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10.12 DESIGN OF SIMPLE SYNCHRONOUS STATE MACHINES 471

Algorithm 10.1:Z) -» T K-map Conversion (Refer to Eq. 10.19)

(1) For all that is NOT A in the D A K-map, transfer it to the T A K-map directly (AT A),
(2) For all that is A in the D A K-map, transfer it to the T A K-map complemented (AT A).
(3) Repeat steps (1) and (2) for the DB -*• T B and DC —* TC, etc., K-map conversions.

Notice that the word "complemented," as used in the map conversion algorithm, refers to
the complementation of the contents of each cell in the domain indicated.

10.12.2 Design of a Sequence Recognizer: D-to-JK K-map Conversion
It is required to design a sequence recognizer that will issue an output any time an overlap-
ping sequence ... 01101... is detected as indicated in Fig. 10.60a. To do this a choice is
made between the Moore or Mealy constructions shown in Figs. 10.60b and 10.60c, respec-
tively. For the purpose of this example, the Mealy construction is chosen. Let the external

X — »
Sequence
, Recognizer
CK — c

X ---0 1 1 01 1 01 00- "
I \
z z

(a)
N > x
y~f~~ v
( 111 JZAT
Mealy version
Moore version
(b) (c)

FIGURE 10.60
A simple sequence recognizer for an overlapping sequence • • -01101- • -.(a) Block diagram and sample
overlapping sequence, (b) Moore FSM representation, (c) Mealy FSM representation.