Copyright © Dean Johnson 2008 (johnson@wmich.edu)

Quiz #8 Clocks and Flip-Flops

This quiz covers flip-flops and clocks. Please refer to the lecture notes for background material covering this subject. (Go back to homepage.)


  1. What frequency clock source will produce clock waveforms having a period equal to 5 us (5 microseconds)?
    Note:    M = 10^6 
             k = 10^3 
             m = 10^-3 
             u = 10^-6 
    

    1. .2 MHz
    2. .5 MHz
    3. 10 MHz
    4. 2 kHz
    5. 5 kHz

  2. The logic circuit shown represents most closely the architecture of a

    1. Simple Latch
    2. SR Latch with Enable
    3. D Latch with Enable
    4. D Flip-Flop
    5. JK Flip-Flop




  3. 2 kHz (2 kiloHertz) clock will produce clock waveforms having which of the following period values .
    Note:    M = 10^6 
             k = 10^3 
             m = 10^-3 
             u = 10^-6 
    

    1. T = 2 us
    2. T = 5 us
    3. T = 2 ms
    4. T =.5 ms
    5. T =.5 us

  4. Which of the following will correctly complete the JK flip-flop truth table shown below?
                                           J K Qn | Qn+1 
                                           -------|-----
       1) 0   2) 0   3) 0   4) 0   5) 1    0 0 0  |  ? 
          1      1      0      0      1    0 1 1  |  ? 
          1      0      1      1      0    1 0 1  |  ? 
          0      0      1      0      1    1 1 1  |  ? 
    

  5. Which of the following will correctly complete the D flip-flop truth table shown below?
                                             D Qn | Qn+1 
                                            ------|----- 
       1) 1   2) 1   3) 0   4) 0   5) 0      0 0  |  ?  
          1      1      0      0      1      0 1  |  ? 
          1      0      0      1      1      1 0  |  ? 
          1      1      1      1      0      1 1  |  ? 
    

  6. Which of the following will correctly complete the JK flip-flop truth table shown below?
                                           J K Qn | Qn+1 
                                           -------|-----
       1) 0   2) 0   3) 0   4) 0   5) 1    0 0 0  |  ? 
          1      1      0      0      1    0 1 0  |  ? 
          1      0      1      1      0    1 0 0  |  ? 
          0      0      1      0      1    1 1 0  |  ? 
    

  7. Qn is stable over which of the following clock regions?

    1. Region A
    2. Region B
    3. Region C
    4. Region D
    5. Region E

  8. Refering to the clock regions of the last question, during what region should the inputs of a flip-flop be established to initiate a output change from Qn to Qn+1?

    1. Region A
    2. Region B
    3. Region C
    4. Region D
    5. Region E

  9. The PRE and CLR (preset & clear) inputs of a master/slave JK flip-flop overide the JK inputs

    1. Unconditionally.
    2. Only after the clock input goes high.
    3. Only after the clock input goes low.
    4. Only if J = 0 and K = 0.
    5. Only if J and K are not connected to anything.