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How can I make complex RENO flowcharts easier to maintain and debug?



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Complex flowcharts that are easy to maintain and debug are a result of careful planning and good design. Here are some general tips for designing RENO flowcharts:

1. Break down a complex flowchart into subcharts

If the flowchart is complex, first create a top-level flowchart that models the high-level processes in the analysis, and then create separate subcharts to model the lower-level details or subprocesses.This has the following advantages:

2. Give all blocks and resources short and meaningful names

Unique and meaningful names can help you to identify the role of a block or resource and verify whether the output is correct. You can also use the Comments fields to document the purpose, limitations, assumptions and other relevant information.

3. Use a consistent flow direction

The most widely used directions are top to bottom and left to right. Whenever possible, don’t reverse the direction of flow unless it is actually part of the process being illustrated.

The following example shows a flowchart with inconsistent flow direction. At first glance, it is not immediately clear where the flowchart starts and where it ends.

The following picture shows the same flowchart, but with the blocks rearranged to improve readability.

4. Don’t use the same resource for different purposes

More often than not, resources are defined based on a specific set of assumptions. Avoid reusing the same resource model in another analysis that has different assumptions. Instead, create a new resource with a different name specifically for that purpose.

Remember that Synthesis resources are shared by all flowcharts in the same project. Any changes you make to a resource’s properties will be applied everywhere that the resource is used.

5. Don’t reuse an existing resource name for another type of resource

Resources are referenced by the blocks in the flowchart; therefore, their names should be unique to prevent mismatched references. You can ensure that all resources in a project use unique names by selecting the Enforce RENO compliance check box in the Synthesis Setup window (File > Synthesis Setup).

6. Use the built-in debugger

The Debug utility logs the output value of every resource and block as you step through the flowchart. This helps you to verify the output of a flowchart. To use the debugger, click Debug on the control panel of the flowchart.

The following picture shows an example of a debug session.

The Debug utility works especially well with RENO subcharts. You can choose to exclude any subchart from a debug session (and debug them separately at a later time) by choosing the Step Over command.

To debug a subchart during the session, choose the Step Into command.

To immediately step out of a subchart and continue the debug session in the parent flowchart, use the Step Out command.