Forums

NMI on 6713

Started by Bernhard 'Gustl' Bauer May 2, 2005
Hi,

is there any way to check the input on NMI pin?

I have NMI connected to a power down sensor. When a brown out condition
happens, I get a NMI, but now reset. So I must restart manually.

TIA

Gustl



Hello Gustl,
 
If you don't have any backup power, I would expect that you want want to just pull reset on power low.  keep reset low as long as you can.  when power comes back up, keep reset low until power is 'good'.  gee - that sounds just like a voltage supervisor chip  :-)
 
mikedunn

Bernhard 'Gustl' Bauer <g...@quantec.de> wrote:
Hi,

is there any way to check the input on NMI pin?

I have NMI connected to a power down sensor. When a brown out condition
happens, I get a NMI, but now reset. So I must restart manually.

TIA

Gustl

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Hello Mike,

I have a voltage supervisor chip. If voltage drops below 3V I get an
NMI. If voltage drops below 2V I get an RESET. My NMI has to store some
values into flash and wait until the reset happens.

But what if I get a voltage drop to 2.5V and then it comes back up to
3.3V again? In this case I never get the reset and must restart
manually. So I have to check the NMI pin by SW. How can I do this?

Gustl

Mike Dunn wrote:
> Hello Gustl,
>
> If you don't have any backup power, I would expect that you want want to
> just pull reset on power low. keep reset low as long as you can. when
> power comes back up, keep reset low until power is 'good'. gee - that
> sounds just like a voltage supervisor chip :-)
>
> mikedunn
>
> Bernhard 'Gustl' Bauer <gustl@gust...> wrote:
>
> Hi,
>
> is there any way to check the input on NMI pin?
>
> I have NMI connected to a power down sensor. When a brown out condition
> happens, I get a NMI, but now reset. So I must restart manually.
>
> TIA
>
> Gustl > NEW! You can now post a message or access and search the archives of
> this group on DSPRelated.com:
> http://www.dsprelated.com/groups/c6x/1.php
>




Gustl-

> I have a voltage supervisor chip. If voltage drops below 3V I get an
> NMI. If voltage drops below 2V I get an RESET. My NMI has to store some
> values into flash and wait until the reset happens.
>
> But what if I get a voltage drop to 2.5V and then it comes back up to
> 3.3V again? In this case I never get the reset and must restart
> manually. So I have to check the NMI pin by SW. How can I do this?

Run NMI also to a GPIO? Since I'm sure you've already thought (wished) of that, then
I might guess the device is a BGA package and the hardware designer buried all the
unused GPIO pins :(

-Jeff > Mike Dunn wrote:
> > Hello Gustl,
> >
> > If you don't have any backup power, I would expect that you want want to
> > just pull reset on power low. keep reset low as long as you can. when
> > power comes back up, keep reset low until power is 'good'. gee - that
> > sounds just like a voltage supervisor chip :-)
> >
> > mikedunn
> >
> > Bernhard 'Gustl' Bauer <gustl@gust...> wrote:
> >
> > Hi,
> >
> > is there any way to check the input on NMI pin?
> >
> > I have NMI connected to a power down sensor. When a brown out condition
> > happens, I get a NMI, but now reset. So I must restart manually.
> >
> > TIA
> >
> > Gustl



So the only way is to connect NMI to a second pin? I still have some,
but on the other side :-(

It would be much easier to have an inside TMS solution.

Gustl

Jeff Brower wrote:

> Gustl- >> I have a voltage supervisor chip. If voltage drops below 3V I get
>> an NMI. If voltage drops below 2V I get an RESET. My NMI has to
>> store some values into flash and wait until the reset happens.
>>
>> But what if I get a voltage drop to 2.5V and then it comes back up
>> to 3.3V again? In this case I never get the reset and must restart
>> manually. So I have to check the NMI pin by SW. How can I do this? > Run NMI also to a GPIO? Since I'm sure you've already thought
> (wished) of that, then I might guess the device is a BGA package and
> the hardware designer buried all the unused GPIO pins :(
>
> -Jeff >
>> Mike Dunn wrote:
>>
>>> Hello Gustl,
>>>
>>> If you don't have any backup power, I would expect that you want
>>> want to just pull reset on power low. keep reset low as long as
>>> you can. when power comes back up, keep reset low until power is
>>> 'good'. gee - that sounds just like a voltage supervisor chip
>>> :-)
>>>
>>> mikedunn
>>>
>>> Bernhard 'Gustl' Bauer <gustl@gust...> wrote:
>>>
>>> Hi,
>>>
>>> is there any way to check the input on NMI pin?
>>>
>>> I have NMI connected to a power down sensor. When a brown out
>>> condition happens, I get a NMI, but now reset. So I must restart
>>> manually.
>>>
>>> TIA
>>>
>>> Gustl




Gustl-

> So the only way is to connect NMI to a second pin? I still have some,
> but on the other side :-(
>
> It would be much easier to have an inside TMS solution.

Well there is always another way, always -- and it might even be elegant once you
find it. But the question is how long is it going to take? A GPIO pin seems like a
fast way to get around this and move on to additional challenging areas of the
design.

-Jeff

> Jeff Brower wrote:
>
> > Gustl-
> >
> >
> >> I have a voltage supervisor chip. If voltage drops below 3V I get
> >> an NMI. If voltage drops below 2V I get an RESET. My NMI has to
> >> store some values into flash and wait until the reset happens.
> >>
> >> But what if I get a voltage drop to 2.5V and then it comes back up
> >> to 3.3V again? In this case I never get the reset and must restart
> >> manually. So I have to check the NMI pin by SW. How can I do this?
> >
> >
> > Run NMI also to a GPIO? Since I'm sure you've already thought
> > (wished) of that, then I might guess the device is a BGA package and
> > the hardware designer buried all the unused GPIO pins :(
> >
> > -Jeff
> >
> >
> >
> >> Mike Dunn wrote:
> >>
> >>> Hello Gustl,
> >>>
> >>> If you don't have any backup power, I would expect that you want
> >>> want to just pull reset on power low. keep reset low as long as
> >>> you can. when power comes back up, keep reset low until power is
> >>> 'good'. gee - that sounds just like a voltage supervisor chip
> >>> :-)
> >>>
> >>> mikedunn
> >>>
> >>> Bernhard 'Gustl' Bauer <gustl@gust...> wrote:
> >>>
> >>> Hi,
> >>>
> >>> is there any way to check the input on NMI pin?
> >>>
> >>> I have NMI connected to a power down sensor. When a brown out
> >>> condition happens, I get a NMI, but now reset. So I must restart
> >>> manually.
> >>>
> >>> TIA
> >>>
> >>> Gustl