Lpc2000

I know this is off topic, but does anyone have any experience with PC
based scopes like pico? (http://www.picotech.com/oscilloscope.html)
If so, I'd really be interested to hear opinions, issues and/or
considerations.

Thanks,
Bryan
clapper@...

On Thu, 2005-01-06 at 15:29 +0100, b clapper wrote:
> 
> I know this is off topic, but does anyone have any experience with PC
> based scopes like pico? (http://www.picotech.com/oscilloscope.html)
> If so, I'd really be interested to hear opinions, issues and/or
> considerations.
> 
> Thanks,
> Bryan

I have used the pico scope for some uP work; not ARM but what I used it
for might be applicable here (that is to say, on-topic) ;-)

I wanted to determine if a 6309 I was using  would use less power if it
ran with a faster clock rate, finished earlier and then slept waiting
for the next clock interrupt. The 6309 was also running at 100% under
peak load, so I was looking for an excuse to get the clock rate
increased.

I used the pico scope to monitor the voltage and current. It has a handy
feature where you can derive calculated probe values and plot them too;
in my case P = V * I (x factors to create proper units). I also took the
logged values and integrated them for total power consummption. My
measurements showed no value in increasing the clock and sleeping
longer.

One could use a pico scope this way to get a good handle on LPC-based
chip and system power consumption.

I have also used the pico scope to debug a system, monitoring external
audio and control signals (involving a cell phone). The trigger
capability combined with automatic disk logging of the traces made it
possible to run hundreds of tests overnight and debug an infrequent
problem.

The pico scope doesn't have a high sampling rate/bandwidth so I believe
it may not be fully suitable for higher speed logic work. (I have access
to Philips high speed digital scopes that I would normally use for that)
For audio and relatively slower real world events the pico scope has
been useful to me.
-- 
Brett Delmage <BDelmage@...>
JSI Telecom

On 6 Jan 2005 at 15:29, b clapper wrote:

> 
> 
> I know this is off topic, but does anyone have any experience with PC
> based scopes like pico? (http://www.picotech.com/oscilloscope.html) If
> so, I'd really be interested to hear opinions, issues and/or
> considerations.
> 

I have not used the pico scope, but another designed and manufactured in holland.
Before I purchased the unit I looked at quite a number of "PC Scope" spec sheets.
The biggest disadvantage these scopes have compared to more traditional Digital 
scopes are their trigger circuits. The trigger circuits of a typical modern digital scope 
are orders of magnitudes more advanced than the circuits on the PC Scopes. It seems
that most of them capture the data via the A/D circuit and then do a software "trigger"
on the data. This is not fast or consistant enough to trigger on glitches etc.

Regards
  Anton Erasmus


-- 
A J Erasmus