TMS320F28035: CAN Bus Network

user4997907

Part Number: TMS320F28035

I'm trying to understand how the CANBUS works on the TMS320F28035 and I can't seem to get a handle on it.

Can the CANBUS be used to receive any message or are the mailboxes only allowed to target specific messages and to extend this range you mask the bits?

Also is there a way to view exactly what the CAN Identifier is?

Thanks,

Christian

over 7 years ago

0 Hareesh Janakiraman over 7 years ago

TI__Guru* 95315 points

Christian,

When a receive MBX is configured with a MSGID and no acceptance filtering is used, that MBX can only receive frames with that exact MSGID.

When a receive MBX is configured with a MSGID and acceptance filtering is used to mask some bits of the MSGID, that MBX can receive frames that satisfy the filtering criterion.

When a receive MBX is configured with a MSGID and acceptance filtering is used to mask all bits of the MSGID, that MBX can receive frames with any MSGID.

You would benefit from downloading my app.note SPRA876 from www.ti.com and taking a look at the example CAN_LAM. That example clearly illustrates how acceptance filtering works.

0 Hareesh Janakiraman over 7 years ago in reply to Hareesh Janakiraman

TI__Guru* 95315 points

Also is there a way to view exactly what the CAN Identifier is?

Answer--> Yes, you just read it off the MSGID field in the mailbox RAM

0 user4997907 over 7 years ago in reply to Hareesh Janakiraman

Intellectual 270 points

Thanks for the speedy reply Hareesh! I've looked through and I can't find where the LAM registers would be for this model. I did find the GAM registers in the ECanaRegs Struct. Can I use the GAM field instead? The MSGID I read in the mailbox RAM is the value i previously set though

0 user4997907 over 7 years ago in reply to user4997907

Intellectual 270 points

Nevermind, found them and it's working now! Thanks!

0 Hareesh Janakiraman over 7 years ago in reply to user4997907

TI__Guru* 95315 points

Glad you resolved it. Please close the post.

(The LAM registers are part of the ECanaLAMRegs Struct. Advantage of using LAM: You get a separate mask for each one of the 32 mailboxes)

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TMS320F28035: CAN Bus Network