Information and Communication Technology

2.1.8 Execution steps

The Central processing unit performs the following three steps repeatedly while processing data:

• Fetching an instruction to the instruction register.
• Instruction decoding to determine the operation to be performed and the storage addres s of data to be used in the operation.
• Instruction execution to perform the specified operation and place the results in the accumulator.

The sequence of steps that the CPU executes is called the instruction cycle. The data path through which data are transmitted between the various units in the CPU is called the data bus .

The overall plan and design of various components of a computer system is referred to as the computer architecture.