1. Latches and Flip-Flops
DIGI-210 Review
Latches and Flip-Flops
©Paul Godin
Created September 2007
Last edit Sept 2009

2. Complete the timing diagramsQ S S Q En R Q R En S R Q

3. Complete the timing diagrams

4. Complete the timing diagram and fill in the blanks

5. Determine input sequences to make output 1 (assume all inputs start low)

6. Find the circuit faults, if any (1)

7. Find the Circuit Faults, if any (2)

8. Find the Circuit Faults, if any (3)

9. Determine the Latch (1)
Identify the latch represented in each of the 3 sets of inputs and output. Consider the following:
Are the inputs active high or active low.
Which input is S and which is R
Is the output Q or Q’
Note: there may be more than one answer that fits

10. Determine the Latch (2)
The timing diagrams on the right has 2 inputs and 4 outputs.
For each of the outputs, determine the input 1 and input 2 status, including:
The active input state (high or low)
Which input is S and which is R,
The output (Q or Q’)
There may be more than one answer.