2.1.3 Reading From Memory

  • 4 Simple Steps to read from Memory
    • 1. Place address of value you want to read on bus
    • 2. Assert the processor’s RD (read) pin
    • 3. Wait one clock cycle for the memory chips to respond
    • 4. Copy the data that has now appeared on the bus
  • Caches on the CPU
    • Used to store most recently used instructions
    • This is done because often the CPU is the true bottle neck to most processes
    • There are levels of cache the lower number=faster=closer to the actual CPU
    • Level 1 is directly on the CPU
    • Level 2 is connected to the CPU by a high speed memory bus
    • These are static RAM (SRAM) which is more expensive and faster than traditional RAM (DRAM)

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