Computer Instructions

The length of an instruction depends on how many instructions are supported in total (more instructions = greater length).

---

ISA also indicates the:

• Number of operands that an instruction can include.
• Length in bits of the opcode and of the operands.
• Types of operations (e.g., addition, multiplication.)
• Location/source of the data (inside a CPU register or in RAM.)
• Destination of the data (a register or RAM.)
• Types of operands (e.g., number, address, address of address, etc.)
• The storage order of the bits/bytes (left-to-right or right-to-left.)

We will expand on those on the next slides.