1. A computing system, comprising: one or more memories comprising computer-readable code; and one or more processors, which in response to execution of the computer readable code cause the computing system to perform the following: running an environment for designing operation of circuitry, wherein running the environment comprises performing at least the following for providing simulations and evaluations of one or more user-defined modules of circuitry comprising one or more pipeline stages in a pipeline: automatically generating a model of the pipeline by using a pipeline block diagram, where the model is generated in a high-level modeling language able to perform simulations of circuitry with the pipeline; automatically generating an interface between the one or more user-defined modules and the generated model of the pipeline, the interface comprising access to the pipeline, wherein the pipeline access allows the one or more user-defined modules to interact indirectly; performing evaluation of the one or more user-defined modules using the automatically generated model of the pipeline and the automatically generated interface; and directly connecting the user-defined modules to ports allowing the one or more user-defined modules to interact directly to replace the pipeline access between the one or more user-defined modules and the generated model of the pipeline.