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CAN Module: Extended ID?

Question asked by gpetrowitsch on Oct 26, 2010
Latest reply on Nov 9, 2010 by jobo23

Hi,

 

I'm a bit confused with respect to the Extended ID register fields

in the Blackfin CAN module (BF548).

The documentation lists 3 fields in figure 27-3 - the BASEID, the

EXTID_LO and the EXTID_HI. But when I look at the register

description EXTID_LO are bits [17..16] of the extended ID while

EXTID_HI are bits [15..0].

Shouldn't the field with the higher bit numbers be called _HI ?

Or does this imply any kind of reverse bit ordering ???

 

If you don't understand, what I'm talking about, perhaps you can

answer this question:

If I have a 29 bit extended CAN ID - let's name it ID[28..0] - is it

then correct to do this assignment (for a transmit mailbox)

BASEID = ID[10..0]

EXTID_HI = ID[26..11]

EXTID_LO = ID[28..27]

?

 

Thanks and regards,

Gerhard

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