DESCRIPTION

The Epic Ei88C681/Ei68C681 DUART Dual Universal Asynchronous Receiver and Transmitter is a data communication device that provides two fully independent full duplex asynchronous communication channels in a single package. The DUART is designed for use in microprocessor based systems and may be used in a polled or interrupt driven environment.

FEATURES

? Full duplex, dual channel asynchronous

receiver and transmitter

? Quadruple-buffered receiver and transmitter

? Stop bits programmable in 1/16-bit increments

? Internal bit rate generator with 23 bit rates

? Independent bit rate selection for each Rx

and Tx

? Maximum bit rate: 1 x clock - 2 Mb/sec., 16

x clock- 250 Kb/sec.

? Normal, auto-echo, local loop-back and

remote loop-back modes

? Multi-function 16-bit counter/timer

? Interrupt output with 8 maskable interrupting

conditions

? Interrupt vector output on acknowledge

? Programmable interrupt daisy chain

? Up to 15 I/O pins (depending on package

and version)

? Multidrop mode compatible with 8051 ninebit mode

? On-chip oscillator for crystal

? Stand-by mode to reduce operating power

? Advanced CMOS low power technology