Single Cycle Datapath and Control

Objectives. Learn how to enhance the datapath and control for a single cycle implementation of a simple ALU.

Put all your answers on these two sheets.

Below is a table that indicates which control lines are set for each type of instruction for the single$-$cycle implementation shown in Figure $4\mathrm{.}24$ of your textbook, which is also shown on the following page. Indi$-$ cate the setting for each control line to support the addiu instruction, which should not require any modifications to the datapath. Use an $x$ when the value for a control line does not matter. $(40$ points$)$

Modify the datapath and control for the single$-$cycle implementation shown on the following page to add the instruction jal $($jump and link$),$ which like a $j($jump$)$ instruction transfers control to the specified address, but also updates $$ra($$$3l)$ with the $PC+4$ value. $(60$ points$)$

$\backslash$table$[[$Instruction$,\backslash$table$[[$Reg$],[$Dst$]],\backslash$table$[[$ALU$],[$Sre$]],\backslash$table$[[$Memto$],[$Reg$]],\backslash$table$[[$Reg$],[$Write$]],\backslash$table$[[$Mem$],[$Read$]],\backslash$table$[[$Mem$],[$Write$]],$Branch,Jump,$\backslash$table$[[$ALU$],[$Op$1]],\backslash$table$[[$ALU$],[$Op$0]]],[$R$-$format,$1,0,0,1,0,0,0,0,1,0],[$Iw$,0,1,1,1,1,0,0,0,0,0],[$sw$,x,1,x,0,0,1,0,0,0,0],[$beq$,x,0,x,0,0,0,1,0,0,1],[$j$,x,x,x,0,0,0,x,1,x,x$