Answer Happy

Study Figure 4.11, on page 270, of your text. What is thepurpose of the "Shift left 2" component for the B-typeinstruction?
PC Read address Add Instruction Instruction memory Read register 1 Read register 2 Registers Read data 2 Write register Write data RegWrite Read data 1 32 Sign- extend 64 Shift left 2 ALUSrc MUX ALU Add result PCSrc ALU operation Zero ALU ALU result MEX Address MemWrite MemRead Read data Write Data data memory MemtoReg MUX FIGURE 4.11 The simple datapath for the core LEGV8 architecture combines the elements required by different instruction classes. The components come from Figures 4.6, 4.9, and 4.10. This datapath can execute the basic instructions (load-store register, ALU operations, and branches) in a single clock cycle. Just one additional multiplexor is needed to integrate branches. The support for unconditional branches will be added later.