Chapter 3 — Sequential Logic Design

Unlike combinational circuits, sequential logic circuits have outputs that depend not only on current inputs, but also on the circuit’s stored past state. This ability to “remember” makes sequential logic the foundation for registers, counters, finite state machines (FSMs), and processor control units.

In computer systems, instruction-by-instruction execution, program counter updates, and saving/restoring register contents all rely on stable state storage and orderly state transitions under a clock signal.

This chapter focuses on three representative sequential modules:

• Latches and flip-flops
• Register files
• Finite state machines (FSMs)