11. The Instruction Set Architecture

• ISA is a set of instructions that can be carried out by the CPU.

• ISA includes instructions and operands.

• When we say instruction, it could be

  • assembly instruction mnemonic, describing the operation: jmp initialize

  • disassembly instruction showing an address: jmp 0040106E

  • machine-level instruction encoding: hex EB 21 (binary 1110101100100001)

  • microcode that implements the correcponding operation inside the CPU.

• Instruction operands describe data values manipulated by the instruction.

• In this course we will see parts of Intel x86 microarchitecture and its instruction set.