xr
FEBRUARY 2005
XR16C2852
2.97V TO 5.5V DUAL UART WITH 128-BYTE FIFOS
REV. 2.1.1
GENERAL DESCRIPTION
The XR16C2852
1
(2852) is a dual universal
asynchronous receiver and transmitter (UART). The
device operates at 2.97V to 5.5V and is pin-to-pin
compatible to Exar’s ST16C2552 and XR16L2752.
The 2852 register set is compatible to the
ST16C2552 and the XR16L2752 enhanced features.
It supports the Exar’s enhanced features of 128 bytes
of TX and RX FIFOs, 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 diagnotics. Independent programmable baud
rate generators are provided in each channel to
select data rates up to 3.125 Mbps at 5V. The 2852 is
available in the 44-pin PLCC package.
N
OTE
:
1 Covered by U.S. Patent #5,649,122 and #5,949,787
FEATURES
Added feature in devices with a top mark date code of
"F2 YYWW" and newer:
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5V tolerant inputs
0 ns address hold time (T
AH
)
•
Pin-to-pin compatible to Exar’s ST16C2552 and
XR16L2752
•
Improved version of PC16C552
•
Two independent UART channels
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APPLICATIONS
•
Portable Appliances
•
Telecommunication Network Routers
•
Ethernet Network Routers
•
Cellular Data Devices
•
Factory Automation and Process Controls
Register set compatible to 16C550
Up to 3 Mbps at 5V, and 2 Mbps at 3.3V
Transmit and Receive FIFOs of 128 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
Wireless Infrared (IrDA 1.0) Encoder/Decoder
Automatic sleep mode
•
Alternate Function Register
•
Device Identification and Revision
•
Crystal oscillator or external clock input
•
2.97 to 5.5 volt operation
•
Industrial and commercial temperature ranges
F
IGURE
1. XR16C2852 B
LOCK
D
IAGRAM
A2:A0
D7:D0
IOR#
IOW#
CS#
CHSEL
INTA
INTB
TXRDYA#
TXRDYB#
MFA#
(OP2A#,
BAUDOUTA#, or
RXRDYA#)
2.97V to 5.5V VCC
GND
UART Channel A
UART
Regs
BRG
8-bit Data
Bus
Interface
128 Byte TX FIFO
TX & RX
IR
ENDEC
RXA (or RXIRA)
TXB (or TXIRB)
RXB (or RXIRB)
XTAL1
XTAL2
CTS#A/B, RI#A/B,
CD#A/B, DSR#A/B
DTR#A/B, RTS#A/B
TXA (or TXIRA)
128 Byte RX FIFO
UART Channel B
(same as Channel A)
MFB#
(OP2B#,
BAUDOUTB#, or
RXRDYB#)
Crystal Osc/Buffer
Modem Control Logic
Reset
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
EXAR [ EXAR CORPORATION ]
