ECO基本概念：pre-mask eco gen patch flow

使用conformal LEC 进行pre-mask eco 时，如何产生patch，参考以下步骤：

官方推荐 Flattened ECO Flow（FEF）

Conformal支持Flattened ECO Flow和Hierarchical ECO Flow。Flattened下，工具会将 ECO 分析重点放在从平面比较中确定的非等效关键点上，env容易设置，所有 ECO 补丁都可以用一个命令创建。
 

总结的话是

env variable set;

read library and design;

set constraint;

flatten or hierarchical compare; 

begin eco, generate patch, write G3 design

1. Read the Liberty libraries into the library space for both Golden and Revised.

2. Read the G1 netlist into the golden design space and the G2 netlist into the revised design space.

3. After applying any design constraints (such as disabling scan in the G1 netlist), you can either do a flat or hierarchical comparison (see Flattened Comparison FlowFlattened Comparison Flow and Hierarchical Comparison FlowHierarchical Comparison Flow sections to determine which is the best for your design).

4. Run the ANALYZE ECO command on the nonequivalent points. Conformal ECO Designer will look at each nonequivalent cone of logic and try to create the smallest patch possible.

5. Once the patch is created, you will need to go back to SETUP mode and apply the patch back to the G1 netlist. This is done with the APPLY PATCH command.

6. At this point the patch has been applied, but it still contains primitive cells. Use the OPTIMIZE PATCH command to map these cells to the technology library cells. This command maps the primitives and does an in-place optimization of each patch. Once completed, the mapped patches are passed back to Conformal ECO Designer. At this point, the new G3 design can be written out along with a change script that can be passed to EDI for incremental placement and routing.