DESCRIPTION
The Philips Semiconductors SCN2661 EPCI is a universal synchronous/asynchronous data communications controller chip that is an enhanced version of the SCN2651. It interfaces easily to all 8-bit and 16-bit microprocessors and may be used in a polled or interrupt driven system environment. The SCN2661 accepts programmed instructions from the microprocessor while supporting many serial data communications disciplines —synchronous and asynchronous — in the full- or half-duplex mode. Special support for BISYNC is provided.

FEATURES
• Synchronous operation
    – 5- to 8-bit characters plus parity
    – Single or double SYN operation
    – Internal or external character synchronization
    – Transparent or non-transparent mode
    – Transparent mode DLE stuffing (Tx) and detection (Rx)
    – Automatic SYN or DLE-SYN insertion SYN, DLE and DLESYN stripping
    – Odd, even, or no parity
    – Local or remote maintenance loopback mode
    – Baud rate: DC to 1Mbps (1X clock)
• Asynchronous operation
    – 5- to 8-bit characters plus parity
    – 1, 1-1/2 or 2 stop bits transmitted
    – Odd, even, or no parity
    – Parity, overrun and framing error detection
    – Line break detection and generation
    – False start bit detection
    – Automatic serial echo mode (echoplex)
    – Local or remote maintenance loopback mode
    – Baud rate: DC to 1Mbps (1X clock) DC to 62.5kbps (16X clock) DC to 15.625kbps (64X clock)

OTHER FEATURES
• Internal or external baud rate clock
• 3 baud rate sets
• 16 internal rates for each set
• Double-buffered transmitter and receiver
• Dynamic character length switching
• Full- or half-duplex operation
• TTL compatible inputs and outputs
• RxC and TxC pins are short-circuit protected
• Single +5V power supply
• No system clock required

APPLICATIONS
• Intelligent terminals
• Network processors
• Front-end processors
• Remote data concentrators
• Computer-to-computer links
• Serial peripherals
• BISYNC adaptors