lesson
Instructions are processed in a sequence
1 · Learn
A simplified processor cycle fetches an instruction from memory, decodes what operation it represents and executes it. Data and instructions are represented digitally, and the program determines what operations are requested.
This model helps explain sequence, but real processors have additional complexity. A processor does not understand the human purpose of a program; it follows the supported instructions and current data.
2 · Worked example
In a paper machine, 'load 3; add 4; output' produces 7. Changing the order can change what is stored or displayed.
3 · Your turn
In the model, what is the difference between fetching and executing an instruction?
Check your answer
Fetching obtains the instruction from memory; executing carries out its specified operation.
4 · Apply your learning
Trace a short paper instruction set and record the working value after every instruction.
Adult guidance and safety
Use an approved private programming or authoring environment and fictional data. Do not install unknown software or enter personal credentials for these exercises. Trace first, then run and test where a suitable tool is available; these text examples do not themselves provide an executable assessment environment.
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