DESCRIPTION

The Philips Semiconductors SCC2692 Dual Universal Asynchronous Receiver/Transmitter (DUART) which is compatible with the SCN2681. It is a single-chip CMOS-LSI communications device that provides two full-duplex asynchronous receiver/transmitter channels in a single package. It interfaces directly with microprocessors and may be used in a polled or interrupt driven system.

FEATURES

• Dual full-duplex asynchronous receiver/transmitters

• Quadruple buffered receiver data register

• Programmable data format

   – 5 to 8 data bits plus parity

   – Odd, even, no parity or force parity

   – 1, 1.5 or 2 stop bits programmable in 1/16-bit increments

• 16-bit programmable Counter/Timer

• Programmable baud rate for each receiver and transmitter selectable from:

   – 22 fixed rates: 50 to 115.2k baud

   – Non-standard rates to 115.2Kb

   – Non-standard user-defined rate derived from programmable counter/timer

   – External 1X or 16X clock

• Parity, framing, and overrun error detection

• False start bit detection

• Line break detection and generation

• Programmable channel mode

   – Normal (full-duplex)

   – Automatic echo

   – Local loopback

   – Remote loopback

   – Multidrop mode (also called ‘wake-up’ or ‘9-bit’)

• Multi-function 7-bit input port

   – Can serve as clock or control inputs

   – Change of state detection on four inputs

   – Inputs have typically >100k pull-up resistors

• Multi-function 8-bit output port

   – Individual bit set/reset capability

   – Outputs can be programmed to be status/interrupt signals

• Versatile interrupt system

   – Single interrupt output with eight maskable interrupting conditions

   – Output port can be configured to provide a total of up to six separate wire-ORable interrupt outputs

• Maximum data transfer rates: 1X – 1MB/sec, 16X – 125kB/sec

• Automatic wake-up mode for multidrop applications

• Start-end break interrupt/status

• Detects break which originates in the middle of a character

• On-chip crystal oscillator

• Power down mode

• Receiver timeout mode

• Commercial and industrial temperature range versions

• TTL compatible

• Single +5V power supply