Page 1117 - The Mechatronics Handbook

TABLE 41.4 Primitive Flow Table (PFT) for Asyncronous Design Example

Next State / Output
Previous Present
Input State X X 1 00 01 11 10
2
00 1 1 / 0 2 / - - / - 3 / -

01 2 1 / - 2 / 0 4 / - - / -

10 3 1 / - - / - 5 / - 3 / 0

11 4 - / - 6 / - 4 / 0 3 / -

11 5 - / - 6 / - 5 / 1 3 / -

01 6 1 / - 6 / 1 4 / - - / -

TABLE 41.5 Reduced Flow Table (RFT) for Asyncronous Design Example
Next State / Output
Present State
X 2X 1 00 01 11 10
A A A
/ 0 / 0 C / - B / -

B A / - C / - B / 1 B / 0

C
A / - C / 1 C / 0 B / -

2
3 4,5

4 2,6 2,6 4,5
5 2,6 2,6
4,5
2,6 4,5
6 4,5
FIGURE 41.11 Implication table for the PFT. 1 2 3 4 5
input the stable states either go to the same next states and have the same outputs, or at least
they do not contradict. Hence, the corresponding merger diagram shows that the PFT can be
reduced to a 3-state flow table. The new reduced final states in the flow table are then the three
nonbinary states, A, B, and C. State A is (1, 2), state B is (3, 5), and state C is (4, 6). Table 41.5
shows the reduced flow table. In this flow table, we have more than one stable state per row. Note
that when states are combined, the “don’t care” entries are replaced with the actual states under
a given input.

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