1.1 Characteristic Of CPU Flashcards
ALU definition
Arithmetic and logic unit used to complete arithmetic and logic operations
Control unit definition
The control unit directs the operation of the cpu
Registers definition
Registers are small memory cells that operate at very high speeds used to store data
Program counter definition
The program counters holds the next instruction to be executed
Accumulator definition
The accumulator stores the result from calculations
Memory Address Register definition
The MDR holds the address of a location that is to be read from or written to
Current Instruction Register
The CIR holds the current instruction being executed divided up into the operand and code
Where is the BIOS
The basic input/output system is stored in non-volatile memory
What is the BIOS
The BIOS tests the hardware in a computer so it is ready and loads the boot loader program
Data bus definition
A data bus is a bi-directional used for transporting data and instructions
Address bus definition
The address bus is used to transmit the memory address
Control bus definition
The control bus is bi-directional bus used to transmit control signals
Assembly code definition
Assembly uses mnemonics to represent instructions. The instruction is divided into the operand and code in the CIR
Pipelining definition
Pipelining is the process of fetch decode execute of three separate instructions simultaneously
Use of pipelining
Used to reduce the amount of the CPU which is kept idle
What is a Reduced Instruction Set Computers (RISC)
there is a small instruction set. Each instruction is approximately one
line of machine code and takes one clock cycle.
What is a Complex Instruction Set Computers (CISC)
In these processors there is a large instruction set. The aim is to try and accomplish tasks
in as few lines of assembly code as possible
RISC Or CISC:
The compiler has to do more work to
translate high level code into machine
code.
RISC
RISC Or CISC:
More RAM is required to store the code.
RISC
RISC Or CISC:
Pipelining is possible since each instruction
takes one clock cycle.
RISC
RISC Or CISC:
Many specialised instructions are made,
even though only a few of them are used.
CISC
RISC Or CISC:
Less RAM is required since code is
shorter.
CISC
RISC Or CISC:
Many specialised instructions are made,
even though only a few of them are used.
CISC
What is a Multi-core CPU
a CPU with multiple independent cores, that can complete instructions
separately which results in higher performance
What is a Graphics Processing Unit (GPU)
A device which work in parallel making it very efficient at completing repetitive tasks
such as image processing and machine learning
What happens in the Fetch Phase
Address from the PC is copied to the MAR. The Instruction held at that address is copied to MDR by the data bus
The PC are increments by 1.
What is the Fetch-Decode-Execute Cycle
The sequence of operations that are completed in order
to execute an instruction.
What happens in the Decode Phase
The control unit works out what the instruction is and sends signals to coordinate the other components.
What happens in the Execute Phase
The instruction is executed, using the ALU if necessary. Then then the cycle starts again
Three factors that affect CPU performance
Clock speed, number of cores and the amount of cache memory.
What are the properties of RISC?
Small instruction set
Each instruction is one line of machine code
Used in everyday devices
What are the properties of CISC?
A large instruction set
Instructions are built into hardware
Used in embedded systems and microprocessors
What are the benefits of RISC processors?
Pipelining is possible since each instruction takes one clock cycle
What are the benefits of CISC processors?
Compilers have to do less work, They require less RAM since instructions are smaller
