Description

Computer Organization and
Programming
Lab Work 3
Dr. Zulkar Nine mnine@gsu.edu
Lab Work 3 Instructions
• Lab 3(a): Load and build an existing project (3 points)
• Lab 3(b): Debug the Project (3 points)
• Lab 3(c): Math Problems (2 points)
Disclaimer
Attendance!
Lab3(a) Load and Build an existing project
in Microsoft Visual Studio
Lab 3(a) Instructions
• Follow the instructions to build the project.
• Take screenshot/screenshots showing the code, and the output window. The output window must show that the project was built successfully.
• Submit to the iCollege.
Load an existing project
• In this lab, you load an existing project.
• Follow the steps :
• Step 1: Download the project
• Step 2: Load the project into Microsoft Visual Studio
• Step 3: Build the project
Step 1: Download the Project (1)
• Now download a project from the link:
• https://tinyurl.com/lab3codefall21
• Click Direct Download
• Most likely it is downloaded in your ‘Downloads’ folder.

Step 1: Download the project (2)
• Go to the folder where it is downloaded
• Unzip the downloaded file
• Right click on the zip file
• Click Extract All…
Step 1: Download the project (3)
Remove “Lab3_code” from the path.
(keep the forward slash at the end)
Step 1: Download the project (4)
• The path should look like
• Click Extract button
• It will extract the files in a folder named –
Lab3_code
in your current directory.
Step 2: Load the project into Visual Studio (1)
• Open Microsoft Visual Studio
• Click “Open a project or solution”
Step 2: Load the project into Visual Studio (2)
• Browse to the directory where you saved the extracted project “Lab3_code”.
• Go inside the folder “Lab3_code”.
• Select ‘Lab3_code.sln’ file.
• Click Open button at the bottom right corner.
• If you see one : click OK.
• The project will be loaded in you Microsoft Visual Studio.
Step 2: Load the project into Visual Studio (2)
If you see the following error!

Close the Source.asm file by clicking ‘X’
Then follow the next slide
Step 2: Load the project into Visual Studio (3)
• Once the project has been opened, you will see the project name in the Solution Explorer window.
• You should also see an assembly language source file in the project named Source.asm.
• Double-click the file name to open it in the editor.
Step 2: Load the project into Visual Studio (4)
• You should see the source code in the editor window

Step 3: Build the Project (1)
• Select Build Project from the Build menu.
• This will assemble and link your program and create an executable file.
Step 3: Build the Project (2)
• You should see messages like the following in your output window, indicating the build progress:

• You should see the message in the last line:
Lab 3(b) Debug the project code
And record the register and flag contents
• An answer sheet is provided with this lab for Lab 3(b).
• You need to debug the code
• Stop for each instruction and record the register content in the answer sheet.
Then explain the register content.
• Submit your answer sheet to the iCollege.
Debug the Project
• Set a breakpoint first.
• Set a breakpoint on a program statement by clicking the mouse in the vertical gray bar just to the left of the code window.
• A large red dot will mark the breakpoint location.
• In this case, set a breakpoint at Line 10.
Debug your code
•Run the Program by selecting Start Debugging from the Debug menu.
Debug the Project
• You should be able to see the register window :

Debug the project
• Turn on the EFLAGS in the register window.
• Right click on the register window
• Then check the flag
Debug the Project
• You must be inside debug mode:
• If you are not in debug mode : Go to Debug -> Start debugging
• If you don’t see the register window: Go to : Debug ->Windows->registers.

Debug your code
• Now the red dot (breakpoint) has a yellow pointer inside of it now.
• That means code execution halts at line 10 now.
Debug the Project
• To execute line 10, Select ‘Step over’ from debug menu
• You can also use shortcut :
Fn+F10
• Now the yellow pointer moved to line 11. That means line 10 is executed.
• Check the EAX register content.
mov Instruction
• mov instruction has two inputs – first one is destination and second one is source.
• mov destination, source
• mov instruction copy the source content to the destination.
• It is more like assignment operation in high level language.
• In the Code, Line 10
• Mov eax, 12345678h
• Here 12345678 is a hexadecimal number. Radix ‘h’ after the number indicates that it is a hex.
• This can be converted to 32-bit binary number. (Try convert it to binary) • Mov instruction stores that value to EAX register that is also 32-bit register.
• After executing line 10, you can see the content change in EAX register.
mov Instruction

Eax contains 12345678
(all the register values are in hexadecimal)

Debug : Line 11
• To execute line 11, Select ‘Step over’ from debug menu
• You can also use shortcut : Fn+F10
• Mov ax, 1122h
• Here 1122 is a hex and it is 16 bit.
• AX is also a 16-bit register.
• After executing the mov instruction,
• Only AX part (lower) of EAX register updated.
• The upper part is unchanged.
Debug: Line 12
• To execute line 12, Select ‘Step over’ from debug menu
• You can also use shortcut : Fn+F10
• Mov bl, al
• Here the content of AL register is moved to the BL register.
• AL register is the lower 8-bit of the EAX register.
• It contains 22 now.
• 22 is a hex
• BL is the lower 8 bit of EBX register
• BL is the destination here
• After executing this line, BL contains 22 as well. However, rest of the EBX register remains unchanged with previous garbage values.
Debug: Line 13
• To execute line 13, Select ‘Step over’ from debug menu
• You can also use shortcut : Fn+F10
• Mov bl, ah
• Here the content of AH register is moved to the BL register.
• AH register is the upper 8-bit of the AX register.
• It contains 11 now.
• 11 is a hex
• BL is the lower 8 bit of EBX register
• BL is the destination here
• After executing this line, BL contains 11 as well. However, rest of the EBX register remains unchanged with previous garbage values.
Add and Sub instruction
• add instruction has two inputs – first one is destination and second one is source.
• add destination, source
• add instruction adds the source content to the destination and store the result in destination.
• For example,
• add al, 12h
• Adds 12 to the content of AL register and store the result in AL register
• It is more like : al = al + 12 in a high level language
• sub instruction is similar to add instruction
• Instead of addition it performs subtraction.
Submission : Lab 3(b)
• Debug the rest of the code one line at a time.
• There is an answer sheet provided with the lab.
• After executing each line record the register value in the answer sheet.
• Then also provide short explanation for the changes.
• Submit the filled-out answer sheet at iCollege.
Processor Clock
A review
Clock
• Each processor has a built-in clock to synchronize the internal operations. • Each CPU operation synchronized by an internal clock pulsing at constant rate.
one cycle
1
0
• A clock is a sequence of 1’s and 0’s
• Clock Cycle: a 0 and 1 produce a clock cycle
• Frequency: The number of cycles happens per second
• Unit : Hz = 1 cycle per second
Clock
• Clock period = time length of a clock cycle

• A CPU has a clock frequency 1 GHz. What is the clock period?
• Clock period = =1𝑛𝑒𝑛𝑜𝑠𝑒𝑐𝑜𝑛𝑑
• Let’s say an instruction, takes 40 clock cycle to execute in your 1 GHz processor. What is the actual time it takes to execute the instruction?
• Clock period = 1 ns, so each cycle takes 1 ns to finish
• 40 clock cycle takes = 40 * 1 ns = 40 ns to finish
• So, the instruction takes 40 ns to execute.
An example
• Suppose a program contains 1 billion instructions to execute on a processor running on 2 GHz. The instructions takes 3 clock cycles to execute. What is the execution time of the program?
• Answer:
• 1 billion instructions each takes 3 clock cycles
• Total clock cycle for the program = 1 billion * 3 cycles = 3∗109cycles.
• Given, Processor Frequency = 2 GHz
• Processor produces 2∗109 cycles in 1 second.
• 2∗109 cycles takes 1 second
• 3∗109 cycles takes second = 1.5 seconds.
Clock per Instruction (CPI)
• Is an effective average.
• It is the average number of clocks required by the instructions in a program.
• In a program 30% instructions takes 4 clock cycles, and the rest of the instructions takes 1 clock cycles.
• CPI = 0.3 * 4 + 0.7 * 1 = 1.9 clocks per instruction.
Million Instructions Per Second
• Step 1: Perform Divide operation between no. of instructions and Execution time.
• Step 2: Perform Divide operation between that variable and 1 million for finding millions of instructions per second.
• For example,
• if a computer completed 2 million instructions in 0.10 seconds
• 2 million/0.10 = 20 million.
• No of MIPS =20 million/1 million
• = 20
Lab 3(c) Some math Problems
Submit the problems

Lab 3(c) : Submission
• Solve the Problems provided in slide 45 and 46.
• You can do your work in a text editor (Microsoft word, open office, etc.) • Or you can do it in a piece of paper, then scan or take a picture of the paper.
• Convert them into pdf and submit in the iCollege.
Dr. Zulkar Nine
Problem 1
• Suppose a program contains 500 million instructions to execute on a processor running on 2.2 GHz. Half of the instructions takes 3 clock cycles to execute, where rest of the instructions take 10 clock cycle. What is the execution time of the program?
Zulkar Nine (email: mnine@gsu.edu)
Problem 2
• A processor is 20 MIPS. If you run a program on that processor and the program takes 30 seconds to finish. How many instructions are there in this program?
Zulkar Nine (email: mnine@gsu.edu)