Instruction sequencing
Example – an instruction to add the contents of two registers (Rx and Ry) and place result in a third register (Rz)
Step 1: get the ADD instruction from memory into an instruction register
Step 2: decode instruction
- instruction in IR has the code of an ADD instruction
- register indices used to generate output enables for registers Rx and Ry
- register index used to generate load signal for register Rz
Step 3: execute instruction
- enable Rx and Ry output and direct to ALU
- setup ALU to perform ADD operation
- direct result to Rz so that it can be loaded into register