CPU Structure Flashcards
Name all the registers in the CPU
Memory Address Register (MAR)
Memory Data Register (MDR)
Current Instruction Register (CIR)
Accumulator (ACC)
State the function of the Arithmetic Logic Unit
- Does the arithmetic calculations in the computer
- Makes logical decisions in the computer
Define:
‘Bus’
Collection of wires which allow data/instructions to be communicated
What is the function of the Data bus?
Responsible for moving data between the CPU and main memory
What is the function of the Address bus?
Sends the memory address (CPU -> RAM) of the next instruction to be fetched
What does the Memory Address Register hold?
Memory Address of the next instruction to be decoded and executed
What does the Memory Data Register hold?
Data being sent to or received from RAM
What does the Current Instruction Register hold?
The Memory Address of the current instruction being worked on
Name some advantages to Von Neumann architecture
- Only one data bus so less complex for CU to manage
- One data bus = cheaper
Name some advantages to Harvard architecture
Separation of data and instructions in two buses means that processes can be carried out in parallel
Name some disadvantages to VN architecture
Can only work on one task at a time
Name some disadvantages to Harvard architecture
More expensive as there are more buses.
Contemporary architecture:
Where cache is split into data + instructions and there are two data buses
One data bus goes forwards towards RAM, one data bus comes to the CPU.
