Experiment $1.$ Introduction

In this experiment, you are expected to create a project, compile and simulate it in MPLAB for

PIC$18$F$1220$ Microcontroller. You need to use the same process in all future labs so it is important to

gain a solid understanding of the process and MPLAB.

Step I. Create a Project

$1)$ Start MPLAB

$2)$ Select menu $$File$>$New Project$$; in the pop up window :

$*$ Select Categories "Microchip Embedded" and Projects "Standalone Project", Click $$Next$$

$*$ Select $$Advanced $8-$bit MCUs$$ from Family list and "PIC$18$F$1220."$ from Device list, Click

$$Next$$

$*$ Click $$Next$$

$*$ Select $$Simulator$$ from the Tools Menu, Click $$Next$$

$*$ Select $$mpasm$($v$5\mathrm{.}82)[$C:$\backslash$P$...$ from the Compile Toolchains, Click $$Next$$

$*$ Enter Project Name, Location and folder, check $$Set as main project$,$ click $$Finish$$

Note: It is recommended that you create a new project directory for each new lab experiment to

avoid the most common problem of including old files in new projects.

Step II$.$ Add a Source File

$1)$ Once project is created, new window pops up$,$ on the upper left sub$-$window right$-$click on $$Source

Files$$ under your project name and select $$New $>$ AssemblyFile.asm$.$

Note: If $$AssemblyFile$.$asm$$ is not found then click on $$Other$,$ in the pop up window, click on

$$assembler$$ under categories and then select $$AssemblyFile$.$asm$$ under file types. $2)$ Enter a "File Name" of your choice. main.asm is always a good choice, but you can choose

something more descriptive if you like. Don't enter anything in the Folder: area. You should see a

full path under "Created File:" which should end with $"\backslash$main$.$asm", Click "Finish"

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Note: On the upper$-$middle$/$right side of the window should be a tab labeled "main.asm" This is

where you'll enter your program's source code.

$3)$ Copy the following code into the main.asm file created in the last step. Save your using menu

$$File$>$Save".

Note: All instruction must be indented. Labels and #define must start on column $1.$ You can indent

entire sections of text by selecting the text and hitting Tab key. $4)$ Enable Absolute Addressing

$*$ Right click on the project name and select $$Properties$$

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$*$ Click on $$mpasm $($Global Options$)$

$*$ Click on $$Unlock$$ if not grayed out

$*$ Click the checkbox for "Build in absolute mode"

$*$ Click $$OK$$

Step III. Assembling a Project

$1)$ Select menu $$Production$>$Build Main Project$$ to assemble the code.

Notes:

$*$All instruction must be indented. Labels and #define must start on column $1.$ You can indent entire

sections of text by selecting the text and hitting Tab key.

$*$ Select $$Absolute$$ if prompted with $$Absolute or Relocatable$$ code dialog box.

$*$ The lower$-$right window should have a tab labeled "Output $-$ Lab$1($Build$,$ Load$)"$ and the bottom of

that window should include the messages "BUILD SUCCESSFUL" and "Loading Complete." Any

messages in red indicate an error and messages in blue are warning. Both have to be investigated

and corrected before a successful assembly.

$2)$ Disassembly listing can be generated by selecting menu item

$$Window$>$Debugging$>$Output$>$Disassembly Listing File

Note: This step is only required for the report. If the menu is grayed out $($not available$)$ then rightclick on the project name and select properties. In the property window, select $$Loading$,$ check

$$Load symbols...$$ and Click on $$Apply$.$ After the change, you need to redo step $1$ to generate the

disassembled listing.

Step IV$.$ Initializing Simulator and Debugger

Use the simulation feature of MPLAB to test the functionality of your Project by following the steps

shown:

$1)$ In your source code listing, click on the line number next to the code line that says

$"$CLRF PORTA ; Initialize PORTA"

The entire line should turn red. This indicates that you've created a breakpoint at that line. Each time

the simulator is about to execute a line with a breakpoint, the simulator will pause and return control

to you.

$2)$ Select menu "Debug$>$New Watch..." and under "Enter or Select Watch Expression" enter PORTA

and click OK $($remember that names like "PORTA" are case$-$sensitive: "PORTA" is different from "PortA"$).$ Repeat this step for $$PORTB$$ and $$WREG$.$

$3)$ Select menu $$Window$>$Simulator$>$Stimulus" You'll see a new tab labeled "Stimulus." Click on the

area beneath "Pin" and select RA$0($which specifies bit $0$ of PORTA$).$ Click on the box under Action

and select "Toggle."

Note: Toggle means invert the value from $0$ to $1$ and from $1$ to $0.$

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$4)$ Select $$Debug$>$Debug Main Project." Your main dialog box should now say something like:

i$)$ Launching

ii$)$ Initializing simulator

iii$)$ User program running

iv$)$ User program stopped

v$)$ Breakpoint hit at line $21$ in file $...$

Step V$.$ Simulation and Debugging

$1)$ In addition to Special Function Registers, you can watch General Function Registers such as location

$0$x$80.$