CAN bus module

[Altera_Forum]

IIRC Nios II does not provide a CAN bus module by default. What are the choices if you want to add CAN support to your Nios II design? 

Is it possible to integrate the OpenCores CAN controller to NIOS or do I have to buy some expensive IP by a third-party vendor?  TIA, Markus

[Altera_Forum]

Opencores can works fine. Don't forget the legal issues with CAN bus for commersial products.  

 See opencorecanproject (http://www.niosforum.com/pages/project_details.php?p_id=46&t_id=18).  Stefaan

[Altera_Forum]

Oops, don't know how I overlooked that one. Thanks for the link. Unfortunately I always get a blank file when downloading it from the project page. However, I was able to download the file from the corresponding thread in the forum. 

 Yeah, I'm aware of Bosch's CAN Protocol License. I will evaluate both methods the OpenCore and a SJA1000 version.  Thanks again, Markus

[Altera_Forum]

--- Quote Start ---  originally posted by dafox@Sep 19 2006, 08:59 AM oops, don&#39;t know how i overlooked that one. thanks for the link. unfortunately i always get a blank file when downloading it from the project page. however, i was able to download the file from the corresponding thread in the forum.  yeah, i&#39;m aware of bosch&#39;s can protocol license. i will evaluate both methods the opencore and a sja1000 version.  thanks again, markus <div align='right'><{post_snapback}> (index.php?act=findpost&pid=18330)  --- quote end ---    --- Quote End ---    The Opencore version looks quite the same as the SJA1000 with respect of the bus interface. But with the 32 bit capability of NIOS and because all signals are internal the fpga, with little effort you can change the registers a little bit to get faster access. This can be importand to reduce interrupt time ar receiption of messages.

[Altera_Forum]

--- Quote Start ---  originally posted by svhb@Sep 21 2006, 07:54 AM the opencore version looks quite the same as the sja1000 with respect of the bus interface. but with the 32 bit capability of nios and because all signals are internal the fpga, with little effort you can change the registers a little bit to get faster access. this can be importand to reduce interrupt time ar receiption of messages.  --- Quote End ---    Yep, unfortunately this is the trade-off I have to live with to avoid Bosch&#39;s CAN protocol license.  Markus

[Altera_Forum]

I believe it&#39;s not so expensive, but they do big volumes. When I asked for a quote, it was around 10.000euro for 100.000 can controllers (around 0.10euro/piece). 

 So if you have enough volume, and space available in the fpga it is cheaper. If the volume is low (this is the case for most fpga designs I think) or you have to go to the next bigger device because of the can bus, I think the SJA1000 is cheaper (but o so slow tointerface).

[Altera_Forum]

Hi,DaFox. Could you please send me the "opencorecanproject" mentioned by svhb? The website is unavailable now. Thank you. Lucius

[Altera_Forum]

The Opencores site is at this address: http://opencores.org and I guess that the CAN project they are talking about is this one (http://opencores.org/project,can)