CS Flashcards
(18 cards)
What does CPU stand for?
Central Processing Unit
What is the purpose of the CPU?
The CPU processes data and instructions by constantly repeating the fetch-decode-execute cycle.
What are the 4 components of the CPU?
Cache, Registers, ALU, CU
Describe the purpose of the CU.
To decode instructions for the CPU to process in the DFE cycle and control data flow.
Describe the purpose of the ALU.
To perform logical and arithmetic operations.
Describe the purpose of the registers.
To store data temporally for one instruction or address.
Describe the purpose of the cache for the CPU.
To store frequently accessed data for the CPU temporarily.
What do the different levels in the CPU cache mean?
The lower the number the faster the data can be accessed but it holds less storage.
Describe the key feature of the Von Neumann Architecture.
Stores both program data and instructions in the same RAM.
How is data transferred between hardware and memory?
Buses
What does the PC register do?
A register that tracks the RAM address of the next instruction to be fetched.
What does the MAR register do?
A register that tracks the RAM address of the instruction that is to be fetched.
What does the MDR register do?
The MDR stores the instruction that has been transferred from RAM to the CPU.
What does the CIR register do?
A register that stores the instruction that has been fetched from RAM, and is about to be decoded or executed.
What does the ACC register do?
Stores the result of an arithmetic or logical calculation.
What are the each steps of the DFE cycle. [7]
The PC holds the instruction of the next address and copied to the MAR register then the PC register is increased by 1 to go to the next memory address after the CPU calculates the current one then the CPU checks the address in RAM which matches the address in MAR then the instruction is transferred to the MDR then the contents of the MDR is copied to the CIR register then the instruction in the CIR is decoded and executed the result is then stored in the accumulator and then the cycle repeats.
What is cache memory?
Cache memory is temporary storage for frequently accessed data by the CPU.
