Demonstration of digital circuit analysis in the classroom

Personal computer software presently used in a senior-level digital electronics design course is described. Dedicated computer solutions are written for classic circuits to decrease the solution time and provide an interactive program operation. In this way, various design choices are explored in real time during the classroom lecture and the dependence of the circuit performance upon component values is shown. An overview is given of how this software has been used to illustrate rapidly the convergence of the design process to an `optimal´ solution as component values are changed by the instructor during the lecture. The comparison of new results to the previous results can be done with this software in two ways. The graphical display can be captured into an array before the next design iteration is performed. Then this previous solution can be recalled and superimposed on the present display as a slowly flashing display. A 50% duty cycle, two-second display of this stored image produces a pleasing result. Numeric values of the observed performance can be stored and recalled in tabular form. Large block characters are used for this display page. The current operation can thus be compared to those previously saved. Function key selection updates or clears these stored results. Function keys also select the display of this tabular summary, the input-output graphical plot, or the flashing comparison graphical plot