Design a complete single-cycle datapath and a control unit for a machine that has only 4 instructions. The instructions are:

add R1, R2, R3 # R1=R2+R3

load R1, imm (R2) # R1= Memory[imm + R2]

store R1, imm (R2) # Memory[imm + R2]=R1

beq R1, R2, imm # if (R1=R2) then go to location PC + 1 + SignExt(imm)

where imm is a 2s complement number.

Assume each instruction has 8 bits; two of them are for the op-code. Also assume that there are only 4 registers each consists of 8 bits; and a data memory unit and an instruction memory unit, each having 256 bytes. The size of a byte is 8 bits and is equal to the size of an instruction.

a. Define the instruction formats.

b. Draw a complete datapath (including the details of the Next Address Logic unit) which is able to perform the above operations; be sure to include Register File, ALU, Memory Units, PC, control signals, extra buffers or registers (if needed), number of wires from one component to the other, and any other components that you may need.

c. Design the control unit and draw the minimized logic diagram for it.