Voltage status and control

[Ars_]

Hello NXP Team,

How shall the flags of LVSC register in S32K388 be interpreted 

Go/NoGo flags 

  Are they indicators of the power supplies to clock circuits only?

  What is the recommended safety measure for these flags

LVDx and LVRx

  How shall LVDx be interpreted. How does it differs to LVRx flags? Won't the level drop below threshold results in reset ?

 What is the recommended safety measure for LVDx flags

[danielmartynek]

Hello @Ars_,

Q: Are they indicators of the power supplies to clock circuits only?
A: Yes
Q: What is the recommended safety measure for these flags?
A: Refer to S32K3xx_fault_map.xlsx attached to the Reference Manual.
Recommended recovery mechanism: interrupt followed by SBC‑initiated POR triggered from the ISR.
Q: How shall LVDx be interpreted? How does it differ from LVRx flags? Won’t dropping below threshold cause a reset?
A: LVD monitors are not a source of system reset. LVR triggers the reset.

Refer to S32K3xx Datasheet, Table 10 (Supply Monitoring) for threshold values.

Q: What is the recommended safety measure for LVDx flags?
A: LVD thresholds are within the operational range and act only as warning indicators. SW reaction via interrupt.

Also, refer to the S32K3xx Safety Manual available in S32K3xx Secure Files under an NDA.

Regards,

Daniel

[Ars_]

Hello Daniel,

Thanks for the inputs. Could you please clarify below points too

I am a bit confused about the S32K3xx_fault_map.xlsx NCF[4].

It says 'Voltage related errors: PMC 1.1V and 2.5V GnG;PAD overvoltage'

Does it mean just the below flags are routed to FCCU

      PMC 1.1 - LVR11LPF, HVD11S

      GNG 2.5 - GNG25OSC2F, GNG25OSCF

There are two LVR flags given for a particular supply for ex. LVR25LPF and LVR25F. How are they different to each other.

[danielmartynek]

Hi @Ars_,

Only these faults are routed to the FCCU:

• VDD2P5_GNG_ERR
• VDD1P1_GNG_ERR

The following faults are routed to the Reset Generation Module (MC_RGM):

• LVR11
• LVR25

LVR25F indicates that a low-voltage reset event has occurred on the V25 power domain in FPM (Full Performance mode / RUN mode).
LVR25LPF indicates that a low-voltage reset event has occurred on the V25 power domain in either FPM or LPM (Low Performance mode / Standby).

Regards,

Daniel