XR16L784CV-F Datasheet, PDF (50/51 Pages) Exar Corporation – HIGH PERFORMANCE 2.97V TO 5.5V QUAD UART

XR16L784
HIGH PERFORMANCE 2.97V TO 5.5V QUAD UART
TABLE OF CONTENTS
REV. 1.2.3
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
TABLE 1: UART CHANNEL SELECTION ................................................................................................................................................ 6
2.3 SIMULTANEOUS WRITE TO ALL CHANNELS .................................................................................................. 6
2.4 INT# OUPUT ......................................................................................................................................................... 7
TABLE 2: INT# PIN OPERATION FOR TRANSMITTER ............................................................................................................................. 7
TABLE 3: INT# PIN OPERATION FOR RECEIVER .................................................................................................................................. 7
2.5 CRYSTAL OSCILLATOR / BUFFER ................................................................................................................... 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
TABLE 4: TYPICAL DATA RATES WITH A 14.7456 MHZ CRYSTAL OR EXTERNAL CLOCK AT 16X SAMPLING .............................................. 9
2.7 TRANSMITTER .................................................................................................................................................... 9
2.7.1 TRANSMIT HOLDING REGISTER (THR) - WRITE ONLY ............................................................................................ 9
2.7.2 TRANSMITTER OPERATION IN NON-FIFO MODE ..................................................................................................... 9
Figure 6. Transmitter Operation in non-FIFO Mode ....................................................................................................................... 10
2.7.3 TRANSMITTER OPERATION IN FIFO MODE ............................................................................................................ 10
Figure 7. Transmitter Operation in FIFO and Flow Control Mode .................................................................................................. 10
2.8 RECEIVER ......................................................................................................................................................... 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
TABLE 5: TRANSMIT AND RECEIVE DATA REGISTER, 16C550 COMPATIBLE ......................................................................................... 12
2.10 AUTOMATIC RTS/DTR HARDWARE FLOW CONTROL OPERATION ......................................................... 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
TABLE 6: AUTO XON/XOFF (SOFTWARE) FLOW CONTROL .................................................................................................................. 14
2.12 SPECIAL CHARACTER DETECT .................................................................................................................. 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 WAKE-UP INDICATOR ................................................................................................ 17
2.16 INTERNAL LOOPBACK .................................................................................................................................. 18
Figure 12. Internal Loop Back ........................................................................................................................................................ 18
3.0 XR16L784 REGISTERS ........................................................................................................................ 19
Figure 13. The XR16L784 Registers Mapping ............................................................................................................................... 19
3.1 DEVICE CONFIGURATION REGISTER SET ................................................................................................... 19
TABLE 7: XR16L784 REGISTER SETS .............................................................................................................................................. 19
TABLE 8: DEVICE CONFIGURATION REGISTERS .................................................................................................................................. 20
3.1.1 THE GLOBAL INTERRUPT SOURCE REGISTERS ................................................................................................... 21
Figure 14. The Global Interrupt Registers, INT0, INT1, INT2 and INT3 ......................................................................................... 21
TABLE 9: UART CHANNEL [3:0] INTERRUPT SOURCE ENCODING AND CLEARING ................................................................................ 22
3.1.2 GENERAL PURPOSE 16-BIT TIMER/COUNTER. [TIMERMSB, TIMELSB, TIMER, TIMECNTL] (DEFAULT 0XXX-XX-
00-00) ..................................................................................................................................................................................... 22
Figure 15. Timer/Counter circuit. .................................................................................................................................................... 22
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