TCAN4550-Q1: Inquiry regarding CAN FD

Hi Terry,

The number of CAN messages that you can receive and hold in the TCAN4550-Q1's Memory RAM (MRAM) will depend on how you allocate the memory and how many RX FIFO/Buffer elements you create.

The TCAN4550-Q1 has 2kb of total MRAM space that is used for the 11-bit SID Filters, 29-bit XID Filters, RX FIFO 0, RX FIFO 1, RX Buffers (dedicated), TX Event FIFO and TX Buffers.

The amount of actual memory that each RX and TX Buffer element requires will also depend on how may data bytes you need to store the message with the largest data payload.  For example if you need to receive a message that has 64 bytes, then all RX buffer elements will need to have 64 data bytes reserved.  But if you only needed 8 bytes, then you would only need to reserve 8 data bytes for each buffer.

Each RX FIFO (0 and 1) can have up to 64 elements created, and there can also be up to 64 dedicated RX Buffer elements as well.  This is the maximum number of elements that the Bosch MCAN IP can support from a configuration perspective.  However, the total available MRAM space that must be shared with the other element types may be a limiting factor for your application.  But technically speaking there could be up to 192 RX message memory elements allocated if size permits.

You can find more MCAN specific information including the allocation of the MRAM in the MCAN User's Manual published by Bosch. (Link)

Let me know if you have any additional questions.

Regards,

Jonathan