If you are asking what is the difference between Rev. 1 and Rev. 2 then it is simply that, in Rev. 2, a link (W1) was inserted on the PM0 signal going to the onboard CAN transceiver so that users may isolate this pin from the CAN transceiver. The schematic diagram for Rev. 2 can be found here:
http://support.technologicalarts.ca/docs/NanoCore12/NanoCore12MAX%20(40-pin)/nc12max_sch.pdfIt is not clear from your message what debugger you are referring to. For further assistance, please contact support@technologicalarts.com.
Regards,
Carl