ST16C450 UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER (UART) September 2003 GENERAL DESCRIPTION PLCC Package The ST16C450 is a universal asynchronous receiver and transmitter. The ST16C450 is an improved ver- sion of the NS16450 UART with higher operating speed and lower access time. A programmable baud rate generator is provided to select transmit and receive clock rates from 50 Bps to 1.5 Mbps. D5 7 39 RESET The ST16C450 on board status registers provides the D6 8 38 -OP1 error conditions, type and status of the transfer D7 9 37 -DTR operation being performed. Included is complete RCLK 10 36 -RTS RX 11 35 -OP2 MODEM control capability, and a processor interrupt N.C. 12 34 N.C. system that may be software tailored to the users ST16C450CJ44 TX 13 33 INT requirements. The ST16C450 provides internal loop- 32 CS0 14 N.C. back capability for on board diagnostic testing. CS1 15 31 A0 The ST16C450 is available in 40 pin PDIP, 44 pin 16 30 -CS2 A1 PLCC, and 48 pin TQFP packages. It is fabricated in -BAUDOUT 17 29 A2 an advanced CMOS process to achieve low drain power and high speed requirements. FEATURES Pin to pin and functionally compatible to the Indus- try Standard 16450 2.97 to 5.5 volt operation 1.5 Mbps transmit/receive operation (24MHz) Programmable word lengths (5, 6, 7, 8) Even, odd, force, or no parity generation and detection Independent transmit and receive control Standard modem interface Low operating current ( 1.2mA typ.) ORDERING INFORMATION Part number Package Operating temperature Device Status ST16C450CP40 40-Lead PDIP 0 C to + 70 C Active. See the ST16C450CQ48 for new designs. ST16C450CJ44 44-Lead PLCC 0 C to + 70 C Active ST16C450CQ48 48-Lead TQFP 0 C to + 70 C Active ST16C450IP40 40-Lead PDIP -40 C to + 85 C Active. See the ST16C450IQ48 for new designs. ST16C450IJ44 44-Lead PLCC -40 C to + 85 C Active ST16C450IQ48 48-Lead TQFP -40 C to + 85 C Active Rev. 4.20 EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 (510) 668-7000 FAX (510) 668-7017 XTAL1 18 6 D4 19 XTAL2 5 D3 -IOW 20 4 D2 21 IOW 3 D1 GND 22 2 D0 23 1 N.C. N.C. -IOR 24 44 VCC 25 43 -RI IOR -DDIS 26 42 -CD 27 41 -DSR CSOUT -AS 28 40 -CTSST16C450 Figure 1, PACKAGE DESCRIPTION, ST16C450 48 Pin TQFP Package 40 Pin DIP Package VCC D0 1 40 D1 2 39 -RI D2 3 38 -CD N.C. 1 36 N.C. D3 4 37 -DSR D5 2 35 RESET -CTS D4 5 36 D6 3 34 -OP1 RESET D5 6 35 -DTR D7 4 33 D6 7 34 -OP1 RCLK 5 32 -RTS D7 8 33 -DTR -OP2 N.C. 6 31 ST16C450CQ48 RCLK 9 32 -RTS RX 7 30 INT TX 8 29 N.C. -OP2 RX 10 31 CS0 9 28 A0 INT TX 11 30 CS1 10 27 A1 CS0 12 29 N.C. A2 -CS2 11 26 CS1 13 28 A0 -BAUDOUT 12 25 N.C. -CS2 14 27 A1 A2 -BAUDOUT 15 26 XTAL1 16 25 -AS XTAL2 17 24 CSOUT -IOW 18 23 -DDIS IOW 19 22 IOR -IOR GND 20 21 Rev. 4.20 2 N.C. 13 48 N.C. 47 XTAL1 14 D4 XTAL2 15 46 D3 -IOW 45 D2 16 IOW 17 44 D1 GND 18 43 D0 42 -IOR 19 VCC IOR 20 41 -RI N.C. 40 -CD 21 -DDIS 22 39 -DSR CSOUT 23 38 -CTS -AS 24 37 N.C. ST16C450CP40