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

Famous quotes containing the words execution and/or cycle:

    “Some hours seem not to be occasion for any deed, but for resolves to draw breath in. We do not directly go about the execution of the purpose that thrills us, but shut our doors behind us and ramble with prepared mind, as if the half were already done. Our resolution is taking root or hold on the earth then, as seeds first send a shoot downward which is fed by their own albumen, ere they send one upward to the light.”
    —Henry David Thoreau (1817–1862)

    “The Buddha, the Godhead, resides quite as comfortably in the circuits of a digital computer or the gears of a cycle transmission as he does at the top of a mountain or in the petals of a flower.”
    —Robert M. Pirsig (b. 1928)