Hi,
i have the need to monitor a lot a CAN IDs. Is this possible with the can Stack of the FSP Configuration.
I have the need to check the can message regardless which CAN Identifier is used. Therefore I can not assign a CAN ID to the mailboxes.
Thanks Michael
Do you know the numbers of the IDs you want to monitor? Are they in a convenient group, or spread all over the place? Are there IDs that you want to ignore?
The acceptance filtering is pretty smart, for instance, if you want to monitor 256 IDs starting at a certain number then you can route them all to ne mailbox using the filters.
Never knew that. Is that kind of filtering built into the HW?
Larry
Yes.
If you set the bit in the MASK INVALID register, then the mailbox only accepts messages where the message ID matches the number in the ID register.
The same thing happens if you set the mask to 0x1FFFFFFF and clear the bit in the MASK INVALID register.
This is where it gets clever. If you set the mask to 0x1FFFFF00, and put 0x12345600 in the ID register then it will accept all messages from 0x12345600 to 0x123456FF, and the actual number of the ID of the message will be put in the ID register, so you can read it to find the ID of the message.
The snag is that there are only 8 Mask registers, NOT one for each mailbox, so you have to be quite strategic how you use the mailboxes.