xr XR16L2450 2.25V TO 5.5V DUART MAY 2005 REV. 1.1.1 FEATURES GENERAL DESCRIPTION The XR16L2450 (L2450) is a dual universal asyn- 2.25 to 5.5 Volt Operation chronous receiver and transmitter (UART). The 5 Volt Tolerant Inputs XR16L2450 is an improved version of the Pin-to-pin compatible to Exars ST16C2450, ST16C2450 with lower operating voltage and 5 volt ST16C2550, XR16L2550, XR16L2750 and tolerant inputs. The L2450 provides enhanced UART XR16C2850 functions, a modem control interface and data rates up to 1.5 Mbps. Onboard status registers provide the Pin-to-pin compatible to TIs TL16C752B on the 48- user with error indications and operational status. In- TQFP package dependent programmable baud rate generators are 2 independent UART channels provided to select transmit and receive clock rates up Up to 1.5 Mbps data rate with a 24 MHz crystal to 1.5 Mbps. An internal loopback capability allows oscillator or external clock frequency onboard diagnostics. The L2450 is available in a 44- 1 byte Transmit FIFO pin PLCC and 48-pin TQFP packages. The L2450 is fabricated in an advanced CMOS process capable of 1 byte Receive FIFO with error tags operating from 2.25 volt to 5.5 volt power supply with Status report registers 5 volt tolerant inputs. Modem control signals (CTS , RTS , DSR , DTR , RI , CD ) APPLICATIONS Programmable character lengths (5, 6, 7, 8) Portable Appliances with even, odd, or no parity Telecommunication Network Routers Crystal oscillator or external clock input Ethernet Network Routers TTL compatible inputs, outputs Cellular Data Devices Industrial temperature ranges Factory Automation and Process Controls 48-TQFP and 44-PLCC packages FIGURE 1. XR16L2450 BLOCK DIAGRAM 2.25 to 5.5 Volt VCC *5V Tolerant inputs A2:A0 D7:D0 UART Channel A TXA IOR THR IOW UART Regs RHR RXA CSA CSB RTSA , CTSA , Modem I/Os 8-bit Data INTA DTRA , DSRA , BRG Bus CDA , RIA , OP2A INTB Interface TXB RXB UART Channel B RTSB , CTSB , (same as Channel A) DTRB , DSRB , Reset CDB , RIB , OP2B XTAL1 Crystal Osc/Buffer XTAL2 Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com XR16L2450 xr 2.25V TO 5.5V DUART REV. 1.1.1 FIGURE 2. PIN OUT ASSIGNMENT 1 36 RESET D5 D6 2 35 DTRB D7 3 34 DTRA RTSA RXB 4 33 RXA 5 32 OP2A XR16L2450 NC 6 31 NC 48-pin TQFP INTA TXA 7 30 TXB 8 29 INTB 9 28 A0 OP2B CSA 10 27 A1 CSB 11 26 A2 NC 12 25 NC D5 7 39 RESET D6 8 38 DTRB D7 9 37 DTRA RXB 10 36 RTSA 11 35 OP2A RXA XR16L2450 NC 12 34 NC 44-pin PLCC TXA 13 33 INTA TXB 14 32 INTB OP2B 15 31 A0 16 A1 CSA 30 CSB 17 29 A2 Device ORDERING INFORMATION PART NUMBER PACKAGE OPERATING TEMPERATURE RANGE DEVICE STATUS XR16L2450IJ 44-Lead PLCC -40C to +85C Active XR16L2450IM 48-Lead TQFP -40C to +85C Active 2 18 6 XTAL1 48 D4 XTAL1 D4 13 XTAL2 14 47 D3 XTAL2 19 5 D3 IOW 15 46 D2 IOW 20 4 D2 CDB 16 45 D1 CDB 21 3 D1 GND 44 17 D0 GND 22 2 D0 NC 18 43 NC 23 NC 1 NC IOR 19 42 VCC IOR 24 44 VCC DSRB 20 41 RIA 25 DSRB 43 RIA RIB 40 21 CDA RIB 26 42 CDA RTSB 22 39 DSRA RTSB 27 41 DSRA CTSB 23 38 CTSA CTSB 28 40 CTSA NC 24 37 NC