XR19L210_07 Datasheet, PDF (42/43 Pages) Exar Corporation – SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER

XR19L210
SINGLE CHANNEL INTEGRATED UART AND RS-232 TRANSCEIVER
TABLE OF CONTENTS
REV. 1.0.1
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. XR19L210 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
FIGURE 9. RECEIVER OPERATION IN FIFO AND AUTO RTS FLOW CONTROL MODE ......................................................................... 11
2.12 AUTO RTS (HARDWARE) FLOW CONTROL ............................................................................................... 12
2.13 AUTO RTS HYSTERESIS............................................................................................................................... 12
2.14 AUTO CTS FLOW CONTROL ........................................................................................................................ 12
FIGURE 10. AUTO RTS AND CTS FLOW CONTROL OPERATION....................................................................................................... 13
2.15 AUTO XON/XOFF (SOFTWARE) FLOW CONTROL..................................................................................... 13
TABLE 4: AUTO XON/XOFF (SOFTWARE) FLOW CONTROL ............................................................................................................... 14
2.16 SPECIAL CHARACTER DETECT .................................................................................................................. 14
2.17 SLEEP MODES AND POWER-SAVE FEATURE WITH WAKE-UP INTERRUPT ........................................ 14
2.17.1 PARTIAL SLEEP MODE............................................................................................................................................. 14
2.17.1.1 UART IN SLEEP MODE, RS-232 TRANSCEIVER ACTIVE......................................................................................... 14
2.17.1.2 UART ACTIVE, CHARGE PUMP OF RS-232 TRANSCEIVER SHUT DOWN.................................................................. 15
2.17.2 FULL SLEEP MODE ................................................................................................................................................... 15
2.17.3 POWER-SAVE FEATURE .......................................................................................................................................... 16
2.18 INTERNAL LOOPBACK ................................................................................................................................. 17
FIGURE 11. INTERNAL LOOP BACK ................................................................................................................................................. 17
3.0 UART INTERNAL REGISTERS ............................................................................................................. 18
TABLE 5: UART INTERNAL REGISTERS .................................................................................................................................... 18
TABLE 6: INTERNAL REGISTERS DESCRIPTION. SHADED BITS ARE ENABLED WHEN EFR BIT-4=1 .......................................... 19
4.0 INTERNAL REGISTER DESCRIPTIONS............................................................................................... 20
4.1 RECEIVE HOLDING REGISTER (RHR) - READ- ONLY .................................................................................. 20
4.2 TRANSMIT HOLDING REGISTER (THR) - WRITE-ONLY ............................................................................... 20
4.3 BAUD RATE GENERATOR DIVISORS (DLL AND DLM) - READ/WRITE ...................................................... 20
4.4 INTERRUPT ENABLE REGISTER (IER) - READ/WRITE................................................................................. 20
4.4.1 IER VERSUS RECEIVE FIFO INTERRUPT MODE OPERATION ............................................................................... 20
4.4.2 IER VERSUS RECEIVE/TRANSMIT FIFO POLLED MODE OPERATION .................................................................. 21
I