In certain situations, ECOs can be very complex, and relying solely on automatic mode may not yield satisfactory results. Optimal ECO patching often requires a combination of both Automatic ECO and Manual ECO.
For instance, consider an ECO case in which a new bus port (IN_B) is required to control half of the logic (LOGIC B) that was originally controlled by bus port A (IN_A). LOGIC A and LOGIC B may have some overlap, and LOGIC C also requires fixing, including data path changes that must be done using Automatic ECO.
If only Automatic ECO is applied, Fix 1 (IN_A/IN_B/LOGIC-A/LOGIC-B) would require approximately 200 gates. However, by using GOF APIs to analyze the logic paths from port IN_A to STATE_A_reg and STATE_B_reg, we can identify that LOGIC A and LOGIC B have very few gated shared. Thus, duplicating these shared gates would allow for a clean cut of LOGIC A and LOGIC B, enabling them to be driven separately by IN_A and IN_B. Click here for this mixed mode ECO use case.
Figure 1: Mixed Automatic and Manual ECO