2
Records
Procedure 4 Debugging the program (Simulator)
Procedure #
Function
Comments
PC = 0x4
4.2
Set PC at Cursor
W = 0xff; current value in WREG is FF
Program memory window:
The program counter is set to the 00004 address in memory
PC changes from previous address (0x4) to the current address (0xC)
Program memory window:
4.3
Run to Cursor
The program counter is set to the 0000C address in memory
Run program to the line which is selected. All instructions between
the start and end points will be executed
Open watches window (WindowDebuggingWatches)
With the watches window you can monitor selected file registers, and
variables. This window will show the Name, Type, Address and Value
of the selected variable. You can also change the value of certain
variables (for example, WREG)
4.4
New Watch
4.5
Set Breakpoint
After clicking the play button, the program will only run up to the
break point and stop. The new PC location will be at the address of
the instruction where the breakpoint is located
4.6
Reset
The PC moves back to the start of the program which is location 0 in
memory.
4.7
Finish Debugger
Session
This terminates the debugging session; the user can no longer run the
program and check the states of the various variables and file
registers as they change.
4.8
Run with Pre-set
Breakpoint
The breakpoint is still set. The PC stopped at the address location of
this instruction (0x14) and all the previous instructions were executed.
Step Into
The PC moves to the next instruction (call delay_blink). After stepping
into again, the PC moves into the subroutine called by the previous
instruction (0x76 in memory). This was done despite the breakpoint
still being in place.
Step Over
The main difference between step into and step over is that when the
PC arrives at a call for a subroutine, ‘Step Over’ will execute the
subroutine and automatically move to the next line after the call.
Conversely, ‘Step Into’ will allow the user to manually step through
each instruction in the subroutine before returning to the line after
the call.
4.9
4.10
3
4.11
Step Out
Once the PC is in a subroutine, rather than manually stepping through
each instruction, ‘Step Out’ will automatically run each instruction in
the subroutine then return to the line after the call.
Procedure 5 Going through window tabs
Item Name
Comments
Dashboard
Window located in the bottom left of the screen. Contains information about
hardware such as device information (PIC18F87J11), configuration settings for the
hardware, compiler toolchain, total memory, simulation settings, and Debugging
resources.
Navigator
The second tab in this corner contains a list of all the subroutines in the program. You
can click on these to jump to them in the code.
Variables
Contains the same variables and file registers that are listed in the watches window. It
also shows the same information about each watch (Name, Type, Address, and
Value). The difference is that this window provides an option to show only variables
used near PC location.
Watches
A custom list of variables, file registers, locations in memory and subroutines that can
be monitored during the debugging process in terms of location, and value.
Breakpoints
Shows a list of the breakpoints and their location. From this window you can create
different types of breakpoints such as: line, data, address, and function.
IO View
List of various peripherals associated with the microcontroller. The second window
displays a list of the associated peripherals corresponding to the selected device along
with their address, value and addressable bits. Some examples include: A/D
converter, Port A-J, Timer 1-4. If PORTD is selected, the second window will show the
address, value and bits associated with LATD, PORTD and TRISD.
Program Memory
This window displays the Address, Opcode, Label, and assembly code associated with
each line in the program. This is useful for observing which instruction the PC is on.
Variables are translated into their corresponding location in memory.
File Registers
This window displays an array of each location in memory and the values. By hovering
over the boxes with the cursor, the corresponding file register and location will be
shown.
SFRs
This window shows a list of each SFR. The list contains the name, address, hex value,
and binary value within each SFR.
Configuration Bits
This window shows a list of all the configurable bits for the specific microcontroller.
The only one used in this lab is the XINST (extended instruction set) which is
configured as off. In this window the user can manually toggle the values for these
bits in addition to the code.
Hardware Stack
Keeps track of the return address for when the PC goes into a subroutine.
4
Procedure 6 Analysis of the program
Purpose of The Program
This program causes LEDs D8-D1 to turn on sequentially and then turn off
sequentially in the reverse order.
Specify device type (PIC18F87J11)
Include the instructions for the device.
Disable the extended instruction set.
Assign addresses in memory for variables (delay_count1 and 2)
Set the reset/interrupt vector (start location in memory)
Initialize the pins (RB3-0, RD3-0) as output.
Main Program:
Main Procedures of The
Codes
Turn on each LED, starting from D1 to D8, with a slight pause between each
LED tuning on.
The subroutine delay_blink is used for the delay
The delay works by making the microcontroller count down from FF to 0
twice. It occurs twice because it can’t be initialized to a value greater than
FF. the time it takes for the program to call delay_blink, count down from
FF to 0 twice, and return is the time between each LED turning on/off.
Once all the LEDs are on, the initial procedure occurs in reverse where each
LED is sequentially turned off starting with D8 and with the same delay.
Each LED it turned on by setting (BSF) or by clearing (BCF) the specific bit in
the register. For example:
bsf PORTD, 0; this sets the value of the first bit in PORTD to 1, thus turning
on the corresponding LED (D1).
Procedure 7 Programming the Controller
Procedure #
Task
7.4
Download the Program to the
Microcontroller
Comments
Under project properties, change the
hardware tool from simulation to PICkit3.
Make and program the device.
5
Procedure 8 Debugging the Program (PICkit3)
Procedure #
8.2
Task
Debug the program
Comments
From the dropdown arrow choose ‘Program Device
for Debugging Main Project’
Run and test the program on the selected hardware.
Procedure 9 Reading Memory
Procedure #
Function
Comments
9.1
Read memory to a file
Saved as a hex file.
9.3
Programmer to Go test
Load the program into the PICkit3. From here, the
PICkit3 can be used to program another board with
the code.
Self-check of Completion (to be filled by student)
Item
Completion (Yes/No/NA)
UML activity diagram attached.
Yes
Codes with detailed comments given.
Yes