Consider the basic single$-$cycle MIPS datapath that implements a subset of the MIPS instruction set $($add$,$ subtract, and, or$,$ Iw$,$ sw$,$ beq, jump$).$ We would like to modify this datapath to implement the swapm instruction:

Instruction: swapm rs$,$ rt

Interpretation: R$[$rt$]=$ M$[$R$[$rs$]$ & M$[$R$[$rs$]]=$ R$[$rt$]$

a$)$ Which existing blocks will we use? Do we need to add new functional units or modify exisiting ones? Use the figure to highlight the active datapath and add any required extra signals$/$compents

b$)$ Do we need new control signals to support this instruction? Fill table with control signal values that will ensure the correct flow of data for swapm.

RegDst

ALUSrc

ALUOp

MemRead

MemWrite

MemtoReg

RegWrite

Branch

Jump