From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: [Socketcan-users] AM335x CAN/D_CAN Date: Tue, 22 May 2012 21:01:06 +0200 Message-ID: <4FBBE272.5020807@grandegger.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from ngcobalt02.manitu.net ([217.11.48.102]:39635 "EHLO ngcobalt02.manitu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755481Ab2EVTBJ (ORCPT ); Tue, 22 May 2012 15:01:09 -0400 In-Reply-To: Sender: linux-can-owner@vger.kernel.org List-ID: To: bruce bushby Cc: Linux-CAN Hello, I switched the discussion to the new Linux-CAN mailing list. On 05/22/2012 05:50 PM, bruce bushby wrote: > Greetings > > I'm hoping a list member would be so kind as to offer some basic > explanations of how one would use the CAN bus provided by AM335x. I > understand Linux, but struggle with electronics. > > I have read this discussion: http://comments.gmane.org/gmane.linux.can/1142 > What is the difference between C_CAN and D_CAN? As I see it, the D_CAN is a more advanced variant of the C_CAN controller. See also: http://www.semiconductors.bosch.de/en/ipmodules/can/canipmodules/c_can/c_can.asp http://www.semiconductors.bosch.de/en/ipmodules/can/canipmodules/d_can/d_can.asp Patches to add D_CAN support to the Linux-CAN C_CAN driver have been posted recently for mainline inclusion and are currently reviewed. > http://www.spinics.net/lists/linux-omap/msg67538.html > Does D_CAN have anything to do with mcp2515? No, nothing apart from the fact that both are CAN controllers. The mcp2515 is connected via SPI bus and from another company. > In order to connect the am335x CAN line to a CAN bus, would I need to > add a CAN transceiver? Hardware-wise, yes. > Is the am335x an "in memory CAN" ... ie I wouldn't need to worry about > SPI bus performance? Right. On the AM335x, the D_CAN controller is integrated into the SOC. There is no SPI involved. > Any explanations and help much appreciated! Hope it's useful. Wolfgang.