9. Internal Components Flashcards
1
Q
Fetch-Execute Cycle
A
The process of how a computer processes information and instructions.
Consists of 3 parts: Fetch, Decode, Execute.
2
Q
Fetch
A
- > Contents of PC get copied onto MAR
- > Address bus is used to transfer this address onto main memory
- > Contents of addressed memory location loaded into the MBR
- > Transfers data through the data bus
- > Increments PC by one
- > Transfers contents of MBR to CIR
3
Q
Decode
A
- > Instruction to be decoded is held in CIR
- > The CU decodes the instruction
- > The instruction is split into opcode and operand
4
Q
Execute
A
If necessary, data is fetched
- > Opcode identifies the type of instruction it is
- > Operand is the data to be acted on.
- > Execute instruction by relevant part of processor
- > Result is stored in the accumulator
- > Status register is updated
5
Q
PC
A
Program Counter
It is a register that indicates where the computer is in its program’s sequence.
6
Q
MAR
A
Memory Address Register
This register holds onto memory location of data that needs to be accessed.
7
Q
Address Bus
A
Unidirectional
Adresses come out of the CPU and into other components.
8
Q
MBR
A
Memory Buffer Register
It acts as a buffer allowing the processor and memory units to act independently without being affected by minor differences in operation. It’s contents will then be copied onto the CIR to be decoded.
