Transparent Latch Captures Only Inside Its Window - Electronic Circuits XII: Clocks, Latches, and Timing Closure Step by Step

The latch window is half-open and checked by exact arrival time. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

A transparent latch captures inside its open window

The latch is open from 4 seconds to just before 7 seconds, and the input arrives at 5 seconds.

4\le 5<7

Arrivals before the right endpoint are captured

The half-open window accepts interior arrivals and blocks the endpoint row.

\begin{array}{c|c|c}t_D&Q&\text{gate}\\5\ \text{s}&1&\text{capture}\\6\ \text{s}&1&\text{capture}\\7\ \text{s}&0&\text{block}\\\end{array}

The right endpoint is blocked by convention

An arrival exactly at 7 seconds is outside the half-open window, so the output stays 0.

7\not<7\quad Q=0