Consider ADDI instruction from LEGv8

ADDI X2, X1, #8 // Add 8 to X1 and store result in X2

The binary representation of this instruction is shown below

opcode

Immediate

Rn

Rd

10 bits 12 bits 5 bits 5bits

In the case of our example, Opcode = 1000000100 (10 bits)

Immediate = 0000 0000 1000 (12 bits)

Rn = 00001 (5 bits representing X1)

Rd = 00010 (5 bits representing X2)

Show the values for all the control signals (each signal is either a zero or a one), and the ALU control (which ALU operation is executed).

For this (and most of the problems) we will use the datapaths and control paths shown on page 282 (figure 4.23)- also shown below.

Also, we will use the following for ALU control (to specify which operation is performed by the ALU

ALU Control	Function
0000	AND
0001	OR
0010	add
0110	subtract
0111	pass input b
1100	NOR

Add MI LI ALU result Shift Uncondbranchleft 2 Instruction 131-21] RegWrite Instruction [9-5 nstruction [20-1 PCaddress register 1 Reed data! Instruction Tregister 2 31-0 Write Read register data 2 Write data Registers memoryon4-0 Write Data dala Instruction [31-0) 32 sign- 64 ALU xtend Add MI LI ALU result Shift Uncondbranchleft 2 Instruction 131-21] RegWrite Instruction [9-5 nstruction [20-1 PCaddress register 1 Reed data! Instruction Tregister 2 31-0 Write Read register data 2 Write data Registers memoryon4-0 Write Data dala Instruction [31-0) 32 sign- 64 ALU xtend