System Architecture & Memory

System Architecture & Memory

1. The Processor is the 'brains of a Computer System', it processes data, caries out instructions and have a clock speed which is measured in Hertz {Hz}. Typical processor speeds span across MHz and GHz. One GHz executes one billion instructions per second.

   • SPEED - Typical processor speeds span across MHz and GHz. One GHz executes one billion instructions per second.
   • CORES - Ever processor has a 'core' in which instructions are executed, however processors can be multi-core: dual core, quad core, 8 core. Each core executes instructions independently. Dual cores may execute up to twice as many instructions per second.
   • CACHE SIZE - Processors have 'Cache', it's very fast and usually a very small amount of memory on a processor chip. It acts as an intermediary between the processor and the Main Memory. The cache holds commonly used instructions as programs are executing.

2. An embedded system is a computer system made up of firmware. They're usually for specialised tasks and don't usually contain an operating system.

3. Registers keep short term memory. The MAR, memory address register, tells you the address of the instruction. The MDR, memory data register, contains the copy of designated memory locations specified by the memory address register. The Program Counter stores the next address. The Accumulator stores the current value.

4. Types of memory:

   • RAM - Random Access Memory - A volatile form of storage.
   • ROM - Read Only Memory - A non volatile form of storage.
   • Hard Disk - A Non volatile Storage
   • DRAM - Dynamic Random Access Memory - A memory chip that depends upon an applied voltage to keep the stored data.
   • SRAM - Static Random Access Memory - A type of memory chip which is faster and requires less power than dynamic memory.