4.2 Hardware Flashcards
What is the CPU?
It is a central procession unit and controls the manipulation of data. It uses data to perform operations. It includes:
- ALU
- CU
- Registers
What are CPU cores?
A core is a set of CU, ALU, and registers. Some CPUs have multiple cores, which means they can process instructions much more quickly.
What is done by the MDR?
It stores the current data needed to carry out instructions.
What is the ALU?
It is the arithmetic logic unit, where mathematical and logical calculations are done.
What is the CU?
It is the Control Unit, which controls the activities done by the CPU
What are Registers?
They are quick, small stores of data within the CPU.
What is the Von Neumann Architecture?
It contains three major characteristics:
- The Main Memory
- Stores Binary Values
- The CPU
- Inputs and Outputs
What is the Fetch-Decode-Execute Cycle?
Fetch:
- The Address of the next instruction is copied from the PC into the MAR
- The PC is incremented by 1
Decode:
- The CU obtains the address of the current instruction from the MAR via the RAM
- The RAM returns the data to the MDR via the data bus
Execute:
- The data from the MDR is copied into the CIR and decoded by the ALU which results are stored in the ACC
What are the 5 Registers?
- Memory Data Register
- Memory Address Register
- Program Counter
- Current Instruction Register
- Accumulator
What is done by the MAR?
The MAR stores the address of the current data that the processor requires.
What affects a CPU’s Speed?
- The number of cores
- The Cache Size
- The Clock Speed
What is done by the PC?
The Program Counter stores the address of the next instruction, and it increments once the address is copied into the MAR.
What is done by the AC?
The accumulator stores mathematical and logic results being transferred from or to the memory unit.
What is done by the CIR?
The Current Instruction Register contains the current instruction which is being carried out.
Why do computers need a clock?
The clock provides timing signals to synchronize the circuits. CPUs are designed to operate at their respective clock speeds, the faster the clock speed the faster the CPU.
The faster the clock speed, the faster the fetch-execute-decode cycle.