XR16M2551 HIGH PERFORMANCE LOW VOLTAGE DUART WITH 16-BYTE FIFO AND POWERSAVE FEATURE MAY 2007 REV. 1.0.2 FEATURES GENERAL DESCRIPTION 1.62 to 3.63 Volt Operation 1 The XR16M2551 (M2551) is a high performance dual universal asynchronous receiver and transmitter Pin-to-pin compatible to Exars XR16V2551 and the (UART) with 16 byte TX and RX FIFOs. The device XR16L2551 operates from 1.62 to 3.63 volts and is pin-to-pin Two independent UART channels compatible to the XR16L2551 and XR16V2551. The Register set is 16550 compatible M2551 includes 2 additional capabilities over the XR16M2550: Intel and Motorola data bus selection Data rate of up to 16 Mbps at 3.3 V and a PowerSave mode to minimize the sleep Data rate of up to 12.5 Mbps at 2.5 V current. It supports Exars enhanced features of Data rate of up to 8 Mbps at 1.8V selectable FIFO trigger level, automatic hardware Fractional Baud Rate Generator (RTS/CTS) and software flow control, and a complete modem interface. An internal loopback capability Transmit and Receive FIFOs of 16 bytes allows system diagnostics. Independent Selectable TX and RX FIFO Trigger Levels programmable fractional baud rate generators are Automatic Hardware (RTS/CTS) Flow Control provided in each channel to select data rates up to 16 Automatic Software (Xon/Xoff) Flow Control Mbps at 3.3 Volt and 4X sampling clock. The M2551 is available in 48-pin TQFP and 32-pin QFN Wireless Infrared (IrDA 1.0) Encoder/Decoder packages. Automatic sleep mode with wake-up interrupt NOTE: 1 Covered by U.S. Patent 5,649,122 Full modem interface APPLICATIONS PowerSave Feature reduces sleep current to 15 A Portable Appliances Device Identification and Revision Telecommunication Network Routers Crystal oscillator (up to 24MHz) or external clock (up to 64MHz) input Ethernet Network Routers 48-TQFP and 32-QFN packages Cellular Data Devices Factory Automation and Process Controls FIGURE 1. XR16M2551 BLOCK DIAGRAM 1.62 to 3.63V VCC PwrSave GND A2:A0 D7:D0 UART Channel A IOR (VCC) TXA, RXA, DTRA , IOW (R/W ) 16 Byte TX FIFO UART DSRA , RTSA , Regs CSA (CS ) IR DTSA , CDA , RIA , TX & RX ENDEC CSB (A3) OP2A BRG INTA (IRQ ) 16 Byte RX FIFO INTB (logic 0) TXB, RXB, DTRB , TXRDYA UART Channel B DSRB , RTSB , Intel or TXRDYB (same as Channel A) CTSB , CDB , RIB , Motorola RXRDYA OP2B Data Bus RXRDYB Interface XTAL1 Reset (Reset ) Crystal Osc/Buffer XTAL2 16/68 CLKSEL Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com XR16M2551 HIGH PERFORMANCE LOW VOLTAGE DUART WITH 16-BYTE FIFO AND POWERSAVE FEATURE REV. 1.0.2 FIGURE 2. PIN OUT ASSIGNMENT D6 1 24 RESET 1 24 RESET (Reset) D6 D7 2 23 RTSA 2 23 RTSA D7 RXB 22 IRQ 3 22 INTA RXB 3 XR16M2551 XR16M2551 RXA NC (INTB) 4 21 INTB RXA 4 21 32-pin QFN 32-pin QFN TXA 5 20 A0 TXA 5 20 A0 In 16 (Intel) Mode in 68 (Motorola) Mode TXB 19 A1 6 19 A1 6 TXB A2 VCC 7 18 A2 7 18 CS CSA 8 17 A3 (CSB ) 8 17 16/68 CSB 16/68 GND D5 1 36 RESET D5 1 36 RESET D6 2 35 DTRB D6 2 35 DTRB D7 3 34 DTRA D7 3 34 DTRA 4 33 RTSA 4 33 RTSA RXB RXB OP2A OP2A RXA 5 32 RXA 5 32 XR16M2551 XR16M2551 TXRDYB 6 31 RXRDYA TXRDYB 6 31 RXRDYA 48-pin TQFP 48-pin TQFP TXA 7 30 INTA TXA 7 30 IRQ in 16 (Intel) Mode in 68 (Motorola) Mode TXB 8 29 INTB TXB 8 29 NC 9 28 A0 9 28 A0 OP2B OP2B A1 A1 CSA 10 27 CS 10 27 CSB 11 26 A2 A3 11 26 A2 PWRSAVE 12 25 CLKSEL PWRSAVE 12 25 CLKSEL VCC GND ORDERING INFORMATION PART NUMBER PACKAGE OPERATING TEMPERATURE RANGE DEVICE STATUS XR16M2551IL32 32-Pin QFN -40C to +85C Active XR16M2551IM48 48-Lead TQFP -40C to +85C Active 2 XTAL1 48 D4 13 XTAL2 14 47 D3 PWRSAVE 32 D5 9 IOW 15 46 D2 XTAL1 31 D4 CDB 10 16 45 D1 XTAL2 11 30 D3 GND 17 44 D0 IOW 12 29 D2 RXRDYB 18 43 TXRDYA 13 28 GND D1 IOR 19 42 VCC 14 27 D0 IOR DSRB 20 41 RIA RTSB 15 26 VCC RIB 40 21 CDA CTSB 16 25 CTSA RTSB 39 22 DSRA CTSB 38 23 CTSA 16/68 37 NC 24 XTAL1 13 48 D4 XTAL2 14 47 D3 32 PWRSAVE 9 D5 R/W 15 46 D2 XTAL1 31 D4 10 CDB 16 45 D1 D3 XTAL2 11 30 GND 17 44 D0 D2 R/W 12 29 RXRDYB 18 43 TXRDYA 28 D1 GND 13 NC 19 42 VCC 14 27 D0 VCC (IOR ) DSRB 20 41 RIA 15 26 RTSB VCC RIB 40 21 CDA 16 25 CTSB CTSA RTSB 39 22 DSRA CTSB 38 CTSA 23 16/68 24 37 NC