Timing Boundary Depth Scans

Capture Source Gate Three-Row Scan

The same input/prior state changes only when the timing source gate accepts. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Passing timing source lets the input replace prior state

Input stays 1 and prior stays 0. Setup slack 3 s and hold slack 1 s make the edge gate capture with output 1.

ssetup=3 s,shold=1 s⇒Q=1s_{\text{setup}}=3\ \text{s},\quad s_{\text{hold}}=1\ \text{s}\Rightarrow Q=1
Capture source-gate scanThe output follows the checked timing source gate.period 10 sedges 3edge 1 at 10 slast 20 sedge 1 at 10 sdata 5 snext 12 ssetup slack 3 shold slack 1 sacceptededge 1D 1prior 0Q 1captured

Setup-failed source keeps the prior state

Input stays 1 and prior stays 0. Setup slack -1 s and hold slack 1 s make the edge gate hold with output 0.

ssetup=−1 s,shold=1 s⇒Q=0s_{\text{setup}}=\mathord{-}1\ \text{s},\quad s_{\text{hold}}=1\ \text{s}\Rightarrow Q=0
Capture source-gate scanThe output follows the checked timing source gate.period 10 sedges 3edge 1 at 10 slast 20 sedge 1 at 10 sdata 9 snext 12 ssetup slack -1 shold slack 1 srejectededge 1D 1prior 0Q 0held

Hold-failed source also keeps the prior state

Input stays 1 and prior stays 0. Setup slack 3 s and hold slack negative 1/2 s make the edge gate hold with output 0.

ssetup=3 s,shold=−12 s⇒Q=0s_{\text{setup}}=3\ \text{s},\quad s_{\text{hold}}=\mathord{-}\tfrac{1}{2}\ \text{s}\Rightarrow Q=0
Capture source-gate scanThe output follows the checked timing source gate.period 10 sedges 3edge 1 at 10 slast 20 sedge 1 at 10 sdata 5 snext 21/2 ssetup slack 3 shold slack -1/2 srejectededge 1D 1prior 0Q 0held