What is the purpose of the CPU?
To process data and instructions by constantly repeating the FDE cycle
What are the steps of the FDE cycle?
Fetch - next instruction and any data involved fetched from main memory (RAM) and brought back to CPU
Decode - understands the instruction
Execute - the instruction is executed (processed/carried out)
The process/cycle is then repeated
What is the function of the control unit?
to direct/coordinate the CPU’s operation such as the timing of other CPU parts
receives signals from the system clock and sends timing signals and control signals to other CPU parts such as RAM and ALU
to decode and execute instructions
What is the purpose of the ALU?
to carry out arithmetic calculations and logic operations
What is the purpose of the PC?
to hold the address of the next instruction to be executed
incremented by 1 as soon as that instruction has been fetched
What is the purpose of the ACC?
to temporarily store arithmetic and logic results from the ALU
What is a register?
a temporary storage place for one instruction or address
What is the purpose of the MAR?
To copy, from the PC, and hold the address of where the instruction or data is to be fetched from or stored in memory (RAM)
What is the purpose of the MDR?
To fetch the instruction at the address in MAR from memory (RAM) and to hold it
the CU will decode that instruction and decide of any data needs to be fetched
if so, the MAR holds the address of the data
the data is fetched and copied to MDR
will also hold any data to be written to memory
What are the key features of Von Neumann architecture?
program instructions and data the programs are using are both stored in the same memory
CPU accesses both instructions and data from the same RAM