xr16l2450im Exar Corporation, xr16l2450im Datasheet
xr16l2450im
Available stocks
Related parts for xr16l2450im
xr16l2450im Summary of contents
Page 1
MAY 2005 GENERAL DESCRIPTION The XR16L2450 (L2450 dual universal asyn- chronous receiver and transmitter (UART). The XR16L2450 is an improved ST16C2450 with lower operating voltage and 5 volt tolerant inputs. The L2450 provides enhanced UART functions, a ...
Page 2
... NC TXA TXB OP2B# CSA# CSB RXB RXA NC TXA TXB OP2B# CSA# CSB# Device ORDERING INFORMATION ART UMBER XR16L2450IJ 44-Lead PLCC XR16L2450IM 48-Lead TQFP XR16L2450 6 48-pin TQFP XR16L2450 12 44-pin PLCC ...
Page 3
REV. 1.1.1 PACKAGE PIN DESCRIPTIONS PIN DESCRIPTIONS 44-PLCC 48-TQFP N AME DATA BUS INTERFACE ...
Page 4
XR16L2450 2.25V TO 5.5V DUART PIN DESCRIPTIONS 44-PLCC 48-TQFP N AME CTSA DTRA DSRA CDA RIA OP2A TXB 14 8 RXB 10 ...
Page 5
REV. 1.1.1 PIN DESCRIPTIONS 44-PLCC 48-TQFP N AME OP2B ANCILLARY SIGNALS XTAL1 18 13 XTAL2 19 14 RESET 39 36 VCC 44 42 GND 22 17 N.C. 1, 12, 23, 6, ...
Page 6
XR16L2450 2.25V TO 5.5V DUART 1.0 PRODUCT DESCRIPTION The XR16L2450 (L2450) integrates the functions of 2 16C450 Universal Asynchrounous Receiver and Transmitter (UART). Each UART is independently controlled having its own set of device configuration registers. The L2450 provides serial ...
Page 7
REV. 1.1.1 2.4 Device Identification and Revision The L2450 provides a Device Identification code and a Device Revision code to distinguish the part from other devices and revisions. To read the identification code from the part required ...
Page 8
XR16L2450 2.25V TO 5.5V DUART F The on-chip oscillator is designed to use an industry standard microprocessor crystal (parallel resonant, fundamental frequency with 10-22 pF capacitance load, ESR of 20-120 ohms and 100 ppm frequency tolerance) connected externally between the ...
Page 9
REV. 1.1 ABLE YPICAL DATA RATES WITH A O Data Rate D 16x UTPUT IVISOR FOR MCR Bit-7=0 Clock (Decimal) 400 2304 2400 384 4800 192 9600 96 19.2k 48 38.4k 24 76.8k 12 153.6k 6 ...
Page 10
XR16L2450 2.25V TO 5.5V DUART 2.11 Receiver The receiver section contains an 8-bit Receive Shift Register (RSR) and 1 byte FIFO or Receive Holding Register (RHR). The RSR uses the 16X clock for timing. It verifies and validates every bit ...
Page 11
REV. 1.1.1 2.12 Internal Loopback The L2450 UART provides an internal loopback capability for system diagnostic purposes. The internal loopback mode is enabled by setting MCR register bit-4 to logic 1. All regular UART functions operate normally. Figure 7 ...
Page 12
XR16L2450 2.25V TO 5.5V DUART 3.0 UART INTERNAL REGISTERS Each of the UART channel in the L2450 has its own set of configuration registers selected by address lines A0, A1 and A2 with CSA# or CSB# selecting the channel. The ...
Page 13
REV. 1.1 ABLE DDRESS EG EAD A2- AME RITE RHR RD Bit THR WR Bit IER RD/ ...
Page 14
XR16L2450 2.25V TO 5.5V DUART 4.3.1 Interrupt Mode Operation When the receive interrupt (IER BIT enabled, the RHR interrupt (see ISR bit-2) status will reflect the following: A. The receive data available interrupts are issued to the ...
Page 15
REV. 1.1.1 4.4.1 Interrupt Generation: • LSR is by any of the LSR bits and 4. • RXRDY is by data byte received in RHR. • TXRDY is by THR empty. • MSR is by any ...
Page 16
XR16L2450 2.25V TO 5.5V DUART LCR[1:0]: TX and RX Word Length Select These two bits specify the word length to be transmitted or received. BIT LCR[2]: TX and RX Stop-bit Length Select The length of stop ...
Page 17
REV. 1.1.1 LCR[6]: Transmit Break Enable When enabled, the Break control bit causes a break condition to be transmitted (the TX output is forced to a “space’, logic 0, state). This condition remains, until disabled by setting LCR bit-6 ...
Page 18
XR16L2450 2.25V TO 5.5V DUART LSR[1]: Receiver Overrun Flag • Logic overrun error (default). • Logic 1 = Overrun error. A data overrun error condition occurred in the receive shift register. This happens when additional data arrives ...
Page 19
REV. 1.1.1 MSR[1]: Delta DSR# Input Flag • Logic change on DSR# input (default). • Logic 1 = The DSR# input has changed state since the last time it was monitored. A modem status interrupt will ...
Page 20
XR16L2450 2.25V TO 5.5V DUART T 8: UART RESET CONDITIONS FOR CHANNEL A AND B ABLE REGISTERS I/O SIGNALS RESET STATE DLM Bits 7-0 = 0xXX DLL Bits 7-0 = 0xXX RHR Bits 7-0 = 0xXX THR Bits 7-0 = ...
Page 21
REV. 1.1.1 ABSOLUTE MAXIMUM RATINGS Power Supply Range Voltage at Any Pin Operating Temperature Storage Temperature Package Dissipation TYPICAL PACKAGE THERMAL RESISTANCE DATA Thermal Resistance (48-TQFP) Thermal Resistance (44-PLCC) ELECTRICAL CHARACTERISTICS DC ELECTRICAL CHARACTERISTICS U : TA=-40 NLESS OTHERWISE ...
Page 22
XR16L2450 2.25V TO 5.5V DUART AC ELECTRICAL CHARACTERISTICS U : TA=-40 NLESS OTHERWISE NOTED LOAD WHERE APPLICABLE S P YMBOL ARAMETER - Crystal Frequency CLK External Clock Low/High Time OSC External Clock Frequency T Address Setup Time ...
Page 23
REV. 1.1 IGURE LOCK IMING CLK EXTERNAL CLOCK IGURE ODEM NPUT UTPUT IOW # Active RTS# Change of state DTR# CD# CTS# DSR# INT IOR# RI# CLK OSC F ...
Page 24
XR16L2450 2.25V TO 5.5V DUART F 10 IGURE ATA US EAD IMING A0-A2 Valid Address T AS CSA#/ CSB# IOR# T RDV D0- IGURE ATA US RITE IMING A0-A2 Valid ...
Page 25
REV. 1.1 IGURE NTERRUPT IMING FOR RX Start D0:D7 Bit INT IOR# (Reading data out of RHR IGURE NTERRUPT IMING FOR TX Start (Unloading) D0:D7 Bit T INT IER[1] enabled INT* ...
Page 26
XR16L2450 2.25V TO 5.5V DUART PACKAGE DIMENSIONS (48 PIN TQFP - Seating Plane Note: The control dimension is the millimeter column SYMBOL α ...
Page 27
REV. 1.1.1 PACKAGE DIMENSIONS (44 PIN PLCC Note: The control dimension is the millimeter column SYMBOL ...
Page 28
... Updated the Data Access Time (T EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a user’ ...
Page 29
TO 5.5V DUART GENERAL DESCRIPTION................................................................................................. 1 A ............................................................................................................................................... 1 PPLICATIONS F ..................................................................................................................................................... 1 EATURES F 1. XR16L2450 B D IGURE LOCK IAGRAM ..................................................................................................................................................... 2 IGURE IN UT SSIGNMENT ................................................................................................................................ 2 ORDERING INFORMATION PACKAGE ...
Page 30
XR16L2450 REV. 1.1 LECTRICAL HARACTERISTICS LECTRICAL HARACTERISTICS Unless otherwise noted: TA=-40o to +85oC, Vcc is 2.25V to 5.5V, .......................................................................... ...................................................................................................................22 P LOAD WHERE APPLICABLE ............................................................................................................................................................... 23 IGURE ...