GENERAL DESCRIPTION
   The XR17C1521 (152) is a monolithic dual PCI Bus Universal Asynchronous Receiver and Transmitter (UART) in Exar’s PCI Bus UART family. The device is designed to meet today’s 32-bit PCI Bus and high bandwidth requirement in communication systems.

FEATURES
• High Performance Dual PCI UART
• PCI Bus 2.2 Target Interface Compliance
• 5V PCI Bus Compliant up to 33MHz Clock
• 32-bit PCI Bus Interface with EEPROM Interface
• A Global Interrupt Source Register for both UARTs
• Data Transfer in Byte, Word and Double-word
• Data Read/Write Burst Operation
• Each UART is independently controlled with:
   • 16C550 Compatible 5G Register Set
   • 64-byte Transmit and Receive FIFOs
   • Transmit and Receive FIFO Level Counters
   • Automatic RTS/CTS or DTR/DSR Flow Control
   • Automatic Xon/Xoff Software Flow Control
   • Automatic RS485 Half-duplex Control Output with
      16 Selectable Turn-around Delay
   • Infrared (IrDA 1.0) Data Encoder/Decoder
   • Programmable Data Rate with Prescaler
   • Up to 6.25 Mbps Serial Data Rate at 5V and 8X
      Sampling
• Eight Multi-Purpose Inputs/outputs
• A General Purpose 16-bit Timer/Counter
• Sleep Mode with Automatic Wake-up Indicator
• Same package and pinout as the XR17D152
   (14x14x1.0mm TQFP package)

APPLICATIONS
• Network Management
• Factory Automation and Process Control
• Ethernet Network to Serial Ports
• Point-of-Sale Systems
• Remote Access Servers
• Multi serial ports RS-232/RS-422/RS-485 Cards