2.2. Instruction Execution

A computer is controlled by a program, which is composed of sequences of instructions. At the assembly language level, each instruction specifies one fundamental operation to be performed by the CPU. Instructions can be classified into six basic categories:

  1. Data movement instructions move data from one location in memory to another, between memory and registers, among registers, or between memory and I/O devices.

  2. Arithmetic instructions perform various mathematical operations, such as the addition of one quantity to another.

  3. Logical instructions perform Boolean operations, such as AND, OR, and EXCLUSIVE OR.

  4. Comparative instructions examine a value, or compare values, as part of setting up decisions for conditional program ...

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