Lpc2000

Hello All,

although I'm currently not using LPC21xx, I consider it as an upgrade 
path from the Motoro^W Freescale MC9S12. So please excuse if I ask 
something widely known - as a novice I might have overlooked the 
right document.

Can I access memory while the program is executing (like via BDM in 
the 68HC(S)12), whithout noticeable influence on program execution?

Or does a memory read always interrupt program execution for many 
cycles?

If "non intrusive" is possible: is this a standard feature of 
debuggers?

Can I also write memory this way?

Any general hints about good debuggers?

Links to web sites about this topic also welcome.

Thanks in advance,

Oliver
-- 
Oliver Betz, Muenchen

Hi Oliver,

since your last post I learned something new about debugging. The
Philips implementations of the ARM micros include something called
Real-Time-Monitor, a ROM monitor that comes from ARM and will be
(better) supported by an upcoming release of the ARM toolchain. As
always, it is a matter of tool support but the firmware in the
microncontroller exists to do background debugging similar or a little
better than on the Motorola chips without using the Trace feature
(which costs quite some extra pins but provides Code trace without ANY
real-time conflicts). 

There is a lot of information about ARM debugging here:
http://www.arm.com/pdfs/DUI0118C_TDT_1_2.pdf

but it is a large file, about 2 MB!  

Cheers, Bob

--- In lpc2000@yahoogroups.com, "Oliver Betz" <list_ob@g...> wrote:

> Hello All,
> 
> although I'm currently not using LPC21xx, I consider it as an upgrade 
> path from the Motoro^W Freescale MC9S12. So please excuse if I ask 
> something widely known - as a novice I might have overlooked the 
> right document.
> 
> Can I access memory while the program is executing (like via BDM in 
> the 68HC(S)12), whithout noticeable influence on program execution?
> 
> Or does a memory read always interrupt program execution for many 
> cycles?
> 
> If "non intrusive" is possible: is this a standard feature of 
> debuggers?
> 
> Can I also write memory this way?
> 
> Any general hints about good debuggers?
> 
> Links to web sites about this topic also welcome.
> 
> Thanks in advance,
> 
> Oliver
> -- 
> Oliver Betz, Muenchen

lpc2100_fan <lpc2000@yahoogroups.com> wrote:

> since your last post I learned something new about debugging. The
> Philips implementations of the ARM micros include something called
> Real-Time-Monitor, a ROM monitor that comes from ARM and will be

in the PDF document you mentioned, I only found the term 
"RealMonitor": "RealMonitor is a component of ADS, and requires 
either Multi-ICE Version 2.0 or ARM ADI". It "uses the target 
processor DCC channel" and needs "RMTarget" software running on the 
ARM7 (I guess using standard IRQ from DCC).

I found no spec about the CPU cycles needed to transfer one word from 
or to target memory - any hint where to look?

Anyway, that's _not_ like Motorola BDM, where unused bus cycles are 
used to access target memory. BDM is handled by a piece of hardware 
in the uC and doesn't require RAM, ROM or CPU cycles.

In (some of) my applications, I have code portions where the precise 
timing is essential (e.g. integrating an analog signal over a 2us 
period). If some debug firmware runs hundreds of nanoseconds or even 
longer, the device doesn't work as intended.

> (better) supported by an upcoming release of the ARM toolchain. As
> always, it is a matter of tool support but the firmware in the
> microncontroller exists to do background debugging similar or a little
> better than on the Motorola chips without using the Trace feature
> (which costs quite some extra pins but provides Code trace without ANY
> real-time conflicts). 

I don't see the advantage over the Motorola solution, maybe I missed 
something?

Can I read memory via ETM during program execution?

BTW: there is also a (small) trace buffer in newer HCS12 derivatives.

Oliver
-- 
Oliver Betz, Muenchen