Computer Hardware

Computer Hardware

1. Memory

   • RAM
     • RAM stands for Random Access Memory
     • RAM is volatile
       • This means that anything stored in RAM will be lost if the power is cut
   • ROM
     • This stands for Read Only Memory
       • ROM is non volatile
         • This means that even when the power supply is cut off the memory would be kept

2. CPU

   • CPU stands for central processing unit
     • The purpose of the CPU is to process data
       • Fetch the instruction: The next instruction is fetched from the memory address that is currently stored in the program counter (PC), and stored in the instruction register (IR).
         • Decode the instruction: During this cycle the encoded instruction present in the IR (instruction register) is interpreted by the decoder.
           • Execute the instruction: The control unit of the CPU passes the decoded information to the relevant function units of the CPU to perform the actions required by the instruction such as reading values from registers, passing them to the ALU to perform mathematical or logic functions on them, and writing the result back to a register
   • Clock Speed
     • A CPU's clock speed rate is a measure of how many clock cycles a CPU can perform per second
     • CPU clock speed, or clock rate, is measured in Hertz — generally in gigahertz, or GHz