of signals the simulation data is shown as a series of transactions write transactions such as at 240 are shown as dotted lines and read transactions such as shown at 242 are shown as solid lines throughput is shown along the y axis and time is indicated along the x axis thicker lines generally mean there is a grouping of many transactions so close in time that at the current zoom level they cannot be distinguished of course a zoom option may be used to focus on particular transactions as can readily be seen the view of fig8 is much easier to read than that of fig4 and allows the designer to obtain a better overall system view of the flow of data fig9 shows a flowchart of a method for implementing model extraction 14 fig1 in process box 300 input files are received related to protocol information model description and simulation data for the circuit the protocol information is provided by the user and is stored in the protocol library 44 the model description is also provided by the user and includes an interface of the circuit model describing the input output ports and the lasting state description of the circuit model that describes the internal states elements thereof the simulation data may be simulation data 48 see fig3 or simulation data at the transaction level 56 fig3 in process box 302 using the input files an abstract model is generated that approximates the circuit.