SLLS890C August   2008  – April 2024 TL28L92

PRODUCTION DATA  

  1.   1
  2. 1Features
  3. 2Description
  4. 3Pin Configurations and Functions
  5. 4Electrical Specifications
    1. 4.1 Absolute Maximum Ratings
    2. 4.2 Static Characteristics for 5V Operation
    3. 4.3 Static Characteristics for 3.3V Operation
    4. 4.4 Dynamic Characteristics for 5V Operation
    5. 4.5 Dynamic Characteristics for 3.3V Operation
    6. 4.6 Typical Performance
    7. 4.7 Timing Diagrams
    8. 4.8 Test Information
  6. 5Detailed Description
    1. 5.1 Overview
    2. 5.2 Functional Block Diagram
    3. 5.3 Feature Description
      1. 5.3.1 Data Bus Buffer
      2. 5.3.2 Operation Control
      3. 5.3.3 Interrupt Control
      4. 5.3.4 FIFO Configuration
      5. 5.3.5 68xxx Mode
      6. 5.3.6 Timing Circuits
        1. 5.3.6.1  Crystal Clock
        2. 5.3.6.2  Baud Rate Generator
        3. 5.3.6.3  Counter/Timer
        4. 5.3.6.4  Timer Mode
        5. 5.3.6.5  Counter Mode
        6. 5.3.6.6  Time-Out Mode
        7. 5.3.6.7  Time-Out Mode Caution
        8. 5.3.6.8  Communications Channels A and B
        9. 5.3.6.9  Input Port
        10. 5.3.6.10 Output Port
      7. 5.3.7 Operation
        1. 5.3.7.1 Transmitter
        2. 5.3.7.2 Receiver
        3. 5.3.7.3 Transmitter Reset and Disable
        4. 5.3.7.4 Receiver FIFO
        5. 5.3.7.5 Receiver Status Bits
        6. 5.3.7.6 Receiver Reset and Disable
        7. 5.3.7.7 Watchdog
        8. 5.3.7.8 Receiver Time-Out Mode
        9. 5.3.7.9 Time-Out Mode Caution
  7. 6Programming
    1. 6.1 Register Overview
    2. 6.2 Condensed Register Bit Formats
    3. 6.3 Register Descriptions
      1. 6.3.1  Mode Registers
        1. 6.3.1.1 Mode Register 0 Channel A (MR0A)
        2. 6.3.1.2 Mode Register 1 Channel A (MR1A)
        3. 6.3.1.3 Mode Register 2 Channel A (MR2A)
        4. 6.3.1.4 Mode Register 0 Channel B (MR0B)
        5. 6.3.1.5 Mode Register 1 Channel B (MR1B)
        6. 6.3.1.6 Mode Register 2 Channel B (MR2B)
      2. 6.3.2  Clock Select Registers
        1. 6.3.2.1 Clock Select Register Channel A (CSRA)
        2. 6.3.2.2 Clock Select Register Channel B (CSRB)
      3. 6.3.3  Command Registers
        1. 6.3.3.1 Command Register Channel A (CRA)
        2. 6.3.3.2 Command Register Channel B (CRB)
      4. 6.3.4  Status Registers
        1. 6.3.4.1 Status Register Channel A (SRA)
        2. 6.3.4.2 Status Register Channel B (SRB)
      5. 6.3.5  Output Configuration Control Register (OPCR)
      6. 6.3.6  Set Output Port Bits Register (SOPR)
      7. 6.3.7  Reset Output Port Bits Register (ROPR)
      8. 6.3.8  Output Port Register (OPR)
      9. 6.3.9  Auxiliary Control Register (ACR)
      10. 6.3.10 Input Port Change Register (IPCR)
      11. 6.3.11 Interrupt Status Register (ISR)
      12. 6.3.12 Interrupt Mask Register (IMR)
      13. 6.3.13 Interrupt Vector Register (IVR; 68xxx Mode) or General Purpose Register (GP; 80xxx Mode)
      14. 6.3.14 Counter and Timer Registers
    4. 6.4 Output Port Notes
    5. 6.5 CTS, RTS, CTS Enable Tx Signals
  8. 7Device and Documentation Support
    1. 7.1 Receiving Notification of Documentation Updates
    2. 7.2 Support Resources
    3. 7.3 Trademarks
    4. 7.4 Electrostatic Discharge Caution
    5. 7.5 Glossary
  9. 8Revision History
  10. 9Mechanical, Packaging, and Orderable Information

Package Options

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

5.3.6.3 Counter/Timer

The Counter/timer is a 16-bit programmable divider that operates in one of three modes: counter, timer and time-out. In the timer mode it generates a square wave. In the counter mode, it generates a time delay. In the time-out mode, it monitors the time between received characters. The C/T uses the numbers loaded into the Counter/Timer Lower Register (CTLR) and the Counter/Timer Upper Register (CTUR) as its divisor.

The counter/timer clock source and mode of operation (counter or timer) is selected by the Auxiliary Control Register bits 6 to 4 (ACR[6:4]). The output of the counter/timer may be used for a baud rate and/or may be output to the OP pins for some external function that may be totally unrelated to data transmission. The counter/timer also sets the counter/timer ready bit in the Interrupt Status Register (ISR) when its output transitions from logic 1 to logic 0. A register read address (see Table 6-1) is reserved to issue a start counter/timer command and a second register read address is reserved to issue a stop command. The value of D(7:0) is ignored. The START command always loads the contents of CTUR, CTLR to the counting registers. The STOP command always resets the ISR[3] bit in the interrupt status register.