Re: PORESET and SWT
"vijayanandl" <[email protected]>
| Newsgroups | gmane.comp.hardware.motorola.microcontrollers |
|---|---|
| Message-ID | <[email protected]> |
Hi Peter,Allan
I faced the same timeout problem. Sorry for replying so
late I was on vacation. I guess you have already solved the problem.
In my case the pull up resistor 10k was too high. When the POR pull
up was reduced to 1K the system did a proper POR.
The whole problem arose because there should ideally be a delay of
abt 20ms between POR and HReset. With the debugger(BDI) interface
there wont be the 14 s timeout.
The power supervisory circuit in our board was ok and HReset followed
POR after the POR pullup was changed. So I guess it was a design
problem on our board.
Regards
Vijay
--- In [email protected], "Peter Allen \(Yahoo\)"
<p_g_allen@y...> wrote:
> sorry I should have made it clear that when I connect the debugger
I am
> attaching to a program running in flash and am reseting the board
using
> the reset command. On my eval board I can get the code to run by
> pressing HRESET or SRESET buttons inside the 3s window (I can't do
this
> on my board since I have no reset switch).
>
> thanx heaps for the suggestions.
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
Behalf
> Of alex shulman
> Sent: Thursday, 18 August 2005 12:46 AM
> To: [email protected]
> Subject: RE: [MPC500] PORESET and SWT
>
>
> Peter,
>
> The problem seems to be related to your software, i.e.
> MCU initialization.
>
> When you are running your board with attached debugger
> it executes some initializations in the MCU to allow
> seamless debugging. Usually debuggers reprogram SYPCR
> register (which is writable once) to disable watchdog,
> sometimes also they program CS logic to allow the
> external memories access. Also debuggers program ICTRL
> register to define CPU serialization and show cycles -
> for code tracers. (When debugger is attached to the
> MCU
> ICTRL can not be changed by user code).
>
> The debugger initialization code is customizable and
> you can review it to see what you are missing in your
> application software.
>
> Regards
> Alex.
>
> --- "Peter Allen (Yahoo)" <p_g_allen@y...>
> wrote:
>
> > 1k pull ups on resets haven't resolved the problem.
> > I have notice a
> > similar problem using our Axiom MPC566EVB only here
> > the timeout is ~3
> > seconds and I scope the CLKOUT @ 56MHz appears to be
> > the same problem
> > only the EVB has already locked at 56MHz rather than
> > 20MHz.
> >
> > Having read some other posts I noticed that when I
> > use my debugger to
> > force a reset inside the 7s window after a PORESET
> > the device boots
> > immediatly. I also tried with the eval board and
> > notice that same thing
> > when using either SRESET or HRESET within the 3s
> > window post PORESET.
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf
> > Of Dobbin Allan-r11834
> > Sent: Monday, 1 August 2005 12:57 PM
> > To: '[email protected]'
> > Subject: RE: [MPC500] PORESET and SWT
> >
> >
> > 7secs is the WDOG timeout if you're using a 20MHz
> > crystal. If you don't
> > reset properly, the WDOG kicks in, everything is
> > reset and things run OK
> > after that.
> >
> > What value of pull-up do you have on HRESET? 10K is
> > too high (may be an
> > errata). The rise time is too slow and modclk, etc
> > don't get sampled
> > correctly. Reduce the HREST PU to 1K or 2K and see
> > if that solve sthe
> > problem.
> >
> > (Vijay - you should have posted your similar issue
> > on the group.)
> >
> > Allan
> >
> >
> > This sounds like a problem very similar to one that
> > someone else was
> > having a month or two ago - it was someone from this
> > group, but I don't
> > think the emails string was actually posted on the
> > site. Perhaps they
> > can reply. I think their problem ended up being too
> > high a pull up on
> > one of the reset lines, possibly POR. But that
> > resulted in too slow a
> > POR time - check the spec but yours seems OK.
> >
> > What was happening was POR was asserting too fast,
> > things weren't reset
> > correctly including PLL locking, and sebveral
> > seconds later the watchdog
> > would kick in and provide an HRESET and things run
> > fine afterwards. Try
> > reducing the POR
> >
> > Allan
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf
> > Of Peter Allen \(Yahoo\)
> > Sent: Sunday, July 31, 2005 6:46 PM
> > To: [email protected]
> > Subject: RE: [MPC500] PORESET and SWT
> >
> >
> > I have a revised problem.
> >
> > At POR the PORESET is a sserted by the power supply
> > (MC33998) ~22ms.
> > HRESET in negated
> > SRESET is negated
> >
> > ENGCLK (i didn't run CLKOUT from under the device)
> > starts at 312.5kHz
> > (or 20MHz/64) and then ~7s later HRESET is asserted
> > by the MPC566 and
> > the device restarts and function correctly. I can't
> > find a reason for
> > the problem.
> >
> > Thanks
> >
> > Peter Allen
> > Haltech Design Engineer
> > www.haltech.com <http://www.haltech.com/>
> > ph: 95252400
> > fax: 95252991
> >
> >
> >
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf
> > Of Dobbin Allan-r11834
> > Sent: Tuesday, 26 July 2005 11:29 PM
> > To: '[email protected]'
> > Subject: RE: [MPC500] PORESET and SWT
> >
> >
> > On the Axiom board, it sounds liekt he POR time is
> > not long enough, but
> > I would have suspected that h/w to be correct. Your
> > other h/w is a bit
> > of a mystery i.e. why the PIT wouldn't work but
> > other clocks would. Is
> > it possible the wrong clock source has been selected
> > for the timer? As
> > far as guessing your sysclk speed - look at the
> > CLKOUT signal.
> >
> > Allan
> >
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf
> > Of Peter Allen \(Yahoo\)
> > Sent: Monday, July 25, 2005 8:49 PM
> > To: [email protected]
> > Subject: [MPC500] PORESET and SWT
> >
> >
> > I just got some hardware back and can get code into
> > flash. The device
> > comes out of reset but doesn't boot withou BDM
> > intervention (ie. I
> > attach to code already on target and then use the
> > reset command and the
> > code starts running as expected). I have also
> > noticed that the PIT
> > doesn't always start working but serial coms and TPU
> > run ok and the SWT
> > doesn't ever time out to cause a reset.
> >
> > Things I know (I think):
> >
> > device is operating at desired 56MHz since:
> > baud rate is tied to this.
> > TPU functions are producing the correct timing
> > patterns.
> >
> > I noticed that on my Axiom eval board when i used
> > the POReset the code
> > would not boot until the watchdog timer ran out and
> > and then everything
> > would work OK. I I used the Hreset or Sreset the
> > system would bot
> > straight away (power is applied to the board at all
> > times).
> >
> > If anyone has some wisdom on this problem I would
> > greatly appreciate the
> > help
> >
> > Peter Allen
> > Haltech Design Engineer
> > www.haltech.com <http://www.haltech.com/>
> > ph: 95252400
> > fax: 95252991
> >
> >
> >
> >
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