Re: Receiving CAN messages with TouCAN

The Philips SJA1000 CAN controller chip is unusual in that it has a 
small on-chip FIFO that will hold any packet that matches any 
filter/mask combination.  I seem to recall that it would hold around 
8-16 packets.

The TI DSP TMS320F2812 has an "eCAN" peripheral with a feature that 
allows a recieved packet to keep "rolling over" full mailboxes until 
it finds one where the filter/mask match, AND the mailbox is not full 
yet.  Since there are 32 mailboxes, that's a nice feature.

Still, I would always use interrupts.

Rick Corey

--- In [email protected], "Randall Young" <ryoung@...> wrote:
>
> 
> 
> > By the description
> > of the controller, it should be possible to set several message
> > buffers to read mode. If
> > a message arrives it sould be placed in one of the empty buffers
> > until all buffers are filled.
> 
> My experience was that it does not work this way.  Multiple read 
buffers are
> only effective if you can use the mask to sort the messages out 
(which isn't
> likely).  An incoming message always goes to the first buffer whose 
mask
> will allow it.  If that buffer is full, the message is lost even if 
other
> buffers would accept it.
> 
> Randall Young
> Senior Software Engineer
> NavCom Technology, Inc.
> A John Deere Company
><-- snip -->






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