XR16M2751 1.62V TO 3.63V HIGH PERFORMANCE DUART WITH 64-BYTE FIFO AUGUST 2007 REV. 1.0.0 FEATURES GENERAL DESCRIPTION 1.62 to 3.63 Volt Operation 1 The XR16M2751 (M2751) is a high performance dual universal asynchronous receiver and transmitter Pin-to-pin compatible to Exars XR16V2751 in the (UART) with 64 byte TX and RX FIFOs. The device 48-TQFP package operates from 1.62 to 3.63 volts and is pin-to-pin and Two independent UART channels software compatible to Exars XR16V2751. The Data rate of up to 8 Mbps at 3.3 V device includes 2 additional capabilities over the XR16M2750: Intel and Motorola data bus selection Data rate of up to 6.25 Mbps at 2.5 V and a PowerSave mode to further reduce sleep Data rate of up to 4 Mbps at 1.8 V current to a minimum during sleep mode. It supports Fractional Baud Rate Generator the Exars enhanced features of programmable FIFO Transmit and Receive FIFOs of 64 bytes trigger level and FIFO level counters, automatic hardware (RTS/CTS) and software flow control, Programmable TX and RX FIFO Trigger Levels automatic RS-485 half duplex direction control output Transmit and Receive FIFO Level Counters and a complete modem interface. An internal Automatic Hardware (RTS/CTS) Flow Control loopback capability allows system diagnostics. Selectable Auto RTS Flow Control Hysteresis Independent programmable fractional baud rate generators are provided in each channel to select Automatic Software (Xon/Xoff) Flow Control data rates up to 8 Mbps at 3.3 Volt and 8X sampling Automatic RS-485 Half-duplex Direction clock. The M2751 is available in a 48-pin TQFP Control Output via RTS package. Wireless Infrared (IrDA 1.0) Encoder/Decoder NOTE: 1 Covered by U.S. Patent 5,649,122 and 5,949,787 Automatic sleep mode with wake-up interrupt APPLICATIONS Full modem interface Portable Appliances PowerSave Feature reduces sleep current to 15 A Telecommunication Network Routers Device Identification and Revision Ethernet Network Routers Crystal oscillator (up to 24MHz) or external clock (up to 64MHz) input Cellular Data Devices 48-TQFP package Factory Automation and Process Controls FIGURE 1. XR16M2751 BLOCK DIAGRAM 1.62 to 3.6V VCC PwrSave GND A2:A0 D7:D0 UART Channel A IOR (VCC) TXA, RXA, DTRA , IOW (R/W ) 64 Byte TX FIFO UART DSRA , RTSA , CSA (CS ) Regs IR DTSA , CDA , RIA , TX & RX ENDEC CSB (A3) OP2A BRG INTA (IRQ ) 64 Byte RX FIFO INTB (logic 0) TXB, RXB, DTRB , TXRDYA Intel or UART Channel B DSRB , RTSB , TXRDYB Motorola (same as Channel A) CTSB , CDB , RIB , RXRDYA Data Bus OP2B RXRDYB Interface XTAL1 Reset (Reset ) Crystal Osc/Buffer XTAL2 16/68 CLKSEL HDCNTL Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com XR16M2751 1.62V TO 3.63V HIGH PERFORMANCE DUART WITH 64-BYTE FIFO REV. 1.0.0 FIGURE 2. PIN OUT ASSIGNMENT D5 1 36 RESET D6 2 35 DTRB D7 3 34 DTRA RTSA RXB 4 33 OP2A RXA 5 32 XR16M2751 TXRDYB 6 31 RXRDYA 48-pin TQFP TXA 7 30 INTA in 16 (Intel) Mode TXB 8 29 INTB A0 OP2B 9 28 CSA 10 27 A1 CSB 11 26 A2 PWRSAVE 12 25 CLKSEL RESET D5 1 36 VCC D6 2 35 DTRB D7 3 34 DTRA RXB 4 33 RTSA RXA 5 32 OP2A XR16M2751 TXRDYB 6 31 RXRDYA 48-pin TQFP TXA 7 30 IRQ in 68 (Motorola) Mode TXB 8 29 NC OP2B 9 28 A0 10 27 A1 CS A2 A3 11 26 PWRSAVE 12 25 CLKSEL GND ORDERING INFORMATION PART NUMBER PACKAGE OPERATING TEMPERATURE RANGE DEVICE STATUS XR16M2751IM48 48-Lead TQFP -40C to +85C Active 2 XTAL1 48 D4 13 XTAL2 14 47 D3 IOW 15 46 D2 CDB 16 45 D1 GND 17 44 D0 RXRDYB 18 43 TXRDYA IOR 19 42 VCC DSRB 20 41 RIA RIB 40 21 CDA RTSB 39 22 DSRA CTSB 38 CTSA 23 16/68 37 HDCNTL 24 XTAL1 13 48 D4 XTAL2 47 14 D3 R/W 46 D2 15 CDB 45 D1 16 GND 17 44 D0 RXRDYB 18 43 TXRDYA NC 19 42 VCC DSRB 20 41 RIA RIB 21 40 CDA RTSB 22 39 DSRA CTSB 23 38 CTSA 16/68 24 37 HDCNTL