Structure And Function Of The Processor Flashcards
(51 cards)
What is the ALU?
It completes all the arithmetic and logical operations. (Arithmetic and Logic Unit)
What does the arithmetic operations include?
It includes all mathematical operations such as addition and subtraction on fixes or floating point numbers.
What do Logical operations include?
It includes Boolean logic operations such as And, Or, Not, Xor.
What is a Control Unit?
It is the component of the processor which directs the operations of the CPU.
What jobs does the The Control Unit have?
- Controlling and coordinating the activities of the CPU
- Managing the flow of data between the CPU and other devices
- Accepting the next instruction
- Decoding instructions
- Storing the resulting data back in the memory
What are registers?
Registers are small memory cells that operate at a very high speed.
What are registers used for?
They are used to temporarily store data and all arithmetic, logical and shift operations in these registers.
Purpose of a Program counter, PC (register)?
Holds the address of the next instruction to be executed.
Purpose of the accumulator, ACC (register)?
It stores the results from the calculations
Purpose of the Memory Address Register, MAR (register)?
Holds the address of a location that is to be read from or written to.
Purpose of the Memory Data Register, MDR (register)
Temporarily stores data that has been read or written to memory.
Purpose of the Memory Data Register, MDR (register)
Temporarily stores data that has been read or data that needs to be written.
Purpose of the Current Instruction Register, CIR (register)
Holds the current instructions being executed, divided up into operand and opcode.
What are buses?
Buses are a set of parallel wires which connect two or more components inside the CPU.
What are the 3 buses and what are they called collectively?
Data bus, control bus, address bus and collectively they are called the system bus.
Typical bus width?
8, 16, 32, 64 wires wide
What is a data bus?
It is a bi-directional bus, carries the binarys 1’s and 0’s that make up the information being transmitted around the CPU.
What is the address bus?
Carries the memory addresses specify where data is to be sent to or retrieved from.
What is a control bus?
It is a bi-directional bus used to carry control signals to and from every component of the CPU.
The control signal includes:
- Bus request : shows that a device is requesting the use of the data bus
- Bus grant : shows that the CPU has granted access to the data bus
- Memory write : data is written into the addressed location using this bus
- Memory read : data is read from a specific location to be placed onto the data bus
- Interrupt request : shows that a device is requesting access to the CPU
- Clock : used to synchronise operations
What does Assembly language use + example ?
It used mnemonics to represent instructions, for example ADD represents addition.
What is assembly code a simplified way of saying?
Machine code
What does the assembly language do?
The instructions are divided into operand and opcode in the Current Instruction Register. The operand contains the data or the address of the data upon which the operation is to be performed. The opcode specifies the type of instruction to be executed.
What is pipelining?
It is the process of completing the fetch, decode and execute cycles of three separate instructions simultaneously, holding data in a buffer in close proximity to the CPU until it’s required. While one instruction is being executed, another can be decided and another fetched.
