Propagation delay
= Propagation delay
{title2=$t_{\mathrm{pd}}$}
The elapsed time between a change at a <logic gate>'s input and the corresponding settled change at its output, under specified loading and transition conditions. Dependent gate delays add along a path. The <combinational critical path> gives the longest such input-to-output path; reconvergent paths of unequal delay can produce a <logic hazard> even when the final <Boolean function> value does not change.