PRELIMINARY
XR16M2750
HIGH PERFORMANCE DUART WITH 64-BYTE FIFO
JUNE 2007
REV. P1.0.0
FEATURES
GENERAL DESCRIPTION
• 1.62 to 3.6 Volt Operation
1
The XR16M2750 (M2750) is a high performance
dual universal asynchronous receiver and transmitter
(UART) with 64 byte TX and RX FIFOs. The device
operates from 1.62 to 3.6 volts and is pin-to-pin
compatible to Exar’s ST16C2550 and XR16V2750.
The M2750 register set is identical to the XR16V2750
and is compatible to the ST16C2550 and the
XR16C2850 enhanced features. It supports the
Exar’s enhanced features of programmable FIFO
trigger level and FIFO level counters, automatic
hardware (RTS/CTS) and software flow control,
automatic RS-485 half duplex direction control output
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 8 Mbps at 3.3 Volt and 8X
sampling clock. The M2750 is available in 48-pin
TQFP and 32-pin QFN packages.
• Pin-to-pin compatible to Exar’s XR16V2750 and
TI’s TL16C752B in the 48-TQFP package
• Two independent UART channels
■ Register set compatible to XR16V2750
■ Data rate of up to 8 Mbps at 3.3 V, 6.25 Mbps
at 2.5 V and 4 Mbps at 1.8 V with 8X sampling
rate
■ Fractional Baud Rate Generator
■ Transmit and Receive FIFOs of 64 bytes
■ Programmable TX and RX FIFO Trigger Levels
■ Transmit and Receive FIFO Level Counters
■ Automatic Hardware (RTS/CTS) Flow Control
■ Selectable Auto RTS Flow Control Hysteresis
■ Automatic Software (Xon/Xoff) Flow Control
■ Automatic RS-485 Half-duplex Direction
Control Output via RTS#
NOTE: 1 Covered by U.S. Patent #5,649,122
■ Wireless Infrared (IrDA 1.0) Encoder/Decoder
■ Automatic sleep mode
APPLICATIONS
■ Full modem interface
• Portable Appliances
• Device Identification and Revision
• Telecommunication Network Routers
• Ethernet Network Routers
• Crystal oscillator (up to 32MHz) or external clock
(upto 64MHz) input
• Cellular Data Devices
• 48-TQFP and 32-QFN packages
• Factory Automation and Process Controls
FIGURE 1. XR16M2750 BLOCK DIAGRAM
1.62 to 3.6 Volt VCC
A2:A0
D7:D0
GND
IOR#
IOW#
UART Channel A
TXA, RXA, DTRA#,
64 Byte TX FIFO
CSA#
CSB#
UART
DSRA#, RTSA#,
DTSA#, CDA#, RIA#,
OP2A#
Regs
IR
ENDEC
TX & RX
8-bit Data
Bus
Interface
INTA
INTB
BRG
64 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
2750BLK
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com