The Fetch Execute Cycle

what is the 1st process of the **fetch execute cycle**?

1. an instruction is fetched form main memory (ROM or RAM) at the location held by the **program counter** register

what is the 2nd process of the **fetch execute cycle**?

2. the value of the **program counter** is incremented so that it points to the next instruction to be processed

what is the 3rd process of the **fetch execute cycle**?

3. The fetched instruction is decoded by the **Control Unit** in the **CPU**

what is the 4th process of the **fetch execute cycle**?

4. The **CPU** executes the instruction by performing an appropriate operation, for example the **ALU** might perform a calculation or data might be loaded from memory

what is the 5th process of the **fetch execute cycle**?

5. The cycle repeats until a HALT instruction is retrieved

what is an **opcode**?

opcodes are the first part of the instruction and they determine what operation the CPU should perform

what is an **operand**?

operands are the second part of the instruction and they provide the values needed for the operation, for example they might represent a memory location for a "Save data" operation, or they may represent a number to include in an addition operation.