Every CDC bug starts with a crossing nobody wrote down. This topic fixes the vocabulary first: what counts as a crossing, how the clock relationship shapes the answer, what goes wrong, and why simulation alone cannot clear a design.
Lesson | After it you can... |
|---|---|
Say exactly which flop-to-flop paths are crossings and which domain each flop belongs to. | |
Classify a clock pair and say why the relationship decides the synchronisation method. | |
Name the five CDC failure modes and match a symptom to its likely cause. | |
Explain what simulation can and cannot prove, and why structural and formal methods exist. |
Read them in order: the definition feeds the relationships, which feed the failures, which motivate the methodology.
Whether clk_a and clk_b are the same clock net. Different nets mean a crossing, whatever the frequencies. The first lesson makes this precise.