SYEN 3330 Digital Systems Chapter 6 Part 3

SYEN 3330 Digital Systems Chapter 6 – Part 3 SYEN 3330 Digital Systems Jung H. Kim 1

Overview of Chapter 6 • Types of Sequential Circuits • Storage Elements – Latches – Flip-Flops • Sequential Circuit Analysis – State Tables – State Diagrams • Sequential Circuit Design – – Specification Assignment of State Codes Implementation HDL Representation SYEN 3330 Digital Systems 2

Sequential Circuit Analysis Inputs Combinational Logic Storage Elements State Outputs Next State CLK SYEN 3330 Digital Systems 3

Example (from Fig. 6 -17) SYEN 3330 Digital Systems 4

Example (Fig. 6 -17) (Continued) SYEN 3330 Digital Systems 5

Example (Fig. 6 -17) (Continued) • Where in time are inputs, outputs and states defined? 1 0 0 0 0 1 SYEN 3330 Digital Systems 6

Example (Fig. 6 -17) (Continued) • Where in time are inputs, outputs and states defined? 1 0 0 0 0 1 SYEN 3330 Digital Systems 7

State Table Characteristics SYEN 3330 Digital Systems 8

Example: State Table (Fig. 6 -17) The STATE TABLE can be filled in using the next state and output equations. SYEN 3330 Digital Systems 9

Alternate State Table Format An alternate format just shows the next state and output as a function of the current state, but broken out by input. SYEN 3330 Digital Systems 10

State Table Characteristics SYEN 3330 Digital Systems 11

State Diagrams SYEN 3330 Digital Systems 12

State Diagram (Example) SYEN 3330 Digital Systems 13

Flip-Flop Input Functions SYEN 3330 Digital Systems 14

Analysis with Other Flip-Flops SYEN 3330 Digital Systems 15

Characteristic Tables (Review 6 -7) SYEN 3330 Digital Systems 16

JK Flip-Flop Circuit Analysis SYEN 3330 Digital Systems 17

JK Flip-Flop Analysis (Cont. ) SYEN 3330 Digital Systems 18

JK Flip-Flop, Next State SYEN 3330 Digital Systems 19

JK Flip-Flop, Next State SYEN 3330 Digital Systems 20

Review: Sequential Circuits SYEN 3330 Digital Systems 21

Moore and Mealy Models Sequential Logic, or Sequential Machines are also called Finite State Automata. Two formal models exist: SYEN 3330 Digital Systems 22

Moore and Mealy Example SYEN 3330 Digital Systems 23

Moore and Mealy Example Tables SYEN 3330 Digital Systems 24