SNAA421 November   2025 LMK05318B , LMK5B12204 , LMK5B33216 , LMK5B33414 , LMK5C33216A , LMK5C33414A

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Start Here: Using TICS Pro for Configuration and Readback
    1. 1.1 TICS Pro Status Page
    2. 1.2 TICS Pro Default Setting
  5. 2Debug Procedure: From Device Start-Up to Locked Output State
    1. 2.1 Is the APLL Reference Valid?
      1. 2.1.1 Check Status of APLL Reference
      2. 2.1.2 Debug APLL Reference
    2. 2.2 Is the APLL Locked?
      1. 2.2.1 Check Status of APLL Lock
      2. 2.2.2 Debug APLL Lock
    3. 2.3 Is the DPLL Reference Valid?
      1. 2.3.1 Check Status of DPLL Reference Validation
      2. 2.3.2 Debug DPLL Reference Validation
    4. 2.4 Is the DPLL Selecting a Reference?
      1. 2.4.1 Check Status of DPLL Reference Selection
      2. 2.4.2 Debug DPLL Reference Selection
    5. 2.5 Is the DPLL Frequency Locked?
      1. 2.5.1 Check Status of DPLL Frequency Lock
      2. 2.5.2 Debug DPLL Frequency Lock
    6. 2.6 Is the DPLL Phase Locked?
      1. 2.6.1 Check Status of DPLL Phase Lock
      2. 2.6.2 Debug DPLL Phase Lock
  6. 3Summary
  7. 4References

2.4.2 Debug DPLL Reference Selection

If the status is undesired, run through the following debug steps.

  1. Check the DPLL reference input mux setting.

    Confirm the mux option is configured properly. For example, for Auto-Revertive, Auto Non-Revertive, and Manual Fallback modes, make sure that at least one input is assigned a priority through the DPLLx_REFy_AUTO_PRTY register.

    Try forcing a selection by manually selecting one input using the Manual Holdover mode. Make sure to specify the selected input through either register or pin setting. If the DPLL remains in Holdover even though the reference is valid, contact TI by posting on the public TI E2E forum for further assistance.

  2. Create a new configuration.

    The DPLL input registers can be incorrect. Try generating a new configuration using TICS Pro.