XR16L784 Datasheet, PDF (50/52 Pages) Exar Corporation – HIGH PERFORMANCE 2.97V TO 5.5V QUAD UART

XR16L784
HIGH PERFORMANCE 5V AND 3.3V QUAD UART
REV. P1.2.0
TABLE OF CONTENTS
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PRELIMINARY
GENERAL DESCRIPTION ............................................................................................... 1
APPLICATIONS ........................................................................................................................................... 1
FEATURES ................................................................................................................................................. 1
Figure 1. Block Diagram ....................................................................................................................... 1
Figure 2. Pin Out Assignment .............................................................................................................. 2
ORDERING INFORMATION ............................................................................................................................ 2
PIN DESCRIPTIONS ....................................................................................................... 3
1.0 DESCRIPTION ........................................................................................................................................ 6
2.0 Functional Descriptions ........................................................................................................................ 6
2.1 DEVICE RESET .............................................................................................................................................................. 6
2.1.1 Hardware Reset ....................................................................................................................... 6
2.1.2 Software Reset ......................................................................................................................... 6
2.2 UART CHANNEL SELECTION ......................................................................................................................................... 6
2.3 SIMULTANEOUS WRITE TO ALL CHANNELS ..................................................................................................................... 6
TABLE 1: UART CHANNEL SELECTION ...................................................................................................... 6
2.4 INT# OUPUT ................................................................................................................................................................ 7
2.5 CRYSTAL OSCILLATOR / BUFFER .......................................................................................................................... 7
TABLE 2: INT# PIN OPERATION FOR TRANSMITTER ................................................................................... 7
TABLE 3: INT# PIN OPERATION FOR RECEIVER ......................................................................................... 7
Figure 3. Typical oscillator connections ............................................................................................. 7
2.6 PROGRAMMABLE BAUD RATE GENERATOR .................................................................................................................... 8
Figure 4. External Clock Connection for Extended Data Rate .......................................................... 8
Figure 5. Baud Rate Generator ............................................................................................................. 8
2.7 TRANSMITTER ............................................................................................................................................................... 9
2.7.1 Transmit Holding Register (THR) - Write Only ......................................................................... 9
2.7.2 Transmitter Operation in non-FIFO Mode ................................................................................ 9
TABLE 4: TYPICAL DATA RATES WITH A 14.7456 MHZ CRYSTAL OR EXTERNAL CLOCK AT 16X SAMPLING ... 9
2.7.3 Transmitter Operation in FIFO Mode ..................................................................................... 10
2.8 RECEIVER ................................................................................................................................................................... 10
Figure 6. Transmitter Operation in non-FIFO Mode ......................................................................... 10
Figure 7. Transmitter Operation in FIFO and Flow Control Mode ................................................... 10
2.8.1 Receive Holding Register (RHR) - Read-Only ....................................................................... 11
Figure 8. Receiver Operation in non-FIFO Mode .............................................................................. 11
Figure 9. Receiver Operation in FIFO and Auto RTS Flow Control Mode ...................................... 11
2.9 THR AND RHR REGISTER LOCATIONS ........................................................................................................................ 12
2.10 AUTOMATIC RTS/DTR HARDWARE FLOW CONTROL OPERATION ................................................................................ 12
TABLE 5: TRANSMIT AND RECEIVE DATA REGISTER, 16C550 COMPATIBLE .............................................. 12
2.10.1 Auto CTS/DSR Flow Control ................................................................................................ 13
Figure 10. Auto RTS/DTR and CTS/DSR Flow Control Operation ................................................... 13
2.11 AUTO XON/XOFF (SOFTWARE) FLOW CONTROL ......................................................................................................... 14
2.12 SPECIAL CHARACTER DETECT .................................................................................................................................. 14
TABLE 6: AUTO XON/XOFF (SOFTWARE) FLOW CONTROL ........................................................................ 14
2.13 AUTO RS485 HALF-DUPLEX CONTROL ..................................................................................................................... 15
2.14 INFRARED MODE ....................................................................................................................................................... 15
Figure 11. Infrared Transmit Data Encoding and Receive Data Decoding ..................................... 16
2.15 SLEEP MODE WITH AUTO WAKE-UP ......................................................................................................................... 17
2.16 INTERNAL LOOPBACK ................................................................................................................................................ 18
Figure 12. Internal Loop Back ............................................................................................................ 18
3.0 XR16L784 REGISTERS ........................................................................................................................ 19
3.1 DEVICE CONFIGURATION REGISTER SET ........................................................................................ 19
Figure 13. The XR16L784 Registers Mapping ................................................................................... 19
TABLE 7: XR16L784 REGISTER SETS ..................................................................................................... 19
TABLE 8: DEVICE CONFIGURATION REGISTERS ........................................................................................ 20
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