Mark Butcher

Coldfire: FlexCAN - where are the buffers hiding??

Discussion created by Mark Butcher on Jun 9, 2006
Latest reply on Sep 29, 2006 by Mark Butcher
Hi All
 
I am making my first attempts with the FlexCAN in the M5213.
 
I wrote the initialisation sequence according to the data sheet and loaded it to the EVB and looked at the registers.
 
The initialisation seemed OK - the registers had the expected states with no error flags set.
 
But where are the message buffers? I have the registers at 0x401c0000 but no signs of buffers. I thought they should be 0x80 offset from the start of the CAN block - 0x401c0080 - but the CodeWarrior with Multilink BDM is displaying this area as non-accessible so I can neither see contents nor write anything.

Is this a debugger issue or a setup issue?
 
I have read through the data sheet a couple of times but don't find anything about having to activate the buffers or similar.
 
Any ideas?
 
Best regards
 
MarkButcher
www.mjbc.ch

PS. I tried sending a message in loop back mode (working blind by copying the contents of the message buffers to an array which I can see in the debugger) and it seems as though it really arrives - this suggests that they are there in the correct place but the debugger is doing something strange... (???). I also have a M52235EVB with the same CAN  - maybe it will respond differently - I will check tomorrow if I find the time...

Message Edited by CrasyCat on 2007-04-13 01:50 PM

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