S32K3 Safety Measure ID 1855314 M7 speculative access

[jinjingyang]

Hello, Sir,

In S32K3xx safety manual attachment "Addendum_S32K3xx.xlsx", there is a safety assumption for S32K3x4. The safety assumption ID is 1855314.

It says "Side-effects of speculative accesses by the M7 processor core on the correct system behavior are inhibited or prevented to occur."
Could you please explain how to prevent the speculative access by M7 processor core?

Regards,
Jason Yang

[nxf55526 · Accepted solution]

Hello Jason,

The section '5.5.5 Arm Cortex-M7 speculative accesses' in the S32K3XX_SM_Rev1 explains the intent for having this assumption of use. The best detailed reference for this is the Arm Cortex-M7 Processor Technical Reference Manual (link for this is there in section 5.1.2 of the S32K3xx RM). Section '5.2 Speculative accesses’ in the S32K3xx RM is the best overview we have for this. Hope this answers. 

Kind Regards,

Avni