DESCRIPTION
The Philips Semiconductors SCN68562 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 SCN68562 interfaces to the 68000 MPUs via asynchronous bus control signals and is capable of program-polled, interrupt driven, block-move or DMA data transfers. The operating mode and data format of each channel can be programmed independently.

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 4MHz 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
    – Compatible with the Philips Semiconductors SCB68430 Direct Memory Access Interface (DMAI) and other DMA controllers
    – Single- or dual-address dual transfers
    – Half- or full-duplex operation
    – Automatic frame termination on counter/timer terminal count or DMA DONE
• Interrupt capabilities
    – Daisy chain option
    – 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 I/O pins per channel
    – CTS and DCD programmable autoenables 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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