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This article mainly introduces "how to diagnose unmapped key points". In daily operation, I believe many people have doubts about how to diagnose unmapped key points. The editor consulted all kinds of data and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "how to diagnose unmapped key points". Next, please follow the editor to study!

After map, if there is a unmappped key points, you can use the command "report_unmapped_points" plus a different option to report each unmapped key points, and there are two sub-options for option-unreachable that can be further subdivided according to the cause of the unreachable.

For example:

You can use the command "report_gate-unreach" to further confirm which fanout gate caused the unreachable, and the LEC starts from unreachable key point and trace all the way to the point where the unreachable is created.

For example:

For Extra key point, first confirm whether it is a real Extra and whether a match can be found by setting it to it. If you use the command "add_pin_constraints" to make a constant constraint on the primary input of Extra, these constrained points will no longer be classified as "Extra key point". Whether such a constraint can be added needs to be confirmed by designer. If some Extra primary output is useless in function mode, you can set it with the command "add_ignored_outputs", such as scan_out.

For Not-mapped key points, first confirm whether it is caused by renaming, if so, confirm whether it can be solved by the command "add_renaming_rule" plus renaming rule, and then confirm whether it is caused by incomplete or improper modeling. If so, you can use the command "set_flatten_model" to set the corresponding modeling option. Usually set "set_analyze_option-auto" before map to let LEC automatically enable the commonly used modeling option in the process of map. You can also use the command "analyze_setup" to analyze.

You can use the command "remodel-notmapped" to restrict which modeling option is used.

It is usually recommended to use the command "set_flatten_model" to do global settings, if there is still not-mapped point after map, then try to use the command "remodel".

You can use the command "analyze_redundancy" to analyze whether a Seqential cell is a redundant cell.

You can use the command "analyze_gate" to analyze whether not-mapped key points is a constant register, it will report whether the analyzed point is constant, and it will also trace whether the fanin of the key points has a constant spport key point. As shown in the following example:

At this point, the study on "how to diagnose unmapped key points" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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