Differences between HW reset and COP reset

[PsychoDebugger]

Which are the differences between the  HW reset and aCOP reset ?

I've no Serial Monitor in my board.
When I use HW reset the software in the board restart,
bit when I use a COP reset it doesn't.

With Serial Monitor in my board i didn't see any difference.
Is not a COP reset equivalent to HW reset without Serial Monitor ?

[Shugie]

To expand on Alban's comment a bit, there are a few different reset vecotrs that have to be initilized. The watchdog having a different reset vector is useful in the case of adding a debugging function when the watchdog is reset to somehow communicated what happened that caused that reset. Here is a thread from the forum what I show what I did to initilize the reset vectors in Codewarrior.

http://forums.freescale.com/freescale/board/message?board.id=16BITCOMM&thread.id=4223

Best of luck.

[Shugie]

And as an explanation of the serial monitor. What the serial monitor does is that it initilizes all the resets, pll, etc... then looks to see if it should jump to user code or loop its own code waiting for a program to be loaded. This means that when you remove the serial monitor it is your responsiblity to do all of this. Codewarrior took care of all of it for me when I did the project wizard except for the watchdog reset. This is why you are having problems.

[PsychoDebugger]

Thank you for the answer.

Now i've loaded Serial Monitor again, and all works,
but  I'm going to study the vectors and how to jump to my code without serial monitor.

I'll say you the results..if there will be

[Alban]

Hello,

There is no real difference for the internal circuitry, a reset is a reset.
But you can see a difference on the RESET pin between an internal reset and an external reset.

Let's take the C128 datasheet. But this also applied on others  Look at figures 9.26 and 9.27 page 285.
Because a drawing is sometimes better than a long speech

Cheers,
Alban.

[PsychoDebugger]

Hi Alban,

I thought as you say that a reset is a reset.
But there's something that i don't understand.

I use NE64 and when i use PIN reset it works fine,
instead COP reset does't work yet.
Previously i used Serial Monitor , i tested my firmware and it worked.
The only change i've done is that now i've not Serial Monitor.

MyReset function has these two instruction:

Code:

MyReset()
{
    COPCTL = 0x01;    // COP activated with shortest timeout
    ARMCOP = 0x47;    // no 0x55 and 0xAA
}

Really i see that reset LED does't light on....
Is there something i have to be care to in firmware now that i'm working without serial monitor?





Message Edited by PsychoDebugger on 2007-07-30 11:25 AM

Message Edited by PsychoDebugger on 2007-07-30 11:25 AM

[Alban]

Well, I may have an good idea:

The COP Reset is another vector from the PIN Reset !
You need to take care of the COP Reset from Vector $FFFA-$FFFB.

Cheers,
Alban.