RE: MPC565 hanging at temperature

Thank you Allan,
 
I did check through earlier posts looking for clues, but didn't come up
with anything. Our PU resistors are 1K on both PORESET, HRESET and
SRESET.
 
We let the unit cool down and it starts up again. I've looked at the RSR
and no PO reset has occurred but both EHRS and SWRS have occurred. We
don't know though whether the watchdog reset is the cause or effect.
I.e. which one occurred first.
 
Regards
Pete

________________________________

From: MPC500@... [mailto:MPC500@...] On Behalf
Of Dobbin Allan
Sent: 24 November 2008 15:54
To: MPC500@...
Subject: RE: [MPC500] MPC565 hanging at temperature



I remember previous posts about he the value of the HRESET resistor i.e.
reducing from 10K to 4.7k or 1k. Could you please search previous posts
forthis and see if it gives any improvement? What value of R are you
using?

- Allan

________________________________

From: MPC500@... <mailto:MPC500%40yahoogroups.com>
[mailto:MPC500@... <mailto:MPC500%40yahoogroups.com> ] On
Behalf
Of Pete James
Sent: Monday, November 24, 2008 5:14 AM
To: MPC500@... <mailto:MPC500%40yahoogroups.com>
Subject: [MPC500] MPC565 hanging at temperature

Hi all,

We have a problem with a MPC566 based ECU. We have manufactured several
batches of this product with no problems. The latest batch freeze at
temperatures over 80 degrees C. The MPC566 part is an MZ part so should
be good for 125 degrees.

We have checked all the supplies and they are correct.

PORESET is stable (not asserted)
HRESET is flicking up and down - presumably causing the reset of the
part, and generated internally

When the ambient temperature falls below 80 degrees the part runs
normally again. We have nothing connected to the HRESET line other than
the pull up resistor.

Any thoughts and help would be appreciated. It's baffling us as previous
batches have worked with no problems.

Best regards
Pete

Pete James
Technical Specialist/Chief Engineer - Electronics & Software
Prodrive
Kenilworth
Warwickshire
CV8 1NR
UK
DDI - +44 (0) 1676 536023
Email - pjames@... <mailto:pjames%40prodrive.com>
<mailto:pjames%40prodrive.com>

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