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FlexRay on MPC5748G - Basics implementation

Question asked by Jonathan L on May 28, 2018
Latest reply on Aug 3, 2020 by Yiming Cheng



I'm trying to write a very basic FlexRay Test code, actually for the moment just to test hardware. There is no OS.


I have some questions about basic stuff :

  1. how can I determine the System Memory Base Address Register (FR_SYMBADR). I mean how to "choose" this address and assure that there is not conflict with other part of code. Because this choosen address will be in a register but not "reserved" by the code. Is it absolutely mandatory to map this address with a structure ?
  2. I understand that the data field part of physical message buffer is linked to the header part via the data field offset (FR_MBDOR). But these data field offset has to be calculated by the application in order to fill FR_MBDOR. Actually, based on the reference manual reading I don't understand how to calculate them. Could you give a example with 2 messages buffers ?
  3. I don't understand the purpose of the message buffer segment feature ( FR_MBDSR[MBSEG1DS]  and FR_MBDSR[MBSEG2DS]).
    I'm beginner with FlexRay. This is the reason of so basics questions.

Thanks in advance.