1.1.1 Flashcards
Structure and function of the processor
What does the ALU do?
It performs arithmetic and logical operations such as fixed-point and floating-point operations, logical operations (AND, XOR, OR) and shift operations.
What is the function of the control unit?
Manages and co-ordinates activities of C.P.U.
Fetches next instruction, decodes it into sequential steps, manages execution and then stores results into correct memory or registers.
What is the function of a clock?
System clock sends signals to all computer components in order to synchronise computer operations.
What is a register?
A fast memory location in the processor or I/O controller.
What are general purpose registers used for?
Used to store data and instructions as a temporary measure.
What is a dedicated register?
Used by the processor to carry out a specific rule.
What is the function of the accumulator (ACC)?
It is special register used as fast temporary storage by the ALU.
What is the function of the Program counter (PC)?
Holds the memory location of the next instruction to be fetched.
What is the function of the memory address register?
Holds the address of the current instruction being executed.
What is the function of the memory data register?
Holds contents of MAR and associated data.
What is the function of the current instruction register?
Stores the instruction to be decoded and executed.
What is the bus system?
Communication link connecting various parts of a computer.
What is the function of Main memory?
It is where instructions and data processed by the processor are stored.
What is the function of Data Bus?
Transfers data
From processor to memory (write)
From memory to processor (read)
What is the function of Address Bus?
Specifies physical address in main memory; data to be read or written specified by data bus.
What is the function of the control bus?
Manages data processing by sending write and read signals to data bus.
What is the function of an I/O controller?
Input (read) and output (write) signals sent to processor.
How is PC used in functionality of processor?
- Stores address of next instruction
- Controls sequence which instructions are retrieved and executed.
- Incremented after being read
- Altered through jump instruction
How does Clock speed affect processor performance?
- Gives more FDE cycles per second
- More instructions executed per second
- Program executed in shorter time
How does cache memory affect processor performance?
- More space for data/instructions
- RAM need less access
- Faster to access cache then RAM
How does cores affect processor performance?
- Cores are independent processors located on CPU
- Can process instructions increasing amount of instructions processed in a second
- Decreases processing time of programs
Explain Von neumann architecture.
- Data and instructions stored in single memory location
- Data and instructions transmitted via shared data bus
- Used in general purpose computer systems
Explain Harvard stored program computer.
- Data and instructions stored in separate memory locations.
- Instructions are fetched from instruction memory serially
- Data is fetched when needed by an instruction
- Faster as transmission of data and instructions can happen in parallel
- Used in DSP (Digital signal processing) systems
What is pipe-lining?
Allows next instruction to be fetched whilst simultaneously performing logical or arithmetic operations, holding them in a buffer close to processor until the instruction can be performed.
Can be divided into arithmetic and instruction pipeline.
Arithmetic pipeline represents part of an arithmetic operation that can be broken down and overlapped as they are performed.
Instruction pipeline consists of stages where an instruction is moved through a processor.
