[SI-LIST] Re: Reset problem with power supply
- From: Manickavelu M. <manickavelu_m@xxxxxxxxxxxx>
- To: "'for_si2003@xxxxxxxxx'" <for_si2003@xxxxxxxxx>, "'olaney@xxxxxxxx'" <olaney@xxxxxxxx>
- Date: Sun, 7 Dec 2008 09:02:55 +0530
Dear Vikash,
If the processor tries to access the flash before the flash is fully up, then
you just need to delay the first access to the flash by implementing a POR
sequence that will allow the processor to start after the power to the flash is
stabilzed.
----- Original Message -----
From: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx>
To: olaney@xxxxxxxx <olaney@xxxxxxxx>
Cc: si-list@xxxxxxxxxxxxx <si-list@xxxxxxxxxxxxx>
Sent: Sun Dec 07 08:49:28 2008
Subject: [SI-LIST] Re: Reset problem with power supply
Orin,
Thnaks for taking time to write. I finally found that the processor was booting
everytime. But it did not get the first byte from the Flash. Flash did not seem
to start.
I finally solved the problem by using a small controller to generate a POR
followed by double HReset ( Low then High, then again low and then high).
Thanks everyone for reply
Vikas
http://referencedesigner.com
--- On Fri, 12/5/08, olaney@xxxxxxxx <olaney@xxxxxxxx> wrote:
> From: olaney@xxxxxxxx <olaney@xxxxxxxx>
> Subject: Re: [SI-LIST] Reset problem with power supply
> To: for_si2003@xxxxxxxxx
> Cc: si-list@xxxxxxxxxxxxx
> Date: Friday, December 5, 2008, 2:57 PM
> Cable inductance absolutely should not be an issue. If it
> actually is,
> be grateful that you found a design flaw before you reached
> production!
> This might be related to the power risetime. Your POR
> circuit needs to
> operate properly even if you slowly bring the voltage up
> manually. Some
> circuits depend on fast power risetime to operate properly,
> and work
> OK... most of the time. The worst ones capacitor couple
> the voltage bus
> into a transistor. Not only do these fail to reset on a
> slow rise, if an
> aluminum electrolytic cap is used, the value will drop with
> age as it
> dries out and eventually the circuit won't work even
> for normal supply
> risetime. A Schmitt trigger is a good basis for a
> bullet-proof approach,
> as are any number of supervisor ICs that also check for
> overvoltage,
> brown-out, and the like.
>
> In any instance, if you can section the power distribution,
> start by
> running everything off the bench supply, then one by one
> move each
> section to power through the cable. When the problem
> reappears you have
> found where to dig deeper. Power up and down between each
> change, rather
> than doing this with a live circuit.
>
> Orin Laney
>
> On Fri, 5 Dec 2008 12:39:22 -0800 (PST) V S
> <for_si2003@xxxxxxxxx>
> writes:
> > When I power my board using a bench power supply it
> boots. When I try
> > to plug in the cable, with the one end of the cable
> hooked to the
> > same power supply in power on position it does not. My
> question is
> > what difference cable inductance makes ? The failure
> looks like
> > between processor and Flash core, as, the processor is
> always alive.
> >
> > The processor is freescale MX27. I am using national
> Semi LM2717-ADJ
> > IC to generate 1.8V for memory IO, 1.5V for core and
> PLL, 2.775V for
> > processor IO and 3.15 for other IO. A POR is generated
> using Schimtt
> > Trigger. The HRESET is generated using the same
> schmitt Trigger
> > 74LCX07MX.
> >
> > Any one faced similar situation ?
> >
> >
> >
> >
> >
> >
> ------------------------------------------------------------------
> > To unsubscribe from si-list:
> > si-list-request@xxxxxxxxxxxxx with
> 'unsubscribe' in the Subject
> > field
> >
> > or to administer your membership from a web page, go
> to:
> > //www.freelists.org/webpage/si-list
> >
> > For help:
> > si-list-request@xxxxxxxxxxxxx with 'help' in
> the Subject field
> >
> >
> > List technical documents are available at:
> > http://www.si-list.net
> >
> > List archives are viewable at:
> >
> //www.freelists.org/archives/si-list
> > or at our remote archives:
> >
> http://groups.yahoo.com/group/si-list/messages
> > Old (prior to June 6, 2001) list archives are viewable
> at:
> > http://www.qsl.net/wb6tpu
> >
> >
> >
> >
>
> ____________________________________________________________
> Click here to find experienced pros to help with your home
> improvement project.
> http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw2eRIUtqmLApMYi2q6sfe8Q1dotgkKq2bAFfHxxslhTTv7gq/
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.net
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
This message (including attachment if any) is confidential and may be
privileged. If you have received this message by mistake please notify the
sender by return e-mail and delete this message from your system. Any
unauthorized use or dissemination of this message in whole or in part is
strictly prohibited. E-mail may contain viruses. Before opening attachments
please check them for viruses and defects. While MindTree Limited (MindTree)
has put in place checks to minimize the risks, MindTree will not be responsible
for any viruses or defects or any forwarded attachments emanating either from
within MindTree or outside.
Please note that e-mails are susceptible to change and MindTree shall not be
liable for any improper, untimely or incomplete transmission.
MindTree reserves the right to monitor and review the content of all messages
sent to or from MindTree e-mail address. Messages sent to or from this e-mail
address may be stored on the MindTree e-mail system or else where.
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.net
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
