Quiz 5.1

DIRECTIONS: Read each question carefully. Then click on the dot next to the answer that most closely fits the question. Try to answer all questions on this quiz and when you are done, click on the grade me button at the bottom.

Coverage: Section 5.1

  1. Which truth table represents NOR? 
               A    B   |    ?
               ---------+--------
               0    0   |    0
               0    1   |    1
               1    0   |    1
               1    1   |    1


               A    B   |    ?
               ---------+--------
               0    0   |    1
               0    1   |    0
               1    0   |    0
               1    1   |    0


               A    B   |    ?
               ---------+--------
               0    0   |    1
               0    1   |    1
               1    0   |    1
               1    1   |    0

  1. How many bits does a latch store at any given moment in time?
1
2
4

  1. What does the R stand for in the name S-R latch?
resistor
request
refresh
reset

  1. In the SR latch below, all the lines have certain values at the present moment. Suppose line S changes to 0 and all the wires stabilize after a few nanoseconds. What value will be on the Q' wire?

GIFs/SR_latch_1.gif
0
1

  1. In the SR latch below, all the lines have certain values at the present moment. Suppose line R changes to 1 and all the wires stabilize after a few nanoseconds. What value will be on the Q wire?

GIFs/SR_latch_2.gif
0
1

  1. If you want to store the value 0 into an S-R latch, what value must you put on which wire?
put 1 on S wire
put 0 on S wire
put 1 on R wire
put 0 on R wire

  1. What action would cause the S-R latch to enter an indeterminate state?
put 1 on S wire, then put 0 on S and 1 on R
put 0 on both S and R wires and then put 1 on both
put 1 on both S and R wires and then put 0 on both

  1. What do we call a circuit that randomly chooses between 0 and 1?
arbiter
memory cell
multiplexor
latch

  1. What trick does a latch use to enable it to act as a memory cell?
NOR gates
feedback
two distinct outputs
two distinct inputs