Number 2 (Y)
Number 1 (X)
Let R = X + Y
(contains Number 1)
(contains Number 2)
(Result of Number 1 + Number 2)
Step 1. Control unit fetches instruction
Step 2. Control unit interprets the instruction and sends the 2 numbers to be added into the appropriate registers in the ALU.
Step 4. Result is stored back in memory.
Step 3. Control unit executes the instruction by directing the ALU to add the 2 numbers in the registers 1 and 2 then store the result in the accumulator.