PRELIMINARY
XR16V2552
HIGH PERFORMANCE DUART WITH 16-BYTE FIFO
JUNE 2006
REV. P1.0.0
FEATURES
GENERAL DESCRIPTION
• 2.25 to 3.6 Volt Operation
• 5 Volt Tolerant Inputs
1
The XR16V2552 (V2552) is a high performance dual
universal asynchronous receiver and transmitter
(UART) with 16 byte TX and RX FIFOs. The device
operates from 2.25 to 3.6 volts with 5 Volt tolerant
inputs and is pin-to-pin compatible to Exar’s
ST16C2552 and XR16L2552. The V2552 register set
is compatible to the ST16C2552 and the XR16L2552.
It supports the Exar’s enhanced features of
selectable FIFO trigger level, automatic hardware
(RTS/CTS) and software (Xon/Xoff) flow control, and
a complete modem interface. Onboard registers
provide the user with operational status and data
error flags. An internal loopback capability allows
system diagnostics. Independent programmable
baud rate generators are provided in each channel to
select data rates up to 16 Mbps at 3.3 Volt with 4X
sampling clock. The V2552 is available in 44-pin
PLCC and 32-pin QFN packages.
• Pin-to-pin compatible to Exar’s XR16L2552 in the
44-PLCC package
• Two independent UART channels
■ Register set identical to 16V2550
■ Data rate of up to 16 Mbps at 3.3 V, and
12.5 Mbps at 2.5 V with 4X sampling rate
■ Fractional Baud Rate Generator
■ Transmit and Receive FIFOs of 16 bytes
■ Selectable TX and RX FIFO Trigger Levels
■ Automatic Hardware (RTS/CTS) Flow Control
■ Automatic Software (Xon/Xoff) Flow Control
■ Wireless Infrared (IrDA 1.0) Encoder/Decoder
■ Automatic sleep mode
NOTE: 1 Covered by U.S. Patent #5,649,122
■ Full modem interface
APPLICATIONS
• Alternate Function Register
• Portable Appliances
• Device Identification and Revision
• Telecommunication Network Routers
• Ethernet Network Routers
• Cellular Data Devices
• Crystal oscillator (up to 32MHz) or external clock
(up to 64MHz) input
• 44-PLCC and 32-QFN packages
• Factory Automation and Process Controls
FIGURE 1. XR16V2552 BLOCK DIAGRAM
* 5 Volt Tolerant Inputs
2.25 to 3.6 Volt VCC
A2:A0
D7:D0
GND
IOR#
IOW#
UART Channel A
TXA, RXA, DTRA#,
16 Byte TX FIFO
CS#
UART
DSRA#, RTSA#,
DTSA#, CDA#, RIA#,
OP2A#
Regs
IR
ENDEC
CHSEL
TX & RX
8-bit Data
Bus
Interface
INTA
INTB
BRG
16 Byte RX FIFO
TXRDYA#
TXRDYB#
RXRDYA#
RXRDYB#
TXB, RXB, DTRB#,
DSRB#, RTSB#,
CTSB#, CDB#, RIB#,
OP2B#
UART Channel B
(same as Channel A)
Reset
XTAL1
XTAL2
Crystal Osc/Buffer
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com