Hi,
I'm working on a similar hardware design. It has 4 current loops
that operate at up to 30 amps off of a 300 volt DC bus.
The inteface to the JTAG is exactly like that on the EVM board.
I had problems with the DSP hanging up due to glitches on the JTAG
port.
I found the solution to be connecting a 10k ohm pull down on the
PORT_RESET (this is on pin 2 on the DB25 connector)The resistor is on
the PCB near the 74LCX244 that receives the signals from the parallel
port.
I also found I had to add a good solid braided ground strap from the
housing of the 25 pin connector to the ground plane of the PCB. (the
DB25 uses a small molex connector with a short adapter cable to
connect to the board so the shield was not connected on the PCB end)
Kirk
Reply by Hutchings William-p23437●September 12, 20032003-09-12
How is
your JTAG lines configured in your target system. The /trst should be
driven low to hold the JTAG port in reset when you are not using this port. If
the /trst is not connected in your target system and is left to float this will
cause intermittant problems.
-----Original Message----- From: Bill Schintler
[mailto:w...@mchsi.com] Sent: Thursday, September 11, 2003 9:16
PM To: m...@yahoogroups.com Subject: [motoroladsp] Re:
DSP hang up with EMC disturbance
YES, I have been
having problems related to EMC with this processor! I am developing a
switching power supply which switches at 50 kHz (harmonics out to several
MHz), and handles several tens of amps, and up to a few kV. I am
using the 56F807 for all feedback loop control (DSP implimentation of
filters), ADC's, PWM generation, and user control. The processor
and associated signal conditioning electronics are galvanically isolated
from the high power circuitry.
Having the processor "hiccup" is *NOT*
good in this application. I am in the process of debugging these
issues. At this time, I can say that it appears that some of these
problems *ARE* related to the JTAG circuitry - but I'm not sure if
that's everything. I will post an update within a few days once
I do some further troubleshooting.
Regards - Bill
--- In
m...@yahoogroups.com, "mvigano" <mvigano@y...> wrote: > We use
56F807 with internal watchdog (COP) enabled but we experienced > a stop
of the DSP when we apply EMC disturbance like fast transient > or > elettrostatic > discharge. > Our application is an high
reliability one so we cannot simply reset > it > with an
external watchdog. > The problem seems to came from the JTAG port and
specially > from /TRST signal > (we have connected it in the
same way used on the evaluation board). > The only solution we found is
to connect togheter /RESET and /TRST > and keep > very short > the distance (no more than one inch) to the reset generator. > In
this arrangement we cannot use the emulator with the production >
board. > > Somebody has found the same sensivity on /TRST
signal? > > Marco Vigano' > >
Microelettrica Scientifica S.p.A. > via Alberelle 56 > 20089
Rozzano (MI) > Italy > > Tel. :+39-02-575731 > Fax :+39-02-57510940 > mailto:mvigano@m...
_____________________________________ 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:
Reply by Bill Schintler●September 12, 20032003-09-12
YES, I have been having problems related to EMC with this processor!
I am developing a switching power supply which switches at 50 kHz
(harmonics out to several MHz), and handles several tens of amps, and
up to a few kV. I am using the 56F807 for all feedback loop control
(DSP implimentation of filters), ADC's, PWM generation, and user
control. The processor and associated signal conditioning electronics
are galvanically isolated from the high power circuitry.
Having the processor "hiccup" is *NOT* good in this application. I
am
in the process of debugging these issues. At this time, I can say
that it appears that some of these problems *ARE* related to the JTAG
circuitry - but I'm not sure if that's everything. I will post an
update within a few days once I do some further troubleshooting.
Regards - Bill
--- In , "mvigano" <mvigano@y...> wrote: > We use 56F807 with internal watchdog (COP) enabled
but we experienced
> a stop of the DSP when we apply EMC disturbance like fast transient
> or
> elettrostatic
> discharge.
> Our application is an high reliability one so we cannot simply reset
> it
> with an external watchdog.
> The problem seems to came from the JTAG port and specially
> from /TRST signal
> (we have connected it in the same way used on the evaluation board).
> The only solution we found is to connect togheter /RESET and /TRST
> and keep
> very short
> the distance (no more than one inch) to the reset generator.
> In this arrangement we cannot use the emulator with the production
> board.
>
> Somebody has found the same sensivity on /TRST signal?
>
> Marco Vigano'
>
> Microelettrica Scientifica S.p.A.
> via Alberelle 56
> 20089 Rozzano (MI)
> Italy
>
> Tel. :+39-02-575731
> Fax :+39-02-57510940
> mailto:mvigano@m...
Reply by Hutchings William-p23437●September 11, 20032003-09-11
The /trst
line resets the internal JTAG registers. If you do not provide a active /trst
the JTAG registers can end up in a random state possibly with a value that puts
the processor in a debug state. The /trst needs to be driven active at power up.
You can also tie it permantly active in a system that you are not using with the
debugger. You can use a jumper or switch to allow debugger and non debugger
operation similar to how the EVM operates.
[Hutchings
William-p23437] -----Original Message----- From: mvigano [mailto:m...@yahoo.com] Sent: Thursday,
September 11, 2003 9:50 AM To: m...@yahoogroups.com Subject: [motoroladsp] DSP hang up with EMC disturbance
We use 56F807 with internal watchdog
(COP) enabled but we experienced a stop of the DSP when we apply EMC
disturbance like fast transient or elettrostatic discharge. Our application is an high reliability one so we cannot simply reset it with an external watchdog. The problem seems to came from the
JTAG port and specially from /TRST signal (we have connected it in
the same way used on the evaluation board). The only solution we found is
to connect togheter /RESET and /TRST and keep very short the
distance (no more than one inch) to the reset generator. In this
arrangement we cannot use the emulator with the production board.
Somebody has found the same sensivity on /TRST signal?
Marco
Vigano'
Microelettrica Scientifica S.p.A. via Alberelle
56 20089 Rozzano (MI) Italy
_____________________________________ 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:
We use 56F807 with internal watchdog (COP) enabled but we experienced
a stop of the DSP when we apply EMC disturbance like fast transient
or
elettrostatic
discharge.
Our application is an high reliability one so we cannot simply reset
it
with an external watchdog.
The problem seems to came from the JTAG port and specially
from /TRST signal
(we have connected it in the same way used on the evaluation board).
The only solution we found is to connect togheter /RESET and /TRST
and keep
very short
the distance (no more than one inch) to the reset generator.
In this arrangement we cannot use the emulator with the production
board.
Somebody has found the same sensivity on /TRST signal?
Marco Vigano'
Microelettrica Scientifica S.p.A.
via Alberelle 56
20089 Rozzano (MI)
Italy