CPU- The brain of the computer
→ Responsible for processing all the instructions sent from computer programs and actions
are performed in the CPU.
- The code is executed here
- arithmetic , logical, input/output operations.
How does a CPU work? (Von Neuman model)
→ Starting at the PC when we turn on the computer, the data of the program goes into the
RAM and all the instructions for that particular program are stored there.
→ in RAM they are organized into addresses (holds binary data).
- The program counter repetitively goes through all the addresses in RAM and
executes the instructions.
- The program counter sends an address to the MAR (it is a small piece of memory
holding data in a small amount/ very fast)
- MAR sends data through the address BUS and the RAM sends the piece of data
through the Data BUS to the MDR which sends it to the CU (through the Data bus)
then, it is sent to decode data which is then read by the ALU.
- ALU executes the actions- outputted to the monitor/ somewhere in the computer/
somewhere in the RAM.
The process:
Fetch- Decode- Execute cycle- machine instruction cycle
● Program counter
● MAR sends an address to the RAM to be accessed.
● RAM- holds current program data in the form of an address and data.
● MDR- receives that data from the RAM which is sent to the CU where it is decoded
and then sent to the ALU which executes the program
1. FDE is orchestrated by the CU.
2. Cores refer to the number of ALUs in the processor.
3. Processor speed is the number of FDE cycles per second.
Primary memory (RAM):
- Random access memory - short term memory
- It is volatile- data is lost when computer is turned off
- Non- persistent storage
Primary memory (ROM):
- Read only memory