Little Man Computer - Execution Cycle

Execution Cycle

See also: Instruction cycle

To execute a program, the little man performs these steps:

  1. check the Program Counter for the mailbox number that contains a program instruction
  2. fetch the instruction from the mailbox with that number
  3. increment the Program Counter (so that it contains the mailbox number of the next instruction)
  4. decode the instruction (includes finding the mailbox number for the data it will work on)
  5. fetch the data from the mailbox with the number found in the previous step
  6. execute the instruction
  7. store the new data in the mailbox from which the old data was retrieved
  8. repeat the cycle or halt

Read more about this topic:  Little Man Computer

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