Central processing unit
1)Fetch instruction from RAM
2) Copy memory address from the PC to the MAR
Fetch
3) Copy the instruction stored in the MAR to the MDR
4) Increment the PC ready for next cycle
The instruction in the MDR is decoded by the CU.
Decode Carries out instructions using
The CU may then prepare for the next step. fetch-decode-execute cycle
- Loading data from memory
- Write data to memory
- Do a calculation or logic The instruction is performed.
Execute
operation and hold it in the ACC Examples include:
takes input
- Change the address in the PC
Does this via a
computer program
processes data What is
1)Fetch instruction from RAM
2) Copy memory address from the PC to the MAR
Fetch
3) Copy the instruction stored in the MAR to the MDR
4) Increment the PC ready for next cycle
The instruction in the MDR is decoded by the CU.
Decode Carries out instructions using
The CU may then prepare for the next step. fetch-decode-execute cycle
- Loading data from memory
- Write data to memory
- Do a calculation or logic The instruction is performed.
Execute
operation and hold it in the ACC Examples include:
takes input
- Change the address in the PC
Does this via a
computer program
processes data What is
