Analysis of Sequential Systems Chapter 6 Analysis of Sequential Systems Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

CE6. A system with one input x and one output z such that z = 1 iff x has been 1 for at least three consecutive clock times. State: what is stored in memory. It is stored in binary devices, but the information to be stored is not always naturally binary. Timing trace: a set of values for the input and output (and sometimes the state or other variables of the system, as well) at consecutive clock times.

State table: shows for each input combination and each state, what the output is and what the next state is, that is, what is to be stored in memory after the next clock. State diagram (or state graph): a graphical representation of the state table.

P = (S + Q)´ Q = (R + P)´

q* = S + R´q

q* = J´q + K´q

D1 = q1 q´2 + x q´1 D2 = xq1 z = q´2

JA = x KA = xB´ JB = KB = x + A´ z = A + B

D1 = xq1 + xq2 D2 = xq´1q´2 z = xq1