Logic Design Review

A digital logic design course covers the topics of combinational and sequential digital circuits. We can review the distinction of these circuit types by showing simple Logisim examples.

For studying computer organization, we are particularly interested in synchronous sequential circuits, which make it easy for us to analyze the propagation delay and determine the clock period requirements.

One topic that might not have been paid enough attention in a logic design course is the very useful tri-state buffer. The Logisim wire coloring is helpful in showing the cases of “floating”—a wire that is not driven, and “error”—a wire that is driven to opposite values.