Q8a

A single bus CPU consists of four general purpose register, namely, $R0, \ldots, R3, \text{ALU}, \text{MAR}, \text{MDR}, \text{PC}, \text{SP}$ and $\text{IR}$ (Instruction Register). Assuming suitable microinstructions, write a microroutine for the instruction, $\text{ADD }R0, R1$.