NPI - Exar - XR88C681 CMOS Dual Channel UART (DUART)

XR88C681 XR88C681 CMOS Dual Channel UART (DUART)

General Description:

The EXAR Dual Universal Asynchronous Receiver and Transmitter (DUART) is a data communications 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. The XR88C681 XR88C681 device offers a single IC solution for the 8080/85, 8086/88, Z80, Z8000, 68xx and 65xx microprocessor families.

TheDUART is fabricated using advanced two layermetal, with a high performance density EPI/CMOS 1.8_process to provide high performance and low power consumption, and is packaged in a 40 pin PDIP, a 28 pin PDIP, and a 44 pin PLCC.

Features:

• Two Full Duplex, Independent Channels
• Asynchronous Receiver and Transmitter
• Quadruple-Buffered Receivers and Dual Buffered Transmitters

• Programmable Stop Bits in 1/16 Bit Increments
• Internal Bit Rate Generators with More than 23 Bit Rates
• Independent Bit Rate Selection for Each Transmitter and Receiver
• External Clock Capability
• Maximum Bit Rate: 1X Clock - 1Mb/s, 16X Clock -125kb/s
• Normal, AUTOECHO, Local LOOPBACK and Remote LOOPBACK Modes
• Multi-function 16 Bit Counter/Timer
• Interrupt Output with Eight Maskable Interrupt Conditions
• Interrupt Vector Output on Acknowledge (40 Pin DIPand 44 Pin PLCC Packages Only)
• Programmable Interrupt Daisy Chain
• 8 General Purpose Outputs (40 Pin DIP and 44 Pin PLCC Packages Only)
• 7 General Purpose Inputs with Change of States
• Multi-Drop Mode Compatible with 8051 Nine Bit Mode
• On-Chip Oscillator for Crystal
• Standby Mode to Reduce Operating Power
• Compatible with the Motorola MC2681 and Signetics SCC2692 SCC2692 devices
• Advanced CMOS Low Power Technology
• Detectors on Inputs (40 Pin DIP and 44 Pin PLCC Packages Only)