Bosch - MPC5746B - Overview about Safety Measures to reach ASIL B

[jochengerster]

Hi

MPC5746B (Calypso3M) shall be used in a commercial vehicles projects by Bosch.

Target is ASIL-B

Bosch already had a look at the SM documentation and wonder how they shall perform Reciprocal Cross-Check (SW lockstep) on a single core device?

Beside this the question came up is such a redundancy required for an ASIL-B ?

Last point, can we share an overview list with the typical SMs, which are required to reach ASIL-B?

thanks

Jochen

[jochengerster]

It seems safety is a quite new topic for the Bosch commercial vehicle guys

The question is what SM shall be implemented....

Would it be possible to have a short call with them to get them up to speed ?

thanks

[aarul]

Hi Jochen

1. Reciprocal comparison requires at least two cores and so cannot be performed in a single core system. For a single core system, the user can make use of temporal redundancy to cover for transient failures. For detecting permanent faults, the user can use software based self-test.

2. Usually SCST is sufficient for ASIL B coverage over permanent faults. If the user wants to cover transient faults they can use temporal redundancy. 

3. The FMEDA has the safety mechanisms that can be selected/de-selected to allow reaching ASIL-B coverage.

Regards

-Aarul

[jochengerster]

Thanks Aarul for your reply

Where can I found the latest FMEDA for this device?

The one I have on my PC are quite old...

PS: The generated sheets can still be shared with customer, as an example right?

best regards

Jochen

[nxf65498]

Hi Jochen,

Latest FMEDA are available on internal share-point website, which you can configure it according to customers inputs and generate static FMEDA. The static FMEDA can be shared with customer via docstore if NDA is available.

I hope it answers your concerns.

Best regards,

Bhavik