Digital logic refers to the pieces of hardware used to construct digital systems such
as computers. As we have seen, Boolean algebra is an important tool in digital circuit
design; there is a direct relationship between Boolean functions and the gates used to
implement combinatorial digital circuits. We have also seen that Boolean logic values
can be described using truth tables.
A clock is a straightforward mechanism that emits pulses at regular intervals. A
clock allows a digital circuit to change without requiring inputs to change, and can be
used to provide synchronization among multiple parts of a circuit.
Although we think of digital logic from a mathematical point of view, building
practical circuits involves understanding the underlying hardware details. In particular,
besides basic correctness, engineers must contend with problems of power distribution,
heat dissipation, and clock skew.