>I am not quite sure what lines need a defined state
during power-up (except
>for the obvious ones). Do you know for the 21065L?
Me neither. But look for ones that share pull-up and or pull-down resistors.
If there are any, they might be suspect.
Jeff Brower
Signalogic
>> -----Original Message-----
>> From: Jeff Brower [mailto:]
>> Sent: Monday, March 05, 2001 3:13 PM
>> To: Daniel Weiss
>> Cc:
>> Subject: Re: [adsp] 21065L power problem
>>
>>
>> Daniel-
>>
>> >Has anybody ever experienced power-up problems with the
>> 21065L Sharc? It
>> >is kind of a problem where the chip does not seem to
"start"
>> properly.
>> >The reset line does not help. It has to do with the 3.3V
>> power - either
>> >the ramping of the 3.3V voltage or maybe sequencing of the
>> 5V and 3.3V
>> >supplies we use in our system. I found that when I delay the
3.3V
>> >ramp-up relative to the 5V then the problem is less severe.
>> Is it true
>> >that there are bias voltage generators inside the Sharc
(substrate
>> >voltage?) which might not start properly?
>>
>> Also check for multiple mode/config lines tied to the same
>> pull-up or pull-down
>> resistors. I've seen a case before where one or more such
>> lines tied together
>> were temporarily outputs during reset, influencing the other
>> signals and causing
>> the processor to go into the wrong state. The solution was
>> to separate the
>> signals and use more pull-up / pull-down Rs.
>>
>> Jeff Brower
>> DSP sw/hw engineer
>> Signalogic
> Thanks, Jeff, for the hints.
>
> I am not quite sure what lines need a defined state during power-up
(except
> for the obvious ones). Do you know for the 21065L?
>
> Daniel
>
> > -----Original Message-----
> > From: Jeff Brower [mailto:]
> > Sent: Monday, March 05, 2001 3:13 PM
> > To: Daniel Weiss
> > Cc:
> > Subject: Re: [adsp] 21065L power problem
> >
> >
> > Daniel-
> >
> > >Has anybody ever experienced power-up problems with the
> > 21065L Sharc? It
> > >is kind of a problem where the chip does not seem to
"start"
> > properly.
> > >The reset line does not help. It has to do with the 3.3V
> > power - either
> > >the ramping of the 3.3V voltage or maybe sequencing of the
> > 5V and 3.3V
> > >supplies we use in our system. I found that when I delay the
3.3V
> > >ramp-up relative to the 5V then the problem is less severe.
> > Is it true
> > >that there are bias voltage generators inside the Sharc
(substrate
> > >voltage?) which might not start properly?
> >
> > Also check for multiple mode/config lines tied to the same
> > pull-up or pull-down
> > resistors. I've seen a case before where one or more such
> > lines tied together
> > were temporarily outputs during reset, influencing the other
> > signals and causing
> > the processor to go into the wrong state. The solution was
> > to separate the
> > signals and use more pull-up / pull-down Rs.
> >
> > Jeff Brower
> > DSP sw/hw engineer
> > Signalogic
> >
> >
> > _____________________________________
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> > ">http://docs.yahoo.com/info/terms/
>
> _____________________________________
> Note: If you do a simple "reply" with your email client, only the
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all" if you want
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> _____________________________________
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Reply by Daniel Weiss●March 6, 20012001-03-06
Thanks, Jeff, for the hints.
I am not quite sure what lines need a defined state during power-up (except
for the obvious ones). Do you know for the 21065L?
Daniel
> -----Original Message-----
> From: Jeff Brower [mailto:]
> Sent: Monday, March 05, 2001 3:13 PM
> To: Daniel Weiss
> Cc:
> Subject: Re: [adsp] 21065L power problem
> Daniel-
>
> >Has anybody ever experienced power-up problems with the
> 21065L Sharc? It
> >is kind of a problem where the chip does not seem to
"start"
> properly.
> >The reset line does not help. It has to do with the 3.3V
> power - either
> >the ramping of the 3.3V voltage or maybe sequencing of the
> 5V and 3.3V
> >supplies we use in our system. I found that when I delay the 3.3V
> >ramp-up relative to the 5V then the problem is less severe.
> Is it true
> >that there are bias voltage generators inside the Sharc (substrate
> >voltage?) which might not start properly?
>
> Also check for multiple mode/config lines tied to the same
> pull-up or pull-down
> resistors. I've seen a case before where one or more such
> lines tied together
> were temporarily outputs during reset, influencing the other
> signals and causing
> the processor to go into the wrong state. The solution was
> to separate the
> signals and use more pull-up / pull-down Rs.
>
> Jeff Brower
> DSP sw/hw engineer
> Signalogic
> _____________________________________
> Note: If you do a simple "reply" with your email client, only
> the author of this message will receive your answer. You
> need to do a "reply all" if you want your answer to be
> distributed to the entire group.
>
> _____________________________________
> About this discussion group:
>
> To Join: Send an email to
>
> To Post: Send an email to
>
> To Leave: Send an email to
>
> Archives: http://www.egroups.com/group/adsp
>
> Other Groups: http://www.dsprelated.com
> ">http://docs.yahoo.com/info/terms/
Reply by Jeff Brower●March 5, 20012001-03-05
Daniel-
>Has anybody ever experienced power-up problems with
the 21065L Sharc? It
>is kind of a problem where the chip does not seem to "start"
properly.
>The reset line does not help. It has to do with the 3.3V power - either
>the ramping of the 3.3V voltage or maybe sequencing of the 5V and 3.3V
>supplies we use in our system. I found that when I delay the 3.3V
>ramp-up relative to the 5V then the problem is less severe. Is it true
>that there are bias voltage generators inside the Sharc (substrate
>voltage?) which might not start properly?
Also check for multiple mode/config lines tied to the same pull-up or
pull-down
resistors. I've seen a case before where one or more such lines tied
together
were temporarily outputs during reset, influencing the other signals and
causing
the processor to go into the wrong state. The solution was to separate the
signals and use more pull-up / pull-down Rs.
Jeff Brower
DSP sw/hw engineer
Signalogic
Reply by Daniel Weiss●March 5, 20012001-03-05
Hello all
Has anybody ever experienced power-up problems with the 21065L Sharc? It
is kind of a problem where the chip does not seem to "start"
properly.
The reset line does not help. It has to do with the 3.3V power - either
the ramping of the 3.3V voltage or maybe sequencing of the 5V and 3.3V
supplies we use in our system. I found that when I delay the 3.3V
ramp-up relative to the 5V then the problem is less severe. Is it true
that there are bias voltage generators inside the Sharc (substrate
voltage?) which might not start properly?
Thanks for your help
Daniel Weiss
WEISS ENGINEERING LTD. - Professional Digital Audio Products
Florastrasse 42 8610 Uster Switzerland
phone: +41 1 940 20 06, fax: +41 1 940 22 14
email: web: http://www.weiss.ch
Subscribe to our maillist at http://groups.yahoo.com/group/weiss-audio