A simple and basic question

[T.Jackson]

I think what Ted is actually asking is something like this ...

DEFINE OSC 20

WHILE Zaehler_Word <> 60000
   Zaehler_Word = Zaehler_Word + 1
WEND

With a 20MHz osc, how long did it take for Zaehler_Word to reach 60,000?

Trent Jackson

[Acetronics2]

Hi, Trent

Once, the littles things I raised up have been solved ... a little round in MPSIM is the next step ...

To be sure ...

Alain

[T.Jackson]

I think that the question is very "meaningful" and not so easy to accurately answer without going into assembly routines. I say this because you need to know the number of instruction cycles needed for each mnemonic, the time taken for each cycle (around 1uS at 4MHz I think), and finally what OP codes are driving the PBP instructions. You need to have a good understanding of assembly code to be able to work it out, which I don't have, otherwise I'd provide an answer.

Trent Jackson

[Acetronics2]

Hi,

I remember Darrel wrote a little bit of program to measure program parts duration ... a SEARCH through those columns will be welcome.

The second way is to use MPSIM ( part of MPLAB ) with the stopwatch : result is quite perfect !

Alain

[T.Jackson]

@20MHz I'm guessing ~3uS per iteration of the loop.

Trent Jackson

[Ted's]

I do not understand your answers.

What you need to take out of this:

If you loop a variable from zero to 60000 on a pic being driven by a 20Mhz Quartz using the pbp code WHILE without adding a Pauseus XY into the loop, what does this value tell me about the time being elapsed.

[Acetronics2]

I do not understand your answers.

What you need to take out of this:

.

So, WE CANNOT ANSWER YOUR QUESTION ...

IF A = 0 ... the loop won't be executed ...

IF A != 0 ... The loop is infinite ...

so, the loop will last as long as A != 0 ...


This is what you have to take out of your hasty code snippet ...

Alain

[Ted's]

We? Are you schizophrenic?