CAN gateway

We recently started developing some CANbus routines using the R8C/23 with the E8a tool and were at that time planning to interface CAN<>UART.

However a change means we are now looking to create a more pure CAN gateway to interface 2 can busses ie: CAN<>CAN, we invisage the gateway would decode and pass selective commands between the two busses... we don't need a high pin count, and would be looking for a low cost part. The bus on one side would run at 125K and the other at various speeds below that.

If any of you wise gentlemen have any suggested parts that I may take a look at I am all ears, none of the R8C have 2 can channels so I am unsure in which family direction to traverse.
Thanks & Regards


  • Hi Connel,

    The best solution will be the R32C/118.  The smallest package with 2 channels of CAN is currently a 100 pin package and both the M16C/6N and the R32C/118 is available in these packages.  However the pricing of the R32C is almost half that of the M16C/6N, so this will be the best solution to look at.



  • Hi Marinus,

    Thks for the comments, I will take a look at those parts. It just seems such overkill to add a large part to accomplish this, I imagined it would be a fairly common requirement.

    Would it be worth investigating using something like a SJA1000 or dare I say an MCP2515.. I guess it is not really worth it due to the added hassels it would add trying to tie it all together, but potentially could connect the MCP2515 via SPI to the R8C/23.

  • Hi Connel,

    I always tell people that there is always a couple of options to consider that will meet your requirements, but the final decision lies with you.

    The MCP2515 in combination with the R8C/23 looks like the best option at this stage though.

    Interesting enough is that a lot of people are looking for a 8/16 bit small pin count device with 2 channels of CAN and it is not commonly available from microcontroller manufacturers, but I think it should soon be available due to the demand lately.  Most microcontroller manufacturers can only offer a large pin count 32 bit device for this requirement.

    Good luck with your project.



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