TMS570LS3137: FlexRay Message Data Reading Issue Due to MPU Configuration

Ceyhun Deniz

Part Number: TMS570LS3137
Other Parts Discussed in Thread: HALCOGEN

Tool/software:

Hello,

I am communicating between MCUs using FlexRay. In my project, I am also using the FTU module. When I call the "_mpu_init()" function in the project, I am unable to read the data correctly. In the HALCOGen settings under "R4-MPU-PMU," when I set the "Type" option of the region corresponding to "0xFF00 0000 - 0xFFFF FFFF" to "STRONGLYORDERED_SHAREABLE" and the "Permission" option to "PRIV_RW_USER_RW_NOEXEC," I am able to read the data correctly. Other "Type" options do not work. What is the reason for this?

6 months ago

0 jagadish gundavarapu 6 months ago

TI__Guru 69891 points

Hi Ceyhun,

Can you please refer below FAQ related to MPU configurations once:

(22) [FAQ] TMS570LC4357: What are the differences among the memory attributes, memory types and cache policy in MPU settings? - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Here my colleague explained about different configurations related to MPU in detailed.

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Thanks & regards,
Jagadish.

0 Ceyhun Deniz 5 months ago in reply to jagadish gundavarapu

Prodigy 10 points

Hi Jagadish,

I reviewed the post you sent and I understand it, thank you for that. However, why do I specifically need to work with 'STRONGLYORDERED_SHAREABLE' in FlexRay? Why is it necessary to guarantee that memory accesses are performed in a strict order?

0 jagadish gundavarapu 5 months ago in reply to Ceyhun Deniz

TI__Guru 69891 points

Hi Ceyhun,

I never face this issue in FlexRay because i didn't use the FlexRay much, however i am suspecting this:

FlexRay involves strict timing constraints,

If the memory region is not configured as strongly ordered, the CPU might reorder or delay the memory accesses and this leading to incorrect or stale data reads. Here STRONGLYORDERED_SHAREABLE ensures that all the access happen in the order they were issued, preventing inconsistences.

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Thanks & regards,
Jagadish.

0 Ceyhun Deniz 5 months ago in reply to jagadish gundavarapu

Prodigy 10 points

Hi Jagadish,

Thank you very much for the information. I will take what you said into consideration. Have a nice day.