ECE 3561 - Lecture 1 1
L8:Flowcharting a program
Department of Electrical and Computer EngineeringThe Ohio State University
ECE 2560
Flowcharting
Where does flowcharting come in?Flowcharting symbols and examplesFlowcharting a program
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What is flowcharting
Flowcharting is a method of documenting an algorithm or method for performing a sequence of actions.
Could be something that is not intended for a computer program.
Provides a graphical view of the process or method.
For assembler language can even indicate register and memory usage
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Flowcharting symbols
Straight action (or code sequence)
Enclosed in a box – sequence of code goes in the box.
Example – exchange 2 items A - -> Temp B - -> A Temp - -> B
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Flowcharting symbols
Decision structure
Example dec I jge yes Code for false branch jmp after yes Code for true branch after code that follows structure
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Flowcharting loops
A for loopFor I = 1 to 10 Loop code in loopEnd loop;
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Flowchart for a problem
We considered multiply routine (note: different register numbers used here)
Note symbol for subroutine and enter/return
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Other flowchart symbols
Have seem actions, decision, subprocess, enter/return
A couple of others that are often used
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Flowchart hierarcy
Flowchart can be written such that what is in the action (process) box is a high level statement.
The high level statement can be a program in and of itself
ORA flowchart can be done indicating
assembler instructions and which registers are used.
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