Flexray example code queries

Paul Bremner

I am running the 5 nodes flexray demo source code for CCSv5.x on the TMS570LS MDK, and while it is running fine I have a number of questions regarding some the register settings:

8 static frames defined when there are only 5 nodes.
Over long static frame length of 86 macroticks - for the defined payload the required time is 26 MacroTicks (by my calculations).
Under filled static frame - frame payload is 18 bytes, but only 8 bytes are filled (similarly for the dynamic frames).
Over long symbol window - the typical example in the Flexray protocol specification gives a symbol window of 138 MacroTicks, 714 are defined in the example.
Over long network idle time - the Flexray protocol specifies an idle time of 2-805 MacroTicks, 2814 are defined in the example. Further, the calculated NIT start in the comments gives an NIT start of 0xAE3, but 0x578 is set to the register, effectively starting the NIT in the middle of the dynamic segment.
The defined offset correction start far exceeds the criteria - in the comments the calculation for the OCS gives a value of 0xAE4 which is then defined in the register, but the NIT value in the register is only 0x578.

Each of these points is basically needing to know why you have done them. As there is no readme file with the example it is hard to figure out your design decisions. A readme file specifying the parameters of the network, and what the example will do would have been very useful.

Cheers,

Paul Bremner

over 12 years ago

0 Chuck Davenport over 12 years ago

TI__Guru 59540 points

Hello Paul,

I have forwarded your questions to our Flexray expert and they should get back with you shortly.

0 A Arora over 12 years ago in reply to Chuck Davenport

TI__Mastermind 30845 points

Paul,

I am not quite sure why the code is configuring settings out of the allowed range. But as such I wouldn't read too much into this example code as this may partly be an out of date example. I have filed a request for an update to this example code.

Regards,

Abhishek

0 Jaasiel Walter over 7 years ago in reply to A Arora

Prodigy 20 points

Dear TI Community Members,

I am concerned with the same question and I searched for new examples, but there are still only these examples available, where the network idle time is far too big (should be a maximum of 805 MT).
Could you please tell me, if there is a new example or much better, why the example parameter set is working (which in fact should not be possible with regard to the FlexRay Protocol Specification V2.1 Rev. A)?

Thanks and regards,
Jaasiel

0 Charles Tsai over 7 years ago in reply to Jaasiel Walter

TI__Guru**** 176296 points

Hi Jaasiel,

The example I can find is here. If you already have this example, then there is no other example that I'm aware of. Below two posts might be also helpful.

0 Jaasiel Walter over 7 years ago in reply to Charles Tsai

Prodigy 20 points

Hello Charles,

thank you very much for the example. Unfortunately, this is the example I used to test the communication.
Do you know, why the FlexRay-communication is working, despite there are non-conformant (NIT, Symbol Window) parameters defined?

Thanks and regards,
Jaasiel

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Flexray example code queries