| 5. |
(a) |
(i) How many flip-flops are required to build
a binary counter circuit that can count from 0 to 1023? |
[1] |
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10 |
[1] |
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(ii) What would be the MOD number of the
counter? |
[1] |
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1024 |
[1] |
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(iii) If the counter is initially at zero,
what count will it hold after 2060 pulses? |
[2] |
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12 |
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award one mark for wrong
answer with some correct calculation |
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[2
marks] |
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(b) Draw a 3-bit asynchronous down
counter using negative edge triggered JK flip flops. (Label all of the inputs and outputs
clearly.) |
[8] |
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All J, K
inputs are high |
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award one mark
for each of the following features: |
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correct number of FFs |
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correct location of
outputs |
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correct connection
from one flip flop to the next |
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all j inputs high |
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all k inputs high |
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negative edge
triggering |
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first clock input |
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other output left
unconnected |
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[8
marks] |
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(c) Draw the circuit diagram for
the synchronous parallel transfer of data from one 3-bit register to another using
positive edge triggered JK flops. (Label all of the inputs and outputs clearly.) |
[8] |
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award one mark
for each of the following features: |
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correct number of FFs
in first register |
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correct number of FFs
in second register |
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correct labelling of
outputs in first register |
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correct labelling of
outputs in second register |
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all J inputs for
second connected to outputs in first |
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all K inputs for
second connected to negated outputs in first |
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positive edge
triggering |
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clock not connected to
first register |
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Note that
there are other ways of solving this problem: some care may be required in evaluating
alternative answers. |
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[8
marks] |
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