SLLSF10 December   2019 TL16C750E

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Block Diagram
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. Table 1. Absolute Maximum Ratings
    2. 7.1      ESD Ratings
    3. Table 2. Recommended Operating Conditions
    4. Table 3. Thermal Information
    5. Table 4. Electrical Characteristics
    6. Table 5. Timing Requirements
    7. 7.2      Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagrams
    3. 9.3 Feature Description
      1. 9.3.1  UART Modes
      2. 9.3.2  Trigger Levels
      3. 9.3.3  Hardware Flow Control
      4. 9.3.4  Auto-RTS
      5. 9.3.5  Auto-CTS
      6. 9.3.6  Software Flow Control
      7. 9.3.7  Software Flow Control Example
      8. 9.3.8  Reset
      9. 9.3.9  Interrupts
      10. 9.3.10 Interrupt Mode Operation
      11. 9.3.11 Polled Mode Operation
      12. 9.3.12 Break and Timeout Conditions
      13. 9.3.13 Programmable Baud Rate Generator with Fractional Divisor
      14. 9.3.14 Fractional Divisor
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device Interface Mode
        1. 9.4.1.1 IOR Used (MODE = VCC)
        2. 9.4.1.2 IOR Unused (MODE = GND)
      2. 9.4.2 DMA Signaling
        1. 9.4.2.1 Single DMA Transfers (DMA Mode 0 or FIFO Disable)
        2. 9.4.2.2 Block DMA Transfers (DMA Mode 1)
      3. 9.4.3 Sleep Mode
    5. 9.5 Register Maps
      1. 9.5.1  Registers Operations
      2. 9.5.2  Receiver Holding Register (RHR)
      3. 9.5.3  Transmit Holding Register (THR)
      4. 9.5.4  FIFO Control Register (FCR)
      5. 9.5.5  Line Control Register (LCR)
      6. 9.5.6  Line Status Register (LSR)
      7. 9.5.7  Modem Control Register (MCR)
      8. 9.5.8  Modem Status Register (MSR)
      9. 9.5.9  Interrupt Enable Register (IER)
      10. 9.5.10 Interrupt Identification Register (IIR)
      11. 9.5.11 Enhanced Feature Register (EFR)
      12. 9.5.12 Divisor Latches (DLL, DLH, DLF)
      13. 9.5.13 Transmission Control Register (TCR)
      14. 9.5.14 Trigger Level Register (TLR)
      15. 9.5.15 FIFO Ready Register
      16. 9.5.16 Alternate Function Register (AFR)
      17. 9.5.17 RS-485 Mode
      18. 9.5.18 IrDA Overview
      19. 9.5.19 IrDA Encoder Function
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Set the desired baud rate
        2. 10.2.2.2 Reset the fifos
        3. 10.2.2.3 Sending data on the bus
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Examples
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

10.2.2.1 Set the desired baud rate

As per Table 29, the desired baud rate is 9600 with an input clock of 24 MHz. The math required to calculate the register values is outlined in Programmable Baud Rate Generator with Fractional Divisor and Fractional Divisor. Since the device by default uses a 16x over sample setting, the math is 24E9 / (16 * 9600) = 156.25. This shows that the fractional baud rate feature is required to achieve 9600 baud. Since the fractional baud rate gives x/64 resolution, 0.25 * 64 = 16. The below values are the divisor values to be used in the registers.

Table 30. 9600 baud divisor values

Register Description Value
DLH MSB of the divisor 0x00
DLL LSB of the divisor 0x9C
DLF Fractional (1/64) divisor 0x10

Since these registers have access considerations in order to write to them (see Table 13), a few extra writes are required to enable the writes to the desired registers.

Table 31. Register writes to configure baud rate

Step Description Register & Access Type Value
1 Enable access to EFR (enhanced function) register LCR (0b011) [W] 0xBF
2 Enable the enhanced functionality (fractional baud rate) EFR (0b010) [W] 0x10
3 Enable extra feature registers and 8 bits/no parity/1 stop bit LCR (0b011) [W] 0x93
4 Write the MSB of the divisor DLH (0b001) [W] 0x00
5 Write to the LSB of the divisor DLL (0b000) [W] 0x9C
6 Write to the fractional divisor DLF (0b111) [W] 0x10
7 Change LCR back to normal mode LCR (0b011) [W] 0x13