[En-Nut-Discussion] Forward of moderated message: AT90CAN128

[Henrik Maier]

Hello Roberto,

First question:

The Nut/OS port to the AT90CAN128 chip has come to a sudden stop a week 
ago when we discovered stability problems. I am still investigating the 
exact cause of the issue but can conclude:

- The issue relates to using the AT90CAN128 instead of ATmega128 on the 
same hardware.
- We tested different boards, our own industrialised XNUT-100 board and 
an Ethernut 1.3f board reworked with a AT90CAN128 CPU.
- The issue relates to external RAM
- The issue does not relate to the tool chain or Nut/OS version. I 
tested WinAVR 2004 and the latest WinAVR 2005 as well as Imagecraft with 
3.4.2, 3.9.1 and CVS head of Nut/OS.
- Our current believe is that the issue relates to stack operations 
(push/pop) in external RAM. Normal load/store operation seem to be ok. 
But this needs further investigation to be confirmed.

Simple programs, basemon's tests and in particular it's RAM test, all 
work fine as long as the threads are allocated in internal memory. Once 
threads are allocated in external memory then the system will crash 
after a short period of operation.

At this stage the combination of Nut/OS, Ethernut compatible hardware 
and the AT90CAN128 CPU cannot be considered to run stable. At least not 
on my lab bench.

The issue might not even relate to Nut/OS itself but to the CPU core or 
the CPU requiring a different XRAM interface.


Second question:

I am sure that there will be several vendors offering AT90CAN128 boards 
in the future, one of them is the company I am working for. A plain 
Ethernut board would not be sufficient as you need a CAN transceiver 
chip on board as well.

Regards

Henrik
-- 
FOCUS Software Engineering Pty Ltd
Brisbane, Australia - Web: www.focus-sw.com
Phone: +61-402 970 933 - Fax: +61-7-3009 0399

en-nut-announce-bounces at egnite.de wrote:
> 
> ------------------------------------------------------------------------
> 
> Subject:
> AT90CAN128 again.
> From:
> roberto.bacenetti at lombardiacom.it
> 
> Hello,
> I followed the thread about AT90CAN128 in the discussion faq.
> A NutOS version for the chip is available.
> Is there a plan to sell AT90CAN128 equipped boards as well ?
> 
> Roberto
>