A Quick Introduction To MPLAB SIM

A Quick Introduction toMPLAB SIMWelcome to this web seminar, “A Quick Introduction to MPLAB SIM.”My name is Darrel Johansen and I’m a manager in the Development Toolsgroup at Microchip.Page 1

What Is MPLAB SIM?OAfree component of MPLAB IDEAn Introduction to Microchip Development Tools2The centerpiece of our tool set is the software MPLAB IntegratedDevelopment Environment, or “IDE.”MPLAB IDE has enjoyed many years of use and evolution, trackingMicrochip’s expanding catalog of microcontrollers and digital signalcontrollers.One of the most popular elements of MPLAB is the software simulator,MPLAB SIM.This component, like the MPLAB IDE is free.Page 2

What Is MPLAB SIM?OAfree component of MPLAB IDEO A software simulator that runs onyour PCAn Introduction to Microchip Development Tools3The simulator runs on your PC to simulate the actions of the various PIC anddsPIC microcontrollers.Page 3

What Is MPLAB SIM?OAfree component of MPLAB IDEO A software simulator that runs onyour PCO A verifier for your softwareAn Introduction to Microchip Development Tools4You can verify your software routines execute as designed Page 4

What Is MPLAB SIM?OAfree component of MPLAB IDEO A software simulator that runs onyour PCO A verifier for your softwareO A debugger to test your codeAn Introduction to Microchip Development Tools5 and debug, test and inspect your code.Page 5

What Is MPLAB SIM?OAfree component of MPLAB IDEO A software simulator that runs onyour PCO A verifier for your softwareO A debugger to test your codeO An optimizer to improve yourapplicationAn Introduction to Microchip Development Tools6MPLAB SIM helps you optimize your application with timing tools, trace tools, and various graphical analyzers.Page 6

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools7We’ll cover the basic elements of the simulator in this web seminar,including: How to configure MPLAB IDE to use MPLAB SIM as the current debugger How to run your code in MPLAB SIM halting at a breakpoint How to single step through your code How to set watchpoints on data variables in your code How to run and halt your code How to use a stimulus to simulate external inputs to your hardware How to use the DEBUG variable to make conditional code executionwhile debugging How to insert fprintf statements in your code to monitor the executingroutines How to measure the execution time of your code, and How to record code as it executes, capturing its history in a buffer to bereviewed.Page 7

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools8Page 8

Starting MPLAB SIMMPLAB DesktopAn Introduction to Microchip Development Tools9You should already be familiar with MPLAB IDE before going through thisseminar. You might want to watch the “Introduction to MPLAB” seminar first.The MPLAB IDE desktop has all the standard Windows features: menus, toolbars with icons, and a status bar at the bottom.Page 9

Starting MPLAB SIMDebugger Select ToolAn Introduction to Microchip Development Tools10To select the simulator, select the Debugger pull down menu, and scroll to“Select Tool” Page 10

Starting MPLAB SIMDebugger Select ToolAn Introduction to Microchip Development Tools11A sub menu pops up Page 11

Starting MPLAB SIMDebugger Select Tool MPLAB SIMAn Introduction to Microchip Development Tools12Scroll down to select MPLAB SIM.Page 12

Starting MPLAB SIMProjectsAn Introduction to Microchip Development Tools13Now the status bar shows MPLAB SIM as the current debugging tool.-- MPLAB deals with applications as “projects.” -Projects are the source files that are used to build the application along withcompilers, assemblers and linkers to “build” the firmware for the application.In this project are three files, “main.c.” “delay.c,” and an assembly file,“int devices.s.”All will be compiled using the MPLAB C compiler and its tool suite for thedsPIC family of digital signal controllers, but this process is the same for theother families of Microchip microprocessors.For more information on setting up a project, see the “Introduction toMPLAB” seminar referenced earlier.Page 13

Starting MPLAB SIMBuild ProjectAn Introduction to Microchip Development Tools14When all the source code is correctly written and the project configuredproperly, click the build icon on the toolbar to compile the files.Page 14

Starting MPLAB SIMBuild ProjectAn Introduction to Microchip Development Tools15If the project builds with no errors, the output window will show “buildsucceeded.”Page 15

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools16Page 16

BreakpointSet BreakpointAn Introduction to Microchip Development Tools17Open a source file for editing or debugging by double clicking on the filename in the project window,After a project successfully builds, position the cursor on the desired line,And click the right mouse button to bring up a menu to set a breakpoint.Page 17

BreakpointAn Introduction to Microchip Development Tools18In the source file the breakpoint is shown by the red symbol with the letter“B”Page 18

Run to BreakpointAn Introduction to Microchip Development Tools19Pressing the “Run” icon, starts the simulation, stopping at the breakpoint.The green arrow on top of the red “B” shows the current program counterlocation at the breakpoint set in the function “main.”Page 19

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools20Page 20

Single StepAn Introduction to Microchip Development Tools21Pressing the “step” icon, single steps one line in the code.Page 21

Step AgainAn Introduction to Microchip Development Tools22Page 22

Step AgainAn Introduction to Microchip Development Tools23Page 23

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools24Page 24

WatchpointsView WatchAn Introduction to Microchip Development Tools25Watch windows inspect variables in your code. Select the Watch windowfrom the View menu.Page 25

WatchpointsSelect Variables to WatchAn Introduction to Microchip Development Tools26Use the right pull down list to see symbols, select the variables to watch Page 26

WatchpointsAdd Variables to Watch WindowAn Introduction to Microchip Development Tools27 then press the Add Symbol button to enter them in the watch window list.Now when the program is halted or stepped, the variables will show changedvalues in red.Page 27

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools28Page 28

RunAn Introduction to Microchip Development Tools29Pressing the “run” icon lets the processor continue running the code from thecurrent breakpoint.The status bar at the bottom disappears and is replaced by a “running”progress bar.Page 29

RunAn Introduction to Microchip Development Tools30Page 30

RunAn Introduction to Microchip Development Tools31Page 31

RunAn Introduction to Microchip Development Tools32Page 32

RunAn Introduction to Microchip Development Tools33Page 33

RunAn Introduction to Microchip Development Tools34Page 34

RunAn Introduction to Microchip Development Tools35Page 35

RunAn Introduction to Microchip Development Tools36Page 36

RunAn Introduction to Microchip Development Tools37Page 37

RunAn Introduction to Microchip Development Tools38Page 38

HaltAn Introduction to Microchip Development Tools39Selecting the “Halt” icon stops program execution at the current programcounter location, just as if it encountered a breakpoint at that instruction inthe code.Page 39

HaltAn Introduction to Microchip Development Tools40In this code, after pressing single step, the green arrow does not advance.The code is in a “while” loop, waiting for a switch on port pin RD7 to go high.Page 40

Topics Covered inThis Web SeminarOOOOOOOOOOStarting MPLAB SIMRunning to a breakpointSingle steppingSetting watchpointsRunning and haltingUsing a stimulusUsing the DEBUG variableUsing fprintf statements to debugMeasuring routine execution time with thestopwatchTracing code as it executesAn Introduction to Microchip Development Tools41Page 41

StimulusDebugger Stimulus New WorkbookAn Introduction to Microchip Development Tools42The action of the switch on pin RD7 can be simulated with a stimulusfunction.MPLAB SIM can respond to the action of external hardware, such asswitches, with the stimulus functions.The stimulus dialog is accessed from the Debugger pull down, scroll to“Stimulus” and create a “New workbook.”Page 42

StimulusStimulus DialogAn Introduction to Microchip Development Tools43The stimulus workbook has tabs for the various types of stimulus.Page 43

StimulusStimulus DialogAn Introduction to Microchip Development Tools44There are six tabs, offering a options to apply stimulus to the simulator,Page 44

StimulusStimulus DialogAn Introduction to Microchip Development Tools45Regular, repeating waveforms, lists of voltage levels, events from files, andsequences of data values can be injected into registers and applied toexternal pins.Page 45

StimulusAsynchronous StimulusAn Introduction to Microchip Development Tools46The “asynchronous” stimulus tab can be used to simulate the action ofpressing a switch.Page 46

StimulusSet PinAn Introduction to Microchip Development Tools47Click on the PIN/SFR column to select the pin RD7.Page 47

StimulusSet ActionAn Introduction to Microchip Development Tools48In the “Action” column, set the action for the pin to pulse high when pressed.Page 48

StimulusSet TimeAn Introduction to Microchip Development Tools49In the width column, a somewhat arbitrary value of “5” makes the pulse last 5cycles, just ensuring the pulse lasts beyond a single instruction.Page 49

StimulusFire StimulusAn Introduction to Microchip Development Tools50Press the “Fire” button to apply the pulse to the RD7 pin.The output window logs the action.Page 50

StimulusStepAn Introduction to Microchip Development Tools51Press the single step key to go forward,into the Delay routine.Page 51

StimulusDelayAn Introduction to Microchip Development Tools52The next step enters the delay routine.Delay routines such as this are often used to slow things down so that adisplay can be seen by the human eye, for instance.When simulating, which runs at a slower speed than the actual processor,these delays are often not needed.While using the simulator, we just need to know that the delay routine iscalled, but we don’t want to step through thousands of iterations of the delayloop.Page 52