GOF beats Conformal ECO Case 1

Summary

The test case is extracted from a large hierarchical design. RTL changes affect 6 flops and 6 output ports. GOF auto ECO uses 24 cells 4.7 in area to fix the logic, while conformal ECO uses 76 cells 20.3 in area to fix the logic. To be fair in comparison, all cells in ECO use driver 'D0'.

Results Comparison

ECO Result	Total Cells	Non-Buffer	Invert	Buffer	Area
GOF	24	7	14	3	4.7
Conformal ECO	76	62	14	0	20.3

Files in ECO

gof_patch.v ----------------- GOF patch file, 24 cells
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 24 gates in total.

Figure 1 GOF ECO patch

While Conformal ECO generates a big patch with total 76 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