Hello juliana.rojas3062@ctag.com ,
Thanks for the model - I'll take a look and come back with what I find.
Now regarding the RX FIFO, let me briefly walk you through:
The RX FIFO is a queue that holds up to 6 messages; this is helpful if you get them in a very fast succession. When you are enabling the RX FIFO you must be careful not to use certain MBs, as they will be reserved for this functionality. If I remember correctly, MB 0 through 5 are used + additional MBs used for ID Filtering table. The exact number of additional ones will depend on what type of filtering and what filter table you are using. To configure RX FIFO, you'll need to set-up 2 things: the ID format and the filter table. The ID format is telling you how many IDs you'll put per ID Filter table element (those that occupy additional MBs when using RX FIFO)
Format A: One full ID (standard and extended) per ID Filter Table element.
Format B: Two full standard IDs or two partial 14-bit (standard and extended) IDs per ID Filter Table element.
Format C: Four partial 8-bit Standard IDs per ID Filter Table element.
Format D: All frames rejected.
So if you are using format A for example and you are putting 2 IDs in the filter table, you'll be occupying 2 ID FIlter table elements -- this means (if I remember correctly) 2 MBs -- to be sure we should check the S32K Reference Manual.
This works like this: the CPU is repeatedly reading a message buffer structure at the output of the FIFO, so it can read the messages sequentially, in the order they were received.
Kind regards,
Razvan.
