LMH1983: Lock Determination function with the reference of a large amount of jitter

Shimizu-san,

Both are correct, but LOCK1_Threshold is the primary control (window size) while LockStepSize is more like a secondary control (window step size).  Here are more details:

The PLL1 lock detector compare the two PLL1 PFD inputs, PLL Ref clock edge (Hin / R_div) and PLL Feedback clock edge (VCXOin / N_div).  If 3 consecutive edges are within the lock detection window, it declares PLL is locked.  If 3 consecutive edges are outside the lock detection window, it declares PLL is unlocked.

• LOCK1_Threshold register (range: 0d to 63d, 64 steps, X ns/step) sets the lock detect window. The detection window is the clock phase difference in nanoseconds between PLL1 PFD inputs.
• LockStepSize register (range: 0d to 15d) adjusts the ns/step size (X).
  • X = (0.5 ns * 8) / LockStepSize
  • When LockStepSize = 8 (default), then X = 0.5 ns/step (nominal).

Examples:

• For Fast lock assert time (= relaxed frequency accuracy = Large window size), set LOCK1_Threshold = Maximum, LockStepSize = Minimum
• For Slow lock assert time (= strict frequency accuracy = Small window size), set LOCK1_Threshold = Minimum, LockStepSize = Maximum

Regards,
Alan

No problem, I will close this.

Thanks,
Alan