XR19L200_07 Datasheet, PDF (39/40 Pages) Exar Corporation – SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER

REV. 1.0.1
XR19L200
SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
TABLE OF CONTENTS
GENERAL DESCRIPTION................................................................................................ 1
APPLICATIONS .............................................................................................................................................. 1
FEATURES .................................................................................................................................................... 1
FIGURE 1. BLOCK DIAGRAM ............................................................................................................................................................. 1
FIGURE 2. PIN OUT OF THE DEVICE.................................................................................................................................................. 2
ORDERING INFORMATION ............................................................................................................................... 2
PIN DESCRIPTIONS ....................................................................................................... 3
1.0 PRODUCT DESCRIPTION ...................................................................................................................... 5
2.0 FUNCTIONAL DESCRIPTIONS .............................................................................................................. 6
2.1 CPU INTERFACE ................................................................................................................................................ 6
FIGURE 3. XR19L200 TYPICAL INTEL/MOTOROLA DATA BUS INTERCONNECTIONS ............................................................................. 6
2.2 5-VOLT TOLERANT INPUTS .............................................................................................................................. 7
2.3 DEVICE HARDWARE RESET............................................................................................................................. 7
2.4 DEVICE IDENTIFICATION AND REVISION ....................................................................................................... 7
2.5 INTERNAL REGISTERS...................................................................................................................................... 7
2.6 DMA MODE ......................................................................................................................................................... 7
2.7 INT (IRQ#) OUTPUT ............................................................................................................................................ 7
TABLE 1: INT (IRQ#) PIN OPERATION FOR TRANSMITTER ................................................................................................................. 7
TABLE 2: INT (IRQ#) PIN OPERATION FOR RECEIVER ...................................................................................................................... 8
2.8 CRYSTAL OR EXTERNAL CLOCK INPUT ........................................................................................................ 8
FIGURE 4. TYPICAL CRYSTAL CONNECTIONS ..................................................................................................................................... 8
2.9 PROGRAMMABLE BAUD RATE GENERATOR............................................................................................... 8
FIGURE 5. BAUD RATE GENERATOR AND PRESCALER ....................................................................................................................... 9
TABLE 3: TYPICAL DATA RATES WITH A 14.7456 MHZ CRYSTAL OR EXTERNAL CLOCK ........................................................................ 9
2.10 TRANSMITTER.................................................................................................................................................. 9
2.10.1 TRANSMIT HOLDING REGISTER (THR) - WRITE ONLY........................................................................................... 9
2.10.2 TRANSMITTER OPERATION IN NON-FIFO MODE .................................................................................................. 10
FIGURE 6. TRANSMITTER OPERATION IN NON-FIFO MODE .............................................................................................................. 10
2.10.3 TRANSMITTER OPERATION IN FIFO MODE ........................................................................................................... 10
FIGURE 7. TRANSMITTER OPERATION IN FIFO AND FLOW CONTROL MODE ..................................................................................... 10
2.11 RECEIVER ....................................................................................................................................................... 10
2.11.1 RECEIVE HOLDING REGISTER (RHR) - READ-ONLY ............................................................................................ 11
FIGURE 8. RECEIVER OPERATION IN NON-FIFO MODE.................................................................................................................... 11
2.12 AUTO XON/XOFF (SOFTWARE) FLOW CONTROL..................................................................................... 11
TABLE 4: AUTO XON/XOFF (SOFTWARE) FLOW CONTROL ............................................................................................................... 12
2.13 SPECIAL CHARACTER DETECT.................................................................................................................. 12
2.14 SLEEP MODES WITH WAKE-UP INTERRUPT............................................................................................. 12
2.14.1 PARTIAL SLEEP MODE............................................................................................................................................. 12
2.14.1.1 UART IN SLEEP MODE, RS-232 TRANSCEIVER ACTIVE......................................................................................... 12
2.14.1.2 UART ACTIVE, CHARGE PUMP OF RS-232 TRANSCEIVER SHUT DOWN.................................................................. 13
2.14.2 FULL SLEEP MODE ................................................................................................................................................... 13
2.15 INTERNAL LOOPBACK................................................................................................................................. 14
FIGURE 9. INTERNAL LOOP BACK ................................................................................................................................................... 14
3.0 UART INTERNAL REGISTERS............................................................................................................. 15
TABLE 5: UART INTERNAL REGISTERS .................................................................................................................................... 15
TABLE 6: INTERNAL REGISTERS DESCRIPTION. SHADED BITS ARE ENABLED WHEN EFR BIT-4=1 .......................................... 16
4.0 INTERNAL REGISTER DESCRIPTIONS .............................................................................................. 17
4.1 RECEIVE HOLDING REGISTER (RHR) - READ- ONLY .................................................................................. 17
4.2 TRANSMIT HOLDING REGISTER (THR) - WRITE-ONLY ............................................................................... 17
4.3 BAUD RATE GENERATOR DIVISORS (DLL AND DLM) - READ/WRITE ...................................................... 17
4.4 INTERRUPT ENABLE REGISTER (IER) - READ/WRITE ................................................................................ 17
4.4.1 IER VERSUS RECEIVE FIFO INTERRUPT MODE OPERATION ............................................................................... 17
4.4.2 IER VERSUS RECEIVE/TRANSMIT FIFO POLLED MODE OPERATION.................................................................. 18
4.5 INTERRUPT STATUS REGISTER (ISR) - READ-ONLY .................................................................................. 19
4.5.1 INTERRUPT GENERATION: ........................................................................................................................................ 19
4.5.2 INTERRUPT CLEARING: ............................................................................................................................................. 19
TABLE 7: INTERRUPT SOURCE AND PRIORITY LEVEL ....................................................................................................................... 19
4.6 FIFO CONTROL REGISTER (FCR) - WRITE-ONLY ........................................................................................ 20
TABLE 8: TRANSMIT AND RECEIVE FIFO TRIGGER LEVEL SELECTION .............................................................................................. 21
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