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'.
ECO Result | Total Cells | Non-Buffer | Invert | Buffer | Area |
GOF | 4 | 1 | 3 | 0 | 2.1 |
Conformal ECO | 28 | 24 | 4 | 0 | 29.2 |
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
The files can be downloaded to reproduce the result
gof -lib mp16.lib imp.v -ref ref.v -run eco.gpl