ABSTRACT
The logic networks consist of two different types of logic elements: the elements that operate on data values, and the elements that contain a state. The elements that operate on data values are all combinational, which means that their outputs depend only on the current inputs. Given the same input, a combinational element always produces the same output. Other elements in the logic networks are not combinational, but instead contain a state. An element contains a state if it has some internal storage. These elements are called state elements. In a state element, the required inputs are the data values to be written into the element, and the clock, which determines when the data value is written. The output from a state element provides the value that was written in an earlier clock cycle. The ability to store data during the time between the write-enabling signal is a crucial property of a digital system.
