Fetch Execute Decode

3. Fetch

'Fetch' is the first part of the cycle.

The actions are:

• The Program Counter is loaded with the location of the next instruction to be executed.
• This address is then loaded into the Memory address register (MAR) which is connected directly to the address bus. What this means is that the address bus is now pointing to the instruction in RAM
• This instruction is copied from RAM on to the data bus which then allows the Memory Data Register (MDR) to store a copy of it.

Now it is ready for the next phase which is 'decode'.