Can someone help with the code and testbench please! Thank you in advance!!! :D

Design a 16-bit Arithmetic Unit which consists of one 16-bit adder, 16-bit subtractor, 16-bit incrementer, and 8-bit multiplier. You can use below entity declaration for your design. The least-significant 8 bits of A and B are used as inputs of the multiplier. The output will be 16 bits. The operation of arithmetic unit depends on the value of input Select. 8-bit multiplier has only 16 bits as output, the carry out of arithmetic unit must be 0 when a multiplication operation is performed. The carry out of this unit must be 1 after incremental operation is performed when current A 's value is 0 xFFFF (Overflow case) For example: if A=0xFFFF, then A=A+1=00000 and carry out =1 The following table describes this unit's behavior: Report: VHDL code and waveforms