Concurrent Processes

Most of the behavioral modeling statements discussed to this point have been demonstrated using single process examples. These statements are part of the body of an always statement and are repetitively executed in sequential order. They may operate on values that are inputs or outputs of the module or on the module’s internal registers. In this chapter we present behavioral modeling statements that by their definition interact with activities external to the enclosing always. For instance, the wait statement waits for its expression to become true as a result of a value being changed in another process. As in this case and the others to be presented here, the operation of the wait statement is dependent on the actions of concurrent processes in the system.