CodeTimer

Code Timer for PBP

Code Timer by Steve Burrow

  Published on 9-13-2006
   Version: 1.2.3d 

Download: Code Timer for PBP

Timer for PBP code allows for the timing of how long PBP code routines take to execute for the PIC18 series.

Special thanks to Darrel Taylor. It was his code that was the seed for this project. He also provided important answers and help directly. Additionally, it was through careful study of his projects that I was able to learn what I needed to put this together.


Notes : There are two methods of use. One simply times any block of code (or multiple blocks of code). The other uses PIC BASIC Pro's built in DEBUG function to time individual PBP commands.

(Although not tested, it will probably work with PIC16s.)

THIS IS DESIGNED TO SEND THE RESULT OF THE

TIMING TO PRECONFIGURED HARDWARE SERIAL PORT

VIA THE HSEROUT COMMAND.

If this is not desirable, the HSEROUT commands could be replaced by another more appropriate command. Such as SEROUT Pin, Mode,[]. No changes should be made to the code inside the brackets of the HSEROUT commands.

IMPORTANT NOTES ABOUT THE CODE TIMER:

• There will sometimes be unavoidable rounding errors (like with OSC values 12, 24, 33 and 48) in calculating the period of each timer-

tick. The routines have been designed to help minimize these errors as much as possible.

• Steps 3) and 4) below can be used multiple times to time any number of code sections, outputing the results for each.
• Code Timer will increase the code size of your project
• If an overflow of the timer occurs (indicated by a 1 in the output text "Overflow:") the timing result will not be valid.

Select a higher prescale value.

• The higher the prescale, the less accurate the timing will be. So select the smallest prescale possible that will not overflow.
• Due to the nature of PBP commands, there is the possibility that some of the commands will not alway use the same number of

instruction cycles to complete a task. So, You are likely to see some variablility, and should keep this in mind if trying to do anything which relies on critical timing (which should probablybe handled in an interrupt).

TIMING BLOCKS OF CODE
1) Add an INCLUDE statement for this file: INCLUDE "CodeTimer.bas

2) Setup the timer with the following statement syntax: @ SETUP_CODE_TIMER tmr, ps

Where tmr = Timer number (0-3)
ps = Valid Prescale Value (see below)
Timer0: 1,2,4,8,16,32,64,128,256
Timer1: 1,2,4,8
Timer2: 1,4,16
Timer3: 1,2,4,8

Examples: @ SETUP_CODE_TIMER 0, 128 ; Timer0, Prescale 1:128

@ SETUP_CODE_TIMER 3, 1, ; Timer3, Prescale 1:1

2b) If you have a separate clock source for the timer, you can use the following DEFINE to set it for this must be typed exactly as shown. Add the appropriate value in MHz.

DEFINE CODETIMER_EXTCLK 10 ;10MHz clock for Timer

3) Place the following statement just PRIOR to the section of code you want to time: @ START_CODE_TIMER

..........................................Your Code Here

4) Place the following statement just AFTER to the section of code you want to time: @ STOP_CODE_TIMER You will end up with output similar to:

Time: 15.0276 msec
Tick Period: 0.4 usec
Timer Ticks: 37569
OSC Freq: 40 Mhz
Prescale: 4
Overflow: 0

USE PBP's DEBUG FUNCTION TO TIME INDIVIDUAL PBP COMMANDS

1) Add an INCLUDE statement for this file; INCLUDE CodeTimer.bas

2) Setup the timer with the following statement syntax; @ SETUP_CODE_TIMER_DEBUG trm

Where tmr = Timer number (0-3)

Examples:
@ SETUP_CODE_TIMER_DEBUG 0, ; Timer0
@ SETUP_CODE_TIMER_DEBUG 3, ; Timer3

3) Place the following statement just PRIOR to the section of code you want to time: @ START_CODE_TIMER_DEBUG ENABLE DEBUG

.......................................... Your Code Here

4) Place the following statement just AFTER to the section of code you want to time: @ STOP_CODE_TIMER_DEBUG DISABLE DEBUG

You will end up with output similar to:

Debug Addr: $5444
Time: .0404 msec
Tick Period: 0.1 usec
Timer Ticks: 404
OSC Freq: 40 Mhz
Prescale: 1
Overflow: 0

Debug Addr: $547A
Time: .0012 msec
Tick Period: 0.1 usec
Timer Ticks: 12
OSC Freq: 40 Mhz
Prescale: 1
Overflow: 0

Debug Addr: $548A
Time: .0006 msec
Tick Period: 0.1 usec
Timer Ticks: 6
OSC Freq: 40 Mhz
Prescale: 1
Overflow: 0

Total Ticks: 422
Time: .0422 msec

This shows the timing results for 3 PBP commands. The starting address for these commands is shown as "Debug Addr." At the bottom, if the number of timer ticks was less than 65536, then it will give you the Total Time of all the instructions. Otherwise, it will only give the total number of timer ticks

IMPORTANT NOTES ABOUT USING DEBUG:

• This code timer will not work with a prescale or external timer clock.
• Since PBP's DEBUG function add additional assembly instructions to code, code size will increase, so it's advised to use only with

a small number of instructions.

• There is some likelyhood the the number of ticks could actually be slightly less than reported. This is due to PBP adding code for

the debug functions and it is not possible to predetermine the exact number of instructions added.