Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com
XR16M780
1.62V TO 3.63V HIGH PERFORMANCE UART WITH 64-BYTE FIFO
SEPTEMBER 2008
REV. 1.0.0
GENERAL DESCRIPTION
The XR16M7801 (M780) is an enhanced Universal
Asynchronous Receiver and Transmitter (UART) with
64
bytes
of
transmit
and
receive
FIFOs,
programmable transmit and receive FIFO trigger
levels, automatic hardware and software flow control,
and data rates of up to 16 Mbps at 3.3V, 12.5 Mbps at
2.5V and 7.5 Mbps at 1.8V with 4X data sampling
rate.
The Auto RS-485 Half-Duplex Direction control
feature simplifies both the hardware and software for
half-duplex RS-485 applications. In addition, the
Multidrop
mode
with
Auto
Address
detection
increases
the
performance
by
simplifying
the
software routines.
The Independent TX/RX Baud Rate Generator
feature allows the transmitter and receiver to operate
at different baud rates. Power consumption of the
M780 can be minimized by enabling the sleep mode
and PowerSave mode.
The M780 has a 16550 compatible register set that
provide users with operating status and control,
receiver error indications, and modem serial interface
controls. An internal loopback capability allows
onboard diagnostics. The M780 is available in 32-pin
QFN, 48-pin TQFP and 25-pin BGA packages. All
three packages offer both the 16 mode (Intel bus)
interface and the 68 mode (Motorola bus) interface
which
allows
easy
integration
with
Motorola
processors.
NOTE: 1 Covered by U.S. Patent #5,649,122.
FEATURES
Pin-to-pin compatible with XR16L580 in 32-QFN
and 48-TQFP packages
Intel or Motorola Bus Interface select
16Mbps maximum data rate
Programmable TX/RX FIFO Trigger Levels
TX/RX FIFO Level Counters
Independent TX/RX Baud Rate Generator
Fractional Baud Rate Generator
Auto RTS/CTS Hardware Flow Control
Auto XON/XOFF Software Flow Control
Auto RS-485 Half-Duplex Direction Control
Multidrop mode w/ Auto Address Detect
Sleep Mode with Automatic Wake-up
PowerSave mode
Infrared (IrDA 1.0 and 1.1) mode
1.62V to 3.63V supply operation
Crystal oscillator or external clock input
APPLICATIONS
Personal Digital Assistants (PDA)
Cellular Phones/Data Devices
Battery-Operated Devices
Global Positioning System (GPS)
Bluetooth
FIGURE 1. XR16M780 BLOCK DIAGRAM
VC C
XTAL1
XTAL2
C rystal O sc/B uffer
TX , R X ,
RTS #, CTS #,
DTR#, DS R#,
Intel or
Motorola
D ata B us
Interface
UA RT
64 B yte R X F IFO
BR G
IR
E NDE C
TX &
RX
UA R T
R egs
A2:A 0
Pw rS ave
64 B yte TX FIF O
RI#, C D #
R ESET
(R ESET#)
D7:D 0
IO W # (R /W #)
CS #
IN T (IR Q #)
IO R #
GN D
(1.62 to 3.63 V )
16/68#