The CPU (Registers (Memory Address Register (Holds the memory address of…
Memory Address Register
Holds the memory address of the instruction or data to be fetched or stored
Memory Data Register
Temporarily stores the data or program instruction that is fetched from memory
Holds the address of the next instruction to be processed
The results of operations can be temporarily stored here
Current Instruction Register
holds the current instruction to be executed
von Neumann Architecture
Stores both data and instructions to be processed
Fetch Decode Execute Cycle
Address of the next instruction is copied from Program Counter to MAR
PC is incremented to point to the next instruction to be fetched
At the same time the memory is copied to the MDR
The Control Unit decodes the instruction that is held in the CIR
The instruction is executed, this might be a calculation. retrieval from memory or jumping to another part of a program
Factors affecting CPU performance
measured in Hertz the clock speed is the number of processes that can happen per second. The faster the clock speed the more processes and therefore better performance
a fast type of memory that is physically located closer to the CPU. Allows for faster processing as a result of increased reading speed.
more cache memory will allow for faster retrieval of data/ instructions therefore faster processing time
Number of Cores
many processors now have multiple cores. This means that multiple processes can happen a the same time therefore faster results
Bottle necks can occur and this advantage is irrelevant when one core is waiting on the output of another.
Computers with a dedicated purpose.
Usually don't require an OS as tasks are simple or repeated e.g. button presses.
Examples might include:
Generally reliable due to simplicity