live debug vs trace

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can someone tell me what is the difference between live debug and trace?

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Trace, if you can find a debugger which supports it, will record a certain ammout of instructions the micro has performed until stopped so you can see where it has been.

I don't quite understand what you mean by "live debug". Do you mean a continuosly updated system status like variable etc. while the micro is running? I don't think any Atmel tools can do that but I may be wrong.

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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It's the same things as the difference between "real life" and history ;-)

(one is what's happening now, the other is what happened a while back).

A debugger that offers trace is simply one that is writing down what happens as it goes along.

Unfortunately to do that "writing down" (at full speed) is quite a complex technical thing to do and only Atmels original chip replacing in circuit emulators (ICE50/ICE200) had the capability. Modern "ICE" are not ICE at all (they don't replace the CPU in circuit - they listen on the edges) and they cannot do this "trick".

(having said that it's vaguely possible the $599 AVR One! might be able to - if so then the recent offer that saw it selling for $199 makes it an ever greater bargain!).

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Quote:

the recent offer that saw it selling for $199 makes it an ever greater bargain

Which has now ended.

[yeah I just checked for that JTAGICEmkII v JTAGICE3 thread - what a crying shame - once it had dropped so much I thought there was no way it'd go back up to $599 - but who can predict Atmel's marketing? Cliff]

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clawson wrote:
... it's vaguely possible the $599 AVR One! might be able to - ...
Only for AVR32 and hopefully forthcoming for SAM3/SAM4. For AVR the simulator is "good enough" since it has a model for most of an AVR; I don't know of any 8-bit MCU that has a trace.
Ref. Atmel AVR ONE! Features
Edit: added ref.

"Dare to be naïve." - Buckminster Fuller

Last Edited: Tue. May 8, 2012 - 10:00 AM
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JohanEkdahl wrote:
Quote:

the recent offer that saw it selling for $199 makes it an ever greater bargain

Which has now ended.

[yeah I just checked for that JTAGICEmkII v JTAGICE3 thread - what a crying shame - once it had dropped so much I thought there was no way it'd go back up to $599 - but who can predict Atmel's marketing? Cliff]


What is that red text color supposed to indicate ? Did Johan or Cliff write that in Johan's post ?

Sid

Life... is a state of mind

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js wrote:
I don't quite understand what you mean by "live debug".
From AVR ONE! at Atmel Store:
"AVR ONE! supports LiveDebug, which makes it possible to attach to a running target non-intrusively"

"Dare to be naïve." - Buckminster Fuller

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Quote:

id Johan or Cliff write that in Johan's post ?


Cliff wrote it. That's why it says "Cliff" at the end.

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clawson wrote:
Quote:

id Johan or Cliff write that in Johan's post ?


Cliff wrote it. That's why it says "Cliff" at the end.

I can write something and put "Cliff" at the end too.

What is your reasoning for editing his post like that ? How does that add to the discussion ? What is gained, that you couldn't gain by posting a reply ?

You should take it easy with your moderating privileges. Use them when there is something that needs to be moderated, otherwise you should leave other people's posts alone.

Sid

Life... is a state of mind

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Live Debug is somewhat more intrusive, because you get nothing until it has stopped. Then, you can read the state of memory, registers, and, such. BUT, you have no information about how it got to that point. You can get it stopped either by having the debugger Pause, or you can set a breakpoint that causes the debugger to pause.

Theoretically, trace is relatively non-intrusive until you start figuring out how to actually implement it. Trace implies building a history of what the chip does. It is very resource intensive because for every execution step, a memory address has to be stored (what is going to "store" it, and where?). Also, you may need to know the status of various registers - going to save all of them? (again, what does it, where?).

So, while trace may be what you really would like, its not so easy to achieve, in practice. For most of us, debug works pretty well. And, it works WAAAAY better than nothing!

Jim

 

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