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