Hold Violations

Scan chain reordering in VLSI physical design explained: why synthesis scan order wastes wirelength, what the scan DEF (START/STOP, FLOATING, ORDERED, PARTITION, MAXBITS) allows, clock-domain, edge-order and lockup-latch rules, chain balancing, scan shift hold timing, verification and ATPG regeneration, with illustrative examples, a debugging flowchart and interview Q&As.

ECO (Engineering Change Order) in VLSI physical design explained: timing, DRV, noise, leakage and functional ECOs, pre-mask vs post-mask (metal-only) changes, spare cells, the sign-off STA to place-and-route ECO loop, what to re-verify after every ECO and how to debug an ECO that will not converge, with illustrative examples and interview Q&As.

Multicycle paths and false paths in STA explained for physical design and timing engineers: how set_multicycle_path moves setup and hold checks, why setup N needs hold N-1, -start vs -end across clocks, valid and dangerous false paths, clock groups, exception precedence and a debugging flow, with illustrative examples and interview Q&As.

Understand setup and hold time, calculate setup and hold slack with worked examples, and learn how to fix setup and hold violations in physical design.