1.1 System Architecture Flashcards
Don't fail computing
CPU
The Central Processing Unit: The “brain” of the computer.
Control Unit
Part of the CPU that manages the functions of all other parts of the CPU.`
Decoder
The part of the CU which decodes the binary instructions fetched from memory.
RAM
The main volatile memory into which programs are loaded from the hard drive.
What is the Memory Address Register
Small fast memory used to store the RAM address of the next instruction.
Memory Data Register
Small fast memory used to store the information collected from the RAM before processing.
Program counter
Keeps track of the current instruction number of the program.
Accumulator
Small, fast memory, used to keep track of the data currently being processed.
Arithmetic Logic Unit
Does the basic mathematics and comparisons during processing.
Bus
A physical connection between two elements of a computer system that allows the transfer of data.
Cache
Incredibly fast, but very expensive volatile memory using in the CPU.
Bridge (North/South)
Junctions on a motherboard where the bus connections are controlled and routed. North bridge deals with core functions, whilst the South bridge deals with the peripherals, input and output
devices and Secondary Storage.
Von Neumann
Architecture
The method used by all modern computers to allow the programming of a machine to be changed depending on the required function.
Fetch / Decode /
Execute Cycle
Basis of the von Neumann architecture – the repeated process where instructions are fetched from RAM, decoded into tasks and data, then carried out.
Clock Speed
The number of FDE cycles that a CPU can carry out per second. Measured in Ghz. (1 Ghz = 109 cycles per second or 1,000,000,000hz)
Cores
Some processors have multiple CPUs which can work in parallel, sequentially or can
multitask. Dual and Quad cores are common in modern PCs.
Multi Core Processing
Some processors have multiple CPU cores on one chip. They all have their own Level 1 cache, but share Level 2 cache, allowing them to collaborate quickly on large tasks.
Machine Code
A program, stored in binary, that the CPU undertakes the FDE cycle on. All programs must be in machine code to work.
Instruction
A single line of machine code, containing the command and data location on which it is to be executed. Stored in binary.
Opcode
The first part of the instruction, is the command.
Operand
The second part of the instruction is the data on which to carry out the command. This may be actual data stored in binary form, or a memory location reference of where to find the data.
