Use these drills after completing all topics in PLL & DLL Clocking. Answer with boundary, mode, metric, artifact, owner, and regression.
[INT][AMS][PLL-DLL-CLOCKING]
Q: Why is lock bit insufficient for signoff?
A:
Lock indicates loop state, not jitter quality or mode-transition safety.
FOLLOW-UP TRAP: Skipping phase-noise and uncertainty correlation.[INT][AMS][PLL-DLL-CLOCKING]
Q: How do you budget PLL jitter across system path?
A:
Allocate source, loop, supply/package, and distribution contributions and verify endpoint margin.
FOLLOW-UP TRAP: Assigning all margin at STA side only.[INT][AMS][PLL-DLL-CLOCKING]
Q: Most common reset sequencing failure with PLL?
A:
Releasing dependent logic before lock is genuinely qualified across required settling windows.
FOLLOW-UP TRAP: Using fixed delay without mode awareness.BOUNDARY -> MECHANISM -> METRIC -> ARTIFACT -> FIX -> REGRESSIONCLOCKING FLOW
reference -> PLL/DLL -> distribution -> endpoint marginState boundary, mode, and evidence tag with every claim.
Always align analog, digital, and physical owners before signoff decisions.
Fixing averages while tails still fail.
Skipping package/supply evidence in jitter or SerDes issues.
Shipping with waivers that lack owner and expiration criteria.