Fetch, Execute Cycle & Registers Used

- Instructions are fetched from the main memory
- Intructions are then decoded
- Instructions are then executed

Registers
Program Counter (PC) - Holds the address of the next instruction to be executed
Current Information Register (CIR) - Holds the current instruction while it's decoded and executed
Memory Address Register (MAR) - Holds the address of the memory location being accessed
Memory Buffer Register (MBR) - Holds data being transferred to or from the memory that is held in the MAR
Accumulator (ACC) - Holds the result of the current calculations