Difficulty: Medium · Puzzle 4 of 6 · Topic: Sequence Puzzles
Property intent: from one start cycle, both sub-sequences must match: req ##1 gnt and req ##2 done. Timeline: C40 start=1 req=1, C41 gnt=1, C42 done=1. Determine the verdict.
property p_seq_and;
@(posedge clk) start |-> ((req ##1 gnt) and (req ##2 done));
endpropertyFor sequence and, both sequences share a start but may end at different cycles.
1) start triggers and launches both sequence branches at C40.
2) First branch req ##1 gnt matches (req at C40, gnt at C41).
3) Second branch req ##2 done matches (req at C40, done at C42).
4) Both branches match, so the and composition matches.Answer: PASS - both sequence branches succeed from the same start cycle, satisfying the sequence and operator.
A common mistake is assuming both branches must end on the same cycle (that is intersect, not and).
If done moved to C43, which part would fail first and why?