FPGA Central

Hello,

Im in embedded software development, but interested in developing a device
which can caputure trace information from a Nexus class-3 compliant
processor. Possibly later changed to capture trace from any processor. The
trace has to be modfied to be used by data-acquisition application running
on a PC (interfaces: USB/Ethernet/Firewire)

I figured out that using an FPGA would be ideal for such a application. But
which one ? Any recommendations ? Which processor core to use (Hard/Soft
Core -- cost ??) , IP's for I/O and Nexus. etc

Is anyone working on such a concept/project ?

Pointers and hints and welcome!

Kind Regards,
Ravishankar

On Tue, 26 Jun 2007 11:34:25 +0530, "Ravishankar S"
<[email protected]> wrote:

>Im in embedded software development, but interested in developing a device
>which can caputure trace information from a Nexus class-3 compliant
>processor. Possibly later changed to capture trace from any processor. The
>trace has to be modfied to be used by data-acquisition application running
>on a PC (interfaces: USB/Ethernet/Firewire)
>
>I figured out that using an FPGA would be ideal for such a application. But
>which one ? Any recommendations ?

Unless you expect to embed this functionality in large numbers of
copies of your product, you should instead consider an off-the-shelf
logic analyzer from the usual instrumentation suppliers. You will get
all the functionality you describe, lots of built-in software and
configurability, and a helpdesk to beat-up when things aren't
going well.

Many hobbyists make do-it-yourself logic analyzers based on
some kind of FPGA+PC combination, but it's labour-intensive stuff.
If you need this for your development lab(s), go buy or rent a
ready-to-use box. They're not cheap, but it's well-established
technology and they work brilliantly.
--
Jonathan Bromley, Consultant

DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services

Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
[email protected]
http://www.MYCOMPANY.com

The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.

Hi Jonathan,

But this is a processor with no external bus. (Also its for
experimentation).
So logic analyser as far as I know wont help here. The idea is to build an
emulator which can caputure the Nexus public messages and also write into
internal memories of the controller for calibration of variables.

Kind Regards,
Ravishankar




"Jonathan Bromley" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 26 Jun 2007 11:34:25 +0530, "Ravishankar S"
> <[email protected]> wrote:
>
> >Im in embedded software development, but interested in developing a
device
> >which can caputure trace information from a Nexus class-3 compliant
> >processor. Possibly later changed to capture trace from any processor.
The
> >trace has to be modfied to be used by data-acquisition application
running
> >on a PC (interfaces: USB/Ethernet/Firewire)
> >
> >I figured out that using an FPGA would be ideal for such a application.
But
> >which one ? Any recommendations ?
>
> Unless you expect to embed this functionality in large numbers of
> copies of your product, you should instead consider an off-the-shelf
> logic analyzer from the usual instrumentation suppliers. You will get
> all the functionality you describe, lots of built-in software and
> configurability, and a helpdesk to beat-up when things aren't
> going well.
>
> Many hobbyists make do-it-yourself logic analyzers based on
> some kind of FPGA+PC combination, but it's labour-intensive stuff.
> If you need this for your development lab(s), go buy or rent a
> ready-to-use box. They're not cheap, but it's well-established
> technology and they work brilliantly.
> --
> Jonathan Bromley, Consultant
>
> DOULOS - Developing Design Know-how
> VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
>
> Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
> [email protected]
> http://www.MYCOMPANY.com
>
> The contents of this message may contain personal views which
> are not the views of Doulos Ltd., unless specifically stated.

On Wed, 27 Jun 2007 17:34:43 +0530,
"Ravishankar S" <[email protected]> wrote:

Ravishankar,

>But this is a processor with no external bus.

Ah. Bad assumption by me. I just (foolishly) assumed that
Nexus was yet another regular CPU. Any links I can follow
to take a look?

> (Also its for experimentation).

OK, fair enough.

>So logic analyser as far as I know wont help here. The idea is to build an
>emulator which can caputure the Nexus public messages and also write into
>internal memories of the controller for calibration of variables.

Logic analysers can be persuaded to decode all manner of
protocol stuff, but I agree that this sounds a bit too specialised.

Sorry to have misunderstood.
--
Jonathan Bromley, Consultant

DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services

Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
[email protected]
http://www.MYCOMPANY.com

The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.

Hi Jonathan,

Nexus is a OnChip mechanism which works in conjunction with the debug port
(JTAG). So the debug port controls the device and sets up triggers , the
AUX port send out the trace information and takes in trace data.
More at the Nexus site: can find through google.
One similarity to logic analzysis is the capturing happens synchronous to
the clock: in case of LA its memory clock and Nexus its a special nexus
output clock. The data though in case of Nexus is variable length and is
compressed.


Kind Regards,
Ravishankar




"Jonathan Bromley" <[email protected]> wrote in message
news:[email protected]...
> On Wed, 27 Jun 2007 17:34:43 +0530,
> "Ravishankar S" <[email protected]> wrote:
>
> Ravishankar,
>
> >But this is a processor with no external bus.
>
> Ah. Bad assumption by me. I just (foolishly) assumed that
> Nexus was yet another regular CPU. Any links I can follow
> to take a look?
>
> > (Also its for experimentation).
>
> OK, fair enough.
>
> >So logic analyser as far as I know wont help here. The idea is to build
an
> >emulator which can caputure the Nexus public messages and also write into
> >internal memories of the controller for calibration of variables.
>
> Logic analysers can be persuaded to decode all manner of
> protocol stuff, but I agree that this sounds a bit too specialised.
>
> Sorry to have misunderstood.
> --
> Jonathan Bromley, Consultant
>
> DOULOS - Developing Design Know-how
> VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
>
> Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
> [email protected]
> http://www.MYCOMPANY.com
>
> The contents of this message may contain personal views which
> are not the views of Doulos Ltd., unless specifically stated.