METHOD AND APPARATUS FOR INTERACTIVELY DISPLAYING SIGNAL INFORMATION DURING COMPUTER SIMULATION OF AN ELECTRICAL CIRCUIT

A computer system simulator concurrently models both processor operation and signal logic behavior and provides a high degree of user interaction and flexibility in the observation and control of signal values and memory contents during the execution of a simulation. During simulation, source equations for signals can be requested for display either through direct input of a signal name or through graphical interface with the simulation display. Signal equations can in this manner be traced back through several levels, which conveniently provides important information during the observation and modification of signal values. Memory areas may be associated with a processor and loaded with data to be executed by that processor during the simulation. The data can be displayed in both numerical and assembly code mnemonic form, and may also be modified by entering numbers or assembly instructions. The simulated processor execution may thus be interactively modified during the simulation. Additionally, the ability to step the simulation backwards through time, and then forward again, is provided.