CAN and USB sharing the same lines

russ · ‎2008-06-12

Posted on June 12, 2008 at 23:20

russ · ‎2011-05-17

Posted on May 17, 2011 at 12:37

Is it possible to have CAN and USB share the same lines to allow switching between both protocols? (They go to the same pins on the chip) I know USB requires transient voltage supression circuitry (like the USB6B1:

http://www.mouser.com/Search/ProductDetail.aspx?qs=f9uBznyCLhZlkTGf%252b8M7Kg%3d%3d

)

Will this interfere with CAN? I wouldn't think so. I also have seen that CAN communication requires its own seperate transceiver. Is this an absolute necessity?

What I am trying to do is allow USB programming via bootloader, then CAN communication to external devices on the same outputs (over a USB cable).

Any advice/input is much appreciated.

jj · ‎2011-05-17

Posted on May 17, 2011 at 12:37

Suspect someone here knows - will advise.

In absence of ''tried/proven'' how about using ''2-wide'' data mux -

steering STM32 pins to either USB or CAN bus components?