Capture and Timing Closure Audit

Failed Window Keeps the Prior State

A rejected timing source keeps the previous stored value. 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 failed setup-hold source blocks capture

The setup slack is -1 second, so this edge keeps the prior state.

ssetup=−1 s,captured=0s_{\text{setup}}=-1\ \text{s},\quad \text{captured}=0
Rejected capture sourceThe capture bit follows the failed setup check.period 8 sedges 4edge 1 at 8 slast 24 sedge 1 at 8 sdata 7 snext 10 ssetup slack -1 shold slack 1 srejectededge 1D 1prior 0Q 0held

Failed timing rows keep the prior state

Setup-fail and hold-fail source rows both block the edge capture.

ssetupsholdQnewgate−1 s1 s0hold−2 s1 s0hold1 s−12 s0hold\begin{array}{c|c|c|c}s_{\text{setup}}&s_{\text{hold}}&Q_{\text{new}}&\text{gate}\\\mathord{-}1\ \text{s}&1\ \text{s}&0&\text{hold}\\\mathord{-}2\ \text{s}&1\ \text{s}&0&\text{hold}\\1\ \text{s}&\mathord{-}\tfrac{1}{2}\ \text{s}&0&\text{hold}\\\end{array}

The output remains the previous value

Even though the input is 1, the output remains 0.

D=1,Qnew=0D=1,\quad Q_{\text{new}}=0
Held stateThe output label is tied to the rejected source.period 8 sedges 4edge 1 at 8 slast 24 sedge 1 at 8 sdata 7 snext 10 ssetup slack -1 shold slack 1 srejectededge 1D 1prior 0Q 0held