Käskyvalikoima

Käskyvalikoima, also known as command set or instruction set, refers to the collection of commands or instructions that a computer's processor can execute. It defines the native language of a computer's central processing unit (CPU) and is crucial for the operation of software applications. Each command in a käskyvalikoima typically performs a specific operation, such as arithmetic calculations, data movement, or control flow management.

The käskyvalikoima is designed by the CPU's architect and is implemented in the CPU's microarchitecture. It includes a set of registers, which are small storage locations within the CPU, and a set of addressing modes, which determine how operands are accessed. The käskyvalikoima also specifies the format of instructions, including the opcode (operation code) and operands.

There are two main types of käskyvalikoima: CISC (Complex Instruction Set Computing) and RISC (Reduced Instruction Set Computing). CISC architectures have a large number of complex instructions, which can perform multiple operations in a single command. RISC architectures, on the other hand, have a smaller number of simpler instructions, which are executed in a single clock cycle.

The käskyvalikoima is a fundamental aspect of computer architecture and plays a significant role in determining a computer's performance and efficiency. It is also a critical factor in the development of software, as it defines the instructions that can be used to write programs.