Abstract


Important

Data stored is lost when power is off!

Random-Access

  • A random memory location can be accessed instantly without waiting to reach that location, exhibiting complexity. Unlike a hard disk, where we need to move the ‘needle’ to the physical memory location first before we can start accessing the stored data

Memory Element

  • A device which can remember value indefinitely
  • Change value on command from its inputs
  • A basic unit of storage element, able to store 1 Bit
  • 2 Types - Latch & Flip-flops

Physical Address

  • The address that points to a collection of Memory Element
  • Usually one physical address points to 8 memory elements to form one Byte

Memory Frames

SRAM


  • Stands for Static Random Access Memory
  • A type of Main Memory characterised by its fast access speeds, but generally higher cost and lower density (stores less data per unit area)
  • Commonly used to build CPU Cache and Register etc

Important

  • SRAM will hold its data permanently in the presence of power
  • Faster than DRAM

DRAM


  • Stands for Dynamic Random Access Memory
  • The ‘RAM’ that is commonly known to the consumers

Important

DRAM decays in seconds and thus must be periodically refreshed. Thus Slower than SRAM.

Important

DDR SDRAM is the DRAM that is commonly found in our machines, the common size is 8GB and 16GB.

GDDR SDRAM is the DRAM that is commonly found in GPU, supports high volume of data transfer.

References