XR16M2751_07 Datasheet, PDF (1/53 Pages) Exar Corporation – 1.62V TO 3.63V HIGH PERFORMANCE DUART WITH 64-BYTE FIFO

XR16M2751
1.62V TO 3.63V HIGH PERFORMANCE DUART WITH 64-BYTE FIFO
AUGUST 2007
REV. 1.0.0
GENERAL DESCRIPTION
The XR16M2751¹ (M2751) 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 3.63 volts and is pin-to-pin and
software compatible to Exar’s XR16V2751. The
device includes 2 additional capabilities over the
XR16M2750: Intel and Motorola data bus selection
and a “PowerSave” mode to further reduce sleep
current to a minimum during sleep mode. 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. An internal
loopback capability allows system diagnostics.
Independent programmable fractional 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 M2751 is available in a 48-pin TQFP
package.
NOTE: 1 Covered by U.S. Patent #5,649,122 and #5,949,787
APPLICATIONS
• Portable Appliances
• Telecommunication Network Routers
• Ethernet Network Routers
• Cellular Data Devices
• Factory Automation and Process Controls
FEATURES
• 1.62 to 3.63 Volt Operation
• Pin-to-pin compatible to Exar’s XR16V2751 in the
48-TQFP package
• Two independent UART channels
■ Data rate of up to 8 Mbps at 3.3 V
■ Data rate of up to 6.25 Mbps at 2.5 V
■ Data rate of up to 4 Mbps at 1.8 V
■ 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#
■ Wireless Infrared (IrDA 1.0) Encoder/Decoder
■ Automatic sleep mode with wake-up interrupt
■ Full modem interface
• PowerSave Feature reduces sleep current to 15 µA
• Device Identification and Revision
• Crystal oscillator (up to 24MHz) or external clock
(up to 64MHz) input
• 48-TQFP package
FIGURE 1. XR16M2751 BLOCK DIAGRAM
PwrSave
A2:A0
D7:D0
IOR# (VCC)
IOW# (R/W#)
CSA# (CS#)
CSB# (A3)
INTA (IRQ#)
INTB (logic 0)
TXRDYA#
TXRDYB#
RXRDYA#
RXRDYB#
Reset (Reset#)
16/68#
CLKSEL
HDCNTL#
Intel or
Motorola
Data Bus
Interface
UART Channel A
UART
Regs
BRG
64 Byte TX FIFO
TX & RX
IR
ENDEC
64 Byte RX FIFO
UART Channel B
(same as Channel A)
Crystal Osc/Buffer
1.62 to 3.6V VCC
GND
TXA, RXA, DTRA#,
DSRA#, RTSA#,
DTSA#, CDA#, RIA#,
OP2A#
TXB, RXB, DTRB#,
DSRB#, RTSB#,
CTSB#, CDB#, RIB#,
OP2B#
XTAL1
XTAL2
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com