1. Hazards
9.6

2. Figure 9.61 Definition of hazards1 1
(a) Static hazard 1 1 1
(b) Dynamic hazard
Figure Definition of hazards

3. Figure 9.62 An example of a static hazard3
(a) Circuit with a hazard 1 2 p q x 1 2 3 00 01 11 10
(b) Karnaugh map x 3 1 2 f
(c) Hazard-free circuit
Figure An example of a static hazard

4. Figure 9.63 Two-level implementation of master-slave D flip-flopC Y m s y p q r
(a) Minimum-cost circuit Q D C Y m s y
(c) Hazard-free circuit Q 00 01 11 10 1
(b) Karnaugh maps for Y m
and s
in Figure 9.6 a y CD
Figure Two-level implementation of master-slave D flip-flop

5. Figure 9.64 Function for Example 9.172 3 4 00 01 11 10 d
Figure Function for Example 9.17
para resolver o hazard, não há necessidade de cobrir os “don´t care”, apenas os “1s” adjacentes

6. Figure 9.65 Static hazard in a POS circuitx 3
(a) Circuit with a hazard 2 1 p q x 1 2 3 00 01 11 10
(b) Karnaugh map x 3 2 1 f
(c) Hazard-free circuit
Figure Static hazard in a POS circuit

7. Figure 9.66 Circuit with a dynamic hazardx 2 3 4 , 1 b a c d f
One gate delay
(b) Timing diagram
(a) Circuit x 2 1 3 4 b a c d f
Figure Circuit with a dynamic hazard