GENERAL DESCRIPTION
   The XR16C2552 (2552) is a dual universal asynchronous receiver and transmitter (UART). The XR16C2552 is an improved version of the PC16552 UART. The 2552 provides enhanced UART functions with 16 byte FIFOs, a modem control interface, and data rates up to 4 Mbps. Onboard status registers provide the user with error indications and operational status. System interrupts and modem control features may be tailored by external software to meet specific user requirements. 

FEATURES
● 2.97 volt to 5.5 volt operation
● 5 volt tolerant inputs
● Pin-to-pin and functionally compatible to National
   PC16552 and Exar’s XR16L2752 and XR16C2852
● 4 Mbps transmit/receive operation (64 MHz
   External Clock Frequency)
● 2 Independent UART Channels
   ■ Register Set Compatible to 16C550
   ■ 16 byte Transmit FIFO to reduce the bandwidth
      requirement of the external CPU
   ■ 16 byte Receive FIFO with error tags to reduce
      the bandwidth requirement of the external CPU
   ■ 4 selectable RX FIFO Trigger Levels
   ■ Fixed Transmit FIFO interrupt trigger level
   ■ Full Modem Interface (CTS#, RTS#, DSR#,
      DTR#, RI#, CD#)
● DMA operation and DMA monitoring via TXRDY#
   and RXRDY# pins
● UART internal register sections A & B may be
   written to concurrently
● Multi-Function output allows more package
   functions with few I/O pins
● Programmable character lengths (5, 6, 7, 8) with
   even, odd, or no parity
● Crystal oscillator or external clock input

APPLICATIONS
● Portable Appliances
● Telecommunication Network Routers
● Ethernet Network Routers
● Cellular Data Devices
● Factory Automation and Process Controls