Harjit Singh wrote:
[...]
> The reason a serial debugger is prefered to a BDM based debugger is
> that I'm doing some robotics work and I can make the servo code run
> at a higher interrupt level than the serial debugger and this will
> allow me to debug code with servos running.
>
> BDM is too intrusive and it will cause the servos to go nuts.
In most cases, a serial debugger will have more impact.
Do you want single step debugging of one task while the interrupt
service routine is still running? This might indeed be harder.
If you only want to observe or maniplate variables during program
execution, BDM is likely the better way.
> The CF debug docs say that BDM theoretically will steal cycles but
> everything I have read says tha the BDM debuggers halt the CPU...
Coldfire V2 BDM is indeed more intrusive than the HC12 BDM is.
Accessing memory stalls the pipeline, causing several cycles delay. I
couldn't get Freescale giving me official numbers, but my
measurements showed me that 4..6 cycles for every memory access are
likely.
You will probably see such delays also when using DMA transfers.
With architectures like the Coldfire V2, you shouldn't rely on
precise cycle by cycle instruction timing unless you know very well
what happens.
Oliver
--
Oliver Betz, Muenchen
---
coldfire@... Send a post to the list.
coldfire-join@... Join the list.
coldfire-digest@... Join the list in digest mode.
coldfire-leave@... Leave the list.
