Create a computational unit that can compute the following operations on $4$

bit operands:

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$2$ TEST CASES

$1.$ AND

$2.$ OR

$3.$ NAND

$4.$ NOR

$5.$ Addition

$6.$ Subtraction

$7.$ Greater than

$8.$ Less than

First test the computation unit for all operations. After verifying the unit

works properly for all operations, then instantiate the component $3$ times in

the arrangement shown in Fig. $1.$ Make sure to use the same input and output

names shown in Fig. $1,$ but note that the figure is representational and does

not show all inputs and signals you might need to implement the design.

$2$ Test cases

To test the computation unit, use the inputs $1001$ and $0101$ for the first

test case and $0110$ and $1001$ for the second test case. Calculate the ex$-$

pected values and then record the simulated outputs in a table for comparison

to verify that they match.

To test the overall design, use the following test cases and similarly record

the calculated vs simulated outputs in a separate table for comparison.

Case $1$:

$$ A: $1011,$ B: $1100,$ C: $1001,$ D: $0011$

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$3$ FORMATTING

$$ CU #$1$: OR$,$ CU #$2$: ADD, CU#$3$: GREATER THAN

Case $2$:

$$ A: $1011,$ B: $1100,$ C: $1001,$ D: $0011$

$$ CU #$1$: AND, CU #$2$: LESS THAN, CU#$3$: SUBTRACT