XR16L2752 Datasheet, PDF (1/49 Pages) Exar Corporation – 2.25V TO 5.5V DUART WITH 64-BYTE FIFO

xr
MAY 2005
GENERAL DESCRIPTION
The XR16L2752¹ (2752) is a low voltage dual
universal asynchronous receiver and transmitter
(UART) with 5 Volt tolerant inputs. The device
operates from 2.25 to 5.5 Volt supply range and is
pin-to-pin compatible to Exar’s ST16C2552 and
XR16C2852. The 2752 register set is compatible to
the ST16C2552 and the XR16C2852 enhanced
features. It supports the Exar’s enhanced features of
64 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 diagnostics. Independent programmable
baud rate generators are provided in each channel to
select data rates up to 6.25 Mbps at 5 Volt and 8X
sampling. The 2752 is available in the 44-pin PLCC
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
XR16L2752
2.25V TO 5.5V DUART WITH 64-BYTE FIFO
FEATURES
REV. 1.2.1
• 2.25 to 5.5 Volt Operation
• 5 Volt Tolerant Inputs
• Pin-to-pin compatible to Exar’s ST16C2552 and
XR16C2852
• Larger FIFO version of PC16C552
• Two independent UART channels
■ Reg set compatible to 16C2552 and 16C2852
■ Up to 6.25 Mbps at 5 Volt, 4 Mbps at 3.3 Volt
and 3 Mbps at 2.5 Volt with 8X sampling rate
■ 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
■ Full modem interface
• Alternate Function Register
• Device Identification and Revision
• Crystal oscillator or external clock input
• Industrial and commercial temperature ranges
• 44-PLCC package
FIGURE 1. XR16L2752 BLOCK DIAGRAM
A2:A0
D7:D0
IOR#
IOW#
CS#
CHSEL
INTA
INTB
TXRDYA#
TXRDYB#
MFA#
(OP2A#,
BAUDOUTA#, or
RXRDYA#)
MFB#
(OP2B#,
BAUDOUTB#, or
RXRDYB#)
Reset
8-bit Data
Bus
Interface
*5 Volt Tolerant Inputs
(Except External Clock Input)
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
Modem Control Logic
2.25 V to 5.5 V VCC
GND
TXA (or TXIRA)
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
2752BLK
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com