4938766
Description
Flashcards by Nathan Hall, updated more than 1 year ago
|
Created by Nathan Hall
about 8 years ago
|
|
| Question | Answer |
| CPU | (Central Processing Unit) The main component of a computer, built of billions of transistors, that coordinates it operations by running a continuous fetch-execute cycle |
| Clock Speed | The rate at which full loops of the fetch-execute cycle are complete. Measured in Hertz (Hz) |
| Registers | Temporary memory locations inside the CPU |
| PC | (Program Counter) Keeps track of the memory location of the instruction being executed, increased with every loop of the fetch-execute cycle, to guide to the next location. (Affected by flow control changes) |
| MDR | (Memory Data Register) Stores the data that has been fetched from or stored in memory |
| MAR | (Memory Address Register) Stores the address of the data/instruction that are to be fetched from or sent to |
| CIR | (Current Instruction Register) Stores the most recently fetched instruction, waiting to be decoded and executed |
| ACC | (Accumulator) Stores the results of calculations made by the ALU or data loaded from a memory register |
| General Purpose Registers | Used to temporarily store data being used to speed up transfer times and to reduce bottlenecking |
| Buses | Communication channels through which data can be sent around a computer |
| Data Bus | Carries data between the processor and the memory |
| Address Bus | Carries the address of the memory location being read or written to |
| Control Bus | Sends control signals from the control unit |
| ALU | (Arithmetic Logic Unit) Carries out all the calculations and logical decisions of a processor. Results stored in ACC |
| CU | (Control Unit) Sends out signals to co-ordinate how the processor works. Controls how data moves around the computer Instructions are decoded in the control unit |
| Improving CPU performance | Cache Memory: - Reduces bottlenecking - Shorter distance to travel - Commonly used data = readily available - Bigger Cache = More Expensive = Slower Multiple Cores: - Each core = separate processor and cache - Share same higher level cache - Multiple questions at once |
| Von Neumann Architecture | A computer architecture, focussed on the shared storage for data and programs |
| Von Neumann Bottleneck | Both data and instructions share a common data bus, Instructions can't be fetched as data is sent along the bus Reduced by using cache memory |
| Harvard Architecture | An architecture where data and programs are stored separately with separate busses Tends to be used by RISC processors |
| Parallel Processing | Multiple operations are ran simultaneously to solve a given problem |
| Distributed Computing | Multiple computers over aa network takes in a part of the problem (SETI@home) |
| SIMD | (Single Instruction Multiple Data) Same operation on multiple pieces of data (e.g. GPUs) |
| MIMD | (Multiple Instructions Multiple Data) Different instructions on different pieces of data |
| RISC | (Reduced Instruction Set Computing) The number of instructions available is streamlined, reduced general purpose registers. Instructions should use about the same no. of clock cycles to allow for pipeline (e.g. Only LDA and STA access memory) |
| CISC | (Complex Instruction Set Computing) non-RISC processors |
| RISC VS CISC | RISC = GOOD: - Less heat - Less power Costs lest to produce RISC = BAD: - Harder for compiler (RISC <-> CISC) |
| Input Device | A device that allows data to be inputted into a computer |
| Output Device | A device that allows information to be retrieved from a computer |
| Storage Considerations | - Cost (£ per mB) - Speed (Speed to write and read) - Capacity (i.e. size) - Portability - Durability |
| Optical Storage | A laser looks at the reflection of a disk to locate pits on the surface Normally cheap to distribute and fairly resilient (e.g. CD's and Blu-ray's) |
| Flash Storage | Uses a special type of ROM that can be overwritten, containing no moving parts Has high speeds, consumes less power, but has high costs Limited no. of times each location can be written too (e.g. Flash Drives, SSD) |
| Magnetic Storage | Patterns on magnetised tape used to represent binary sequences High capacity - Low cost (e.g. HDD) |
| Hybrid Drives | Capacity of magnetic drive + Speed of flash storage |
| Virtual Storage | Involves storing data at an external site Advantages: - Large capacity available - Automatically backed up |
| RAM | (Random Access Memory) Programs/data ran by a computer are temporarily stored Each location can be accessed at the same speed (RANDOM) Much quicker transfer speeds Volatile - no power = RAM lost |
| ROM | (Read-Only Memory) Can be read from but not written too Common use = Stores boot-up sequence Non-volatile = retains contents without power |
| Cache Level Speeds |
Want to create your own Flashcards for free with GoConqr? Learn more.