Processor Components Flashcards
(54 cards)
What is another name for the processor?
CPU (Control Processing Unit)
What does the CPU contain?
Components that allow it to execute instructions
What components does the CPU contain?
Control Bus unit
Buses
Arithmetic Logic Unit
Registers
What is the control Unit responsible for?
For the flow of data between components, it will decode an instruction into several sequential steps, in order to determine how an instruction should be executed.
What is a bus?
A set of parallel lines connecting two or more components in a computer system
What is the processor connected to?
The processor is connected to external components by buses. Buses will connect the CPU to RAM (Main Memory).
When is the address bus used?
The address bus is used when data is to be written or read from a memory location, specifically the address is sent down the address bus.
When is the data bus used?
The data bus is used when the data transmitted to an address has to be performed, meaning it acts as a carry (transport) for information.
When is the control bus used?
When synchronisation and control is provided in the form of signals.
What are data and control buses?
Data and control buses are bidirectional buses meaning they transmit data in both directions between the CPU and a component.
What is the address bus?
It is a single directional bus.
What are the three buses collectively known as?
The system bus
What does it mean for a bus to act as a shared transmission medium?
It means only one bus can be used at any one time
What is the purpose of the CPU?
To provide command, timing and status information
What are the types of status information?
Bus request - Indicates a component is requiring access to the data bus
Bus Grant - The CPU has granted access to the data bus
Memory Read - Data is transferred from a memory location to the data bus
Memory Write - Data is transferred from the data bus to be overwritten to a memory location
Bus Busy - Indicates the data bus is currently busy
Clock - Synchronises operations
Interrupt Request - States that a component is requiring access to the CPU
What is memory divided into?
Memory is divided into units called words.
What is a word?
A word is a fixed sized of digits of bits, this is all treated by the processor as a single unit.
What does each word in memory have?
It has its own location, so the number associated with this word is used as an operand when transmitting data to the processor.
Extra Information*
An operand is part of the binary address of a piece of data or instruction used to give command to what will be done with the opcode. Operand is the first 8 bits of a 10 bit address and the opcode is the piece of data to be worked on, the last two bits in the 10 bit binary address.
How is the address of the word used as an operand?
The instruction which is executed (operand) is stored in that specific location (the location of the word) on the data bus.
What is the ALU?
The arithmetic logic unit, which is used for performing arithmetic operations and logical operations.
What are registers?
Registers act as a fast operating memory location as they are quicker to access than main memory, the registers will temporarily store the results carried out in the ALU.
What will most computers do?
Most computers will make use of a single register called the accumulator.
What is another word for a dedicated register?
Special purpose register.