SLLS177I March   1994  – March 2021 TL16C550C

PRODUCTION DATA  

  1. 1 Features
  2. 2 Description
  3. 3 Revision History
  4. 4 Pin Configuration and Functions
  5. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  Recommended Operating Conditions (Low Voltage - 3.3 nominal)
    3. 5.3  Recommended Operating Conditions (Standard Voltage - 5 V nominal)
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics (Low Voltage - 3.3 V nominal)
    6. 5.6  Electrical Characteristics (Standard Voltage - 5 V nominal)
    7. 5.7  System Timing Requirements
    8. 5.8  System Switching Characteristics
    9. 5.9  Baud Generator Switching Characteristics
    10. 5.10 Receiver Switching Characteristics
    11. 5.11 Transmitter Switching Characteristics
    12. 5.12 Modem Control Switching Characteristics
  6. 6 Parameter Measurement Information
  7. 7 Detailed Description
    1. 7.1 Autoflow Control (see Figure 1-1)
    2. 7.2 Auto-RTS (see Figure 1-1)
    3. 7.3 Auto-CTS (see Figure 1-1)
    4. 7.4 Enabling Autoflow Control and Auto-CTS
    5. 7.5 Auto-CTS and Auto-RTS Functional Timing
    6. 7.6 Functional Block Diagram
    7. 7.7 Principles of Operation
      1. 7.7.1  Accessible Registers
      2. 7.7.2  FIFO Control Register (FCR)
      3. 7.7.3  FIFO Interrupt Mode Operation
      4. 7.7.4  FIFO Polled Mode Operation
      5. 7.7.5  Interrupt Enable Register (IER)
      6. 7.7.6  Interrupt Identification Register (IIR)
      7. 7.7.7  Line Control Register (LCR)
      8. 7.7.8  Line Status Register (LSR)
      9. 7.7.9  Modem Control Register (MCR)
      10. 7.7.10 Modem Status Register (MSR)
      11. 7.7.11 Programming Baud Generator
      12. 7.7.12 Receiver Buffet Register (RBR)
      13. 7.7.13 Scratch Register
      14. 7.7.14 Transmitter Holding Register (THR)
  8. 8 Application Information
  9. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.7.4 FIFO Polled Mode Operation

With FCR0 = 1 (transmitter and receiver FIFOs enabled), clearing IER0, IER1, IER2, IER3, or all four to 0 puts the ACE in the FIFO polled mode of operation. Since the receiver and transmitter are controlled separately, either one or both can be in the polled mode of operation.

In this mode, the user program checks receiver and transmitter status using the LSR. As stated previously:

  • LSR0 is set as long as there is one byte in the receiver FIFO.
  • LSR1 − LSR 4 specify which error(s) have occurred. Character error status is handled the same way as when in the interrupt mode; the IIR is not affected since IER2 = 0.
  • LSR5 indicates when the THR is empty.
  • LSR6 indicates that both the THR and TSR are empty.
  • LSR7 indicates whether there are any errors in the receiver FIFO.

There is no trigger level reached or time-out condition indicated in the FIFO polled mode. However, the receiver and transmitter FIFOs are still fully capable of holding characters.