Synchronizing to Simulations Using VPI Callbacks

Summary

This chapter has presented one of the more powerful aspects of the VPI routines and the Programming Language Interface—the ability to synchronize PLI application calls with different types of simulation activity. The examples presented in this chapter have shown ways to synchronize PLI applications with the start of simulation, with the end of a simulation time step, with future simulation times, and with logic value changes. Another important topic presented in this chapter was how to allocate and store instance-specific data, and share this data between the different routines that make up a PLI application. A critical consideration in sharing and preserving data is that the data must be instance specific. This means unique storage for the data must be allocated for each instance of a system task or system function.

The next chapter presents how the PLI can be used to interface C language models with Verilog simulation. This interface will utilize many of the concepts which were presented in this chapter.