer terminal count or DMA EOPN input • Interrupt capabilities – Vector output (fixed or modified by status) – Programmable internal priorities – Maskable interrupt conditions • Multi-function programmable 16-bit counter/timer – Bit rate generator – Event counter – Count received or transmitted characters – Delay generator – Automatic bit length measurement • Modem controls – RTS, CTS, DCD, and up to four general purpose pins per channel – CTS and DCD programmable auto-enables for Tx and Rx – Programmable interrupt on change of CTS or DCD • On-chip oscillator for crystal • TTL compatible • Single +5V power supply
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