The Software
Construction Process
Computer System Components
Interne
t
Network Interface Devices
(Modem, Network Card)
Input Devices
(Mouse, Keyboard)
Output Devices
(Monitor, Printer)
Communications Bus
Secondary Storage
(Hard Drive,
CD-ROM Drive)
Central Processing
Unit
(Microprocessor)
Primary Storage
(RAM)
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A Software Requirement
Develop a program that finds and prints
all numbers between 1 and 10,000 that
are divisible by both 7 and 3. For each
number found, display the number and
the product of the two quotients.
The Requirement and the Design
S
Set number to 1
Develop a program
that finds and prints
all numbers between
1 and 10,000 that are
divisible by both 7 and 3.
For each number found,
display the number and
the product of the two
quotients.
Number less than
or equal to 10,000
No
Yes
No
Number divisible by 7
Yes
No
Number divisible by 3
Yes
Print number information
Increment number by 1
F
Boards, Tubes, and Patch Cables
Application Program
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Setting Switches
Application Program
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I/O Devices and Operating System
Operating
System
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Application
Program
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Assembly Language, Monitor,
and Keyboard
Operating
System
Assembler
LOOP: LOAD A, R1
LOAD 7, R2
TEST R1, R2
BRZ LOOP
Application
Program
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Compiler (Syntax and Semantics)
Operating
System
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int main (void)
{
int anAnswer;
float aValue;
Assembler
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anAnswer = aValue / 3;
printf(“%d\n”,anAnswer);
return 0;
}
Compiler
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Application
Program
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#include <stdio.h>
Algorithm in C Source Code
aNumber = LOWNUMBER;
while (aNumber <= HIGHNUMBER)
{
firstQuotient = aNumber / FIRSTDIVISOR;
if ( (aNumber % FIRSTDIVISOR) == 0 )
{
secondQuotient = aNumber / SECONDDIVISOR;
if ( (aNumber % SECONDDIVISOR) == 0)
{
theProduct = firstQuotient * secondQuotient;
printf("%d %7.2f %7.2f %8.2f\n",aNumber, firstQuotient,
secondQuotient, theProduct);
} // End if
} // End if
aNumber++; // Increment aNumber by one
Note: This is only a portion of the complete C program
From Requirements to Running Program
Design Fundamentals
Software Requirements
Design Method
Coding Standards
Software Design
Text Editor
C Header Files
program.c (Source Code)
Compiler (and
Preprocessor)
Function Libraries
program.o (Object Code)
Linker
Input/Output Facilities
program.exe (Executable Code)
Operating System
Software Construction Process
Requirements
1
DESIGN
2
8
EDIT and
SAVE
BASELINE
COMPILE
3
A
E
B
D
4
LINK
C
7
5
TEST and
SQA
6
Note: See next slide for meanings of A - E
RUN
Categories of Errors
• A: Compiler errors – doesn’t follow preprocessor or
C syntax
• B: Linker errors – functions declared but not
defined; no main function; function library not found
• C: Run-time errors – segmentation fault; out-ofrange errors; wrong data types
• D: Logic errors – wrong use of control statements;
errors in function arguments; algorithm coded
incorrectly
• E: Design errors – doesn’t follow design or satisfy
requirements; design has flaws
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