The log is the run: commands, revisions, warnings and QoR lines in one file. A number without a log is an anecdote.
Log section | What it records |
|---|---|
Header | Command lines plus tool, library, constraint and script revisions. |
Stage echoes | One line per stage with its input and output design names. |
Warnings | Warning count by category; new warnings fail the nightly run. |
QoR lines | Area, worst slack and power with units, one line each. |
Each run reduces to three numbers with stated units. All three are EXAMPLE measurements from a recorded run, never process data.
Metric | Unit here | Read from |
|---|---|---|
Area | Area units of | Mapped cell areas summed over the netlist. |
Worst slack | Picoseconds, EXAMPLE clock | Required minus arrival on the worst path. |
Power | EXAMPLE microwatts at stated activity | Switching plus internal plus leakage estimates. |
Extraction copies the three numbers into one record keyed by run parameters. The calc block works one EXAMPLE record by hand.
EXAMPLE record: 8-bit adder, course.lib area units, EXAMPLE clock
required time 1000 ps, worst arrival 880 ps
worst slack = required - arrival = 1000 - 880 = 120 ps
area against the 4-bit record: 104 / 52 = 2, exactly double
power against the 4-bit record: 63 vs 62, up 1 unit = 1 / 62 = 1.61%120 ps. Slack is required minus arrival: 1000 minus 880 is 120.
Only that this EXAMPLE scales linearly here. It promises nothing about other widths, structures or libraries.