GOF beats Conformal ECO Case 2

Summary

The test case is extracted from a large hierarchical design. RTL changes affect 4 flops and 3 output ports. GOF auto ECO uses 4 gates and 2.1 in area to fix the logic, while conformal ECO uses 28 gates and 29.2 in area to fix the logic. All gates in ECO use driver 'X4'.

Results Comparison

ECO Result	Total Cells	Non-Buffer	Invert	Buffer	Area
GOF	4	1	3	0	2.1
Conformal ECO	28	24	4	0	29.2

Files in ECO

• gof_patch.v ----------------- GOF patch file, 4 gates
• cfm_eco_patch_1.v ------- Conformal ECO patch file, 28 gates
• imp.v -------------------------- Implementation netlist
• ref.v --------------------------- Reference netlist
• mp16.lib ---------------------- Liberty file. Warning! Since timing information is removed, the file can not be used in Synthesis
• eco.gpl -------------------------- GOF ECO script

Comparison on Schematic

 GOF generates a patch having three inputs, two outputs and 5 gates in total.

Figure 1 GOF ECO patch

While Conformal ECO generates a big patch with tens inputs and outputs, total 28 gates.

Figure 2 Conformal ECO patch

GOF command line

The files can be downloaded to reproduce the result

gof -lib mp16.lib imp.v -ref ref.v -run eco.gpl