SCN68661

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)
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

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 an asynchronous -in the full- or half-duplex mode.  Special suppor for BISYNC is provided.

The EPCI serializes parallel data characters received from the microprocessor for transmission.  Simultaneously, it can receive serial data and convert it into parallel data characters for input to the microcomputer.

The SCN2661 contains a baud rate generator which can be programmed to either accept an external clock or to generate internal transmit or receive clocks.  Sixteen different baud rates can be selected under program control when operating in the internal clock mode.  Each version of the EPCI (A, B, C) has a different set of baud rates.