Lecture 6 Objectives

KNOW:

• The difference between a combinational circuit and a sequential circuit
• What is meant by the "state" of the system
• That a finite state machine can be used to represent the behavior of a system with state
• That a finite state machine can be implemented by a sequential circuit

BE ABLE TO:

• Describe the operation of the R-S latch and the gated D-latch
• Understand the logic diagram for a small memory (such as the one pictured in Figure 3.21)
• Draw a finite state machine for a small system
• Use a state transition table to implement a finite state machine with a sequential circuit

Sample Exam Question:

In a brief paragraph (three or four sentences), describe how the gated D-latch works. Your description should specifically mention the values of D, WE, S, and R. (A diagram of the gated D-latch can be found in Figure 3-19.)