xr ST16C1450 2.97V TO 5.5V UART AUGUST 2005 REV. 4.2.1 FEATURES GENERAL DESCRIPTION Pin and functionally compatible to SSI 73M1550/ The ST16C1450 is a universal asynchronous 2550 receiver and transmitter (UART). The 1450 is foot print compatible to the SSI 73M1550 and SSI 1 byte Transmit FIFO (THR) 73M2550 UART with one byte FIFO and higher 1 byte Receive FIFO with error tags (RHR) operating speed and lower access time. The 1450 Four levels of prioritized interrupts provides enhanced UART functions with a modem control interface, independent programmable baud Modem Control Signals (CTS , RTS , DSR , rate generators with clock rates to 1.5 Mbps. On DTR , RI , CD ) board status registers provide the user with error Programmable character lengths (5, 6, 7, 8) with indications and operational status. System interrupts even, odd or no parity and modem control features may be tailored by Crystal or external clock input external software to meet specific user requirements. An internal loop-back capability allows on board 1.5 Mbps Transmit/Receive operation (24 MHz) diagnostics. The 1450 is available in a 28-pin PLCC with programmable clock control and 48-pin TQFP packages. The baud rate generator Power Down Mode (50 uA at 3.3 V, 200 uA at 5 V) can be configured for either crystal or external clock Software controllable reset output input. The 48-pin TQFP package provides a buffered reset output that can be controlled through user 2.97 to 5.5 Volt operation software. The 1450 is fabricated in an advanced APPLICATIONS CMOS process to achieve low drain power and high speed requirements. The ST16C1450 is not Battery Operated Electronics compatible with the industry standard 16450 and will Internet Appliances not work with the standard serial port driver in MS Windows (see pages 12-13 for details). For a MS Handheld Terminal Windows compatible UART, see the ST16C450. Personal Digital Assistants Cellular Phones DataPort FIGURE 1. BLOCK DIAGRAM THR A2:A0 Transmitter TX D7:D0 IOR DTR , RTS IOW UART Modem Control Signals Configuration DSR , CTS , Regs CD , RI Data Bus CS Interface RX Receiver INT RHR Baud Rate Generator RESET RST XTAL1/CLK Crystal Osc/Buffer XTAL2 Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com ST16C1450 xr 2.97V TO 5.5V UART REV. 4.2.1 FIGURE 2. ST16C1450 PINOUTS 48-TQFP PACKAGE N.C. 1 36 N.C. N.C. 2 35 N.C. 3 34 D4 CTS D5 4 33 RESET D6 5 32 DTR NOTE: PINOUTS NOT TO SCALE. D7 6 31 RTS ST16C1450CQ48 ACTUAL SIZE OF TQFP PACKAGE RX 7 30 A0 IS SMALLER THAN PLCC PACKAGE. TX 8 29 N.C. 9 28 A1 CS N.C. 10 27 A2 N.C. 11 26 N.C. N.C. 12 25 N.C. 28-PLCC PACKAGES D4 CTS 5 25 D5 RESET 6 24 D6 DTR 7 23 D7 RTS 8 ST16C1450CJ28 22 RX A0 9 21 TX A1 10 20 CS A2 11 19 ORDERING INFORMATION OPERATING PART NUMBER PACKAGE TEMPERATURE DEVICE STATUS RANGE ST16C1450CJ28 28-Lead PLCC 0C to +70C Active ST16C1450CQ48 48-Lead TQFP 0C to +70C Active ST16C1450IJ28 28-Lead PLCC -40C to +85C Active ST16C1450IQ48 48-Lead TQFP -40C to +85C Active 2 48 N.C. N.C. 13 47 D3 N.C. 14 XTAL1 15 46 D2 XTAL2 16 45 D1 N.C. IOW 17 44 43 D0 N.C. 18 GND 42 N.C. 19 IOR 20 41 VCC RI 21 40 CD RST 22 39 DSR 38 N.C. INT 23 37 N.C. N.C. 24 12 4 D3 XTAL1 D2 XTAL2 13 3 IOW 14 2 D1 GND 15 1 D0 16 28 VCC IOR CD RI 17 27 INT 18 26 DSR