FAQ – Fetch Execute Cycle

Simple description, referring to the appropriate buses and control lines, of the steps in the fetch-execute cycle

I have covered this in some detail elsewhere in the blog, but I thought you might want it again.

  1. Processor sets up address bus with correct address
  2. Processor activates read line on control bus
  3. Instruction from memory location is placed on to data bus and transferred to processor’s register
  4. Instruction is decoded and executed

[kml_flashembed movie="http://www.youtube.com/v/aIca1rI4JyQ" width="425" height="344" allowfullscreen="true" fvars="fs=1" /]

Memory Write Operation

  1. Processor sets up address bus with correct address
  2. Processor sets up data bus with data to be written
  3. Processor activates write line on the control bus
  4. Data is placed in the correct memory location

[kml_flashembed movie="https://www.youtube.com/v/xgBeiLNKQ78" width="425" height="344" allowfullscreen="true" fvars="fs=1" /]

Here is the file that I used in the videos.