Design a $4-$bit Arithmetic Unit that can perform different arithmetic operations

based on the mode selected. The unit should have two unsigned $4-$bit inputs $($A

and B$)$ and should be able to perform addition, subtraction, multiplication, and

division. Your circuit must also output flags indicating the result's zero and carry

status.

Mode of Operation:

$$ Mode $00$: Perform $4-$bit addition of A and B$.$

$$ Mode $01$: Perform $4-$bit subtraction of B from A$.$

$$ Mode $10$: Perform $4-$bit multiplication of A and B $($ignore overflow$).$

$$ Mode $11$: Perform integer division of A by B $($output quotient and

remainder$).$

Constraints:

$$ For multiplication and division, you can use shift registers.

$$ The circuit must use no more than $5$ registers for intermediate storage.

$$ Outputs should include carry and zero flags.

Inputs

Pin Size $($in bits$)$ Explanation

A $4$ Unsigned $4-$bit input A$.$

B $4$ Unsigned $4-$bit input B$.$

Mode $2$ Mode selection:

$00$ for add,

$01$ for subtract,

$10$ for multiply,

$11$ for divide.

clkIn $1$ Connect to the clock

ports of

registers$/$flip$-$flops.

Outputs

Pin Size $($in bits$)$ Explanation

Result $4$ The result of the

arithmetic operation.

Remainder $4$ The remainder when

dividing A by B $($valid

only for division$).$