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

2.1.1 Check Status of APLL Reference

The APLL reference can be sourced externally from an XO input or internally from a cascaded source. For externally-sourced APLL references, the LMK device has an XO input detector that checks the validity of the XO input signal. The detector reports the validity of the signal through the "loss of frequency detection XO" bit. Refer to Table 2-13 for the bit definition. Table 2-2 shows the XO input frequency range and status registers for the LMK device families. For internally-sourced APLL references, use the APLL lock detector described in Is the APLL Locked? to check the validity of the cascaded source. The cascaded source is considered valid when the upstream APLL is locked.

Table 2-1 Loss of Frequency Detection XO - Status Bit Definition
BIT STATEMEANINGDESCRIPTION
0Desired resultThe LMK device detects an XO input that is within the data sheet frequency range (with some applied margin).
1Undesired resultThe LMK device detects an XO input that is outside the data sheet frequency range (with some applied margin).
Table 2-2 Loss of Frequency Detection XO - Status Register
DEVICE FAMILYXO FREQUENCY RANGE [MHz]TICS PRO FIELD NAMELOSS OF FREQUENCY DETECTION XO
REGISTER
LMK05318B, LMK0531810 to 100LOS_FDET_XOR13[4]
LMK5C10 to 100LOS_FDET_XOR33[0]
LMK5B, LMK5CA10 to 156.25LOS_FDET_XOR33[0]