CAN filter

[Yannick Dannel]

Posted on February 06, 2018 at 14:44

Dear,

I try to understand CAN filtering mechanism  to use it in my application. I understand that it is possible to filtering by ID type, frame type and ID scale.

In the case of standard ID, I understand that it's possible to filtering on all bits off the ID. But for the extended ID, I only see EXID[17:0] (32 bits filter) and EXID[17:15] (16 bits filter).

It means it is impossible to filtering on the MSB bits of the extended ID (EXID[28:18]) ? Or this MSB is on STID[10:0] in the case of extended ID ?

Regards,

[Ben K]

Posted on February 08, 2018 at 11:11

If you consider how the extended ID appears in the CAN frame the answer is clear: the MSB 11 bits are the standard ID, then the remaining 18 bits come after the extended ID flag.