What is the function of a buffer circuit?
-
to provide an output that is inverted from that on the input -
to provide an output that is equal to its input -
to clean up the input -
to clean up the output
What is the preset condition for a ring shift counter?
-
all FFs set to 1 -
all FFs cleared to 0 -
a single 0, the rest 1 -
a single 1, the rest 0
The primary purpose of a three-state buffer is usually:
-
to provide isolation between the input device and the data bus -
to provide the sink or source current required by any device connected to its output without loading down the output device -
temporary data storage -
to control data flow
Which is not characteristic of a shift register?
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Serial in/parallel in -
Serial in/parallel out -
Parallel in/serial out -
Parallel in/parallel out
What is the difference between a ring shift counter and a Johnson shift counter?
-
There is no difference. -
A ring is faster. -
The feedback is reversed. -
The Johnson is faster.
To keep output data accurate, 4-bit series-in, parallel-out shift registers employ a ________.
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divide-by-4 clock pulse -
sequence generator -
strobe line -
multiplexer
What is a recirculating register?
-
serial out connected to serial in -
all Q outputs connected together -
a register that can be used over again
When is it important to use a three-state buffer?
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when two or more outputs are connected to the same input -
when all outputs are normally HIGH -
when all outputs are normally LOW -
when two or more outputs are connected to two or more inputs
On the fifth clock pulse, a 4-bit Johnson sequence is Q0 = 0, Q1 = 1, Q2 = 1, and Q3 =On the sixth clock pulse, the sequence is ________.
-
Q0 = 1, Q1 = 0, Q2 = 0, Q3 = 0 -
Q0 = 1, Q1 = 1, Q2 = 1, Q3 = 0 -
Q0 = 0, Q1 = 0, Q2 = 1, Q3 = 1 -
Q0 = 0, Q1 = 0, Q2 = 0, Q3 = 1
The bit sequence 0010 is serially entered (right-most bit first) into a 4-bit parallel out shift register that is initially clear. What are the Q outputs after two clock pulses?
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0000 -
0010 -
1000 -
1111
What is a shift register that will accept a parallel input, or a bidirectional serial load and internal shift features, called?
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tristate -
end around -
universal -
conversion
On the third clock pulse, a 4-bit Johnson sequence is Q0 = 1, Q1 = 1, Q2 = 1, and Q3 =On the fourth clock pulse, the sequence is ________.
-
Q0 = 1, Q1 = 1, Q2 = 1, Q3 = 1 -
Q0 = 1, Q1 = 1, Q2 = 0, Q3 = 0 -
Q0 = 1, Q1 = 0, Q2 = 0, Q3 = 0 -
Q0 = 0, Q1 = 0, Q2 = 0, Q3 = 0
A bidirectional 4-bit shift register is storing the nibbleIts 
input is HIGH. The nibble 1011 is waiting to be entered on the serial data-input line. After three clock pulses, the shift register is storing ________.
-
1101 -
0111 -
0001 -
1110
A 4-bit ring counter is loaded with a singleThe frequency of any given output is ________.
-
the same as the clock -
twice the clock frequency -
one-half the clock frequency -
one-fourth the clock frequency
Assume a LOW logic level is placed on the SHIFT/LOAD input of a 74195 shift register. The output will change ________.
-
immediately -
if the CLOCK is also LOW -
on the next clock leading edge -
depending on the J and K inputs
Shifting a binary number to the left by one position is equivalent to ________.
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multiplying by two -
multiplying by four -
dividing by two -
dividing by four
Assume a 4-bit Johnson counter is initially cleared. After the first clock pulse the output isAfter the next clock pulse the output will be ________.
-
0011 -
0010 -
1000 -
0110
A type of shift register in which the Q or Q output of one stage is not connected to the input of the next stage is ________.
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parallel in/serial out -
serial in/parallel out -
serial in/serial out -
parallel in/parallel out
A Johnson counter, constructed with N flip-flops, has how many unique states?
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N -
2N -
2N -
N2
Assume a 4-bit parallel in/serial out shift register is loaded with a binary number. How many clock pulses are required after the parallel load has occurred before the first bit in the sequence appears on the serial output line?
-
0 -
1 -
2 -
3