PMS_AG21_STDBY=0 or 1 for SAK-TC387TP when all external power supplies are used

[User9635]

Hello Support,
In a Pristine SAK-TC387TP device from Infineon without any Flash Image content being present within the device, is it guaranteed ALM21[0]=0 [ Same as PMS_AG21_STDBY[0] =0] assuming all external Power Supply to the device is perfectly matching the Datasheet Specification.
Assume all Power Supply are being supplied externally instead of any of the internal voltage regulators.

Best Regards,

[NeMa_4793301]

Please check EVRADCSTAT.UVC: that corresponds to the mechanism that sets ALM21[0] (hoping that link gets fixed in the next iteration of documentation). If that's set, then look for high frequency noise on 1V25 that may be causing the alarm. Use an active probe if possible.

[User9635]

Hello Support,

For BGA-292 SAK-TC397 Aurix device, Ball G17 is PORST_N signal.
Will activating [pulling down] PORST_N signal clear this PMS_AG21_STDBY Register contents to zero?
During Cold Power On, will this PMS_AG21_STDBY register bits get set/fault before PORST_N signal is deactivated [pulled high] if any external supply are beyond spec due to noise/glitch?

Best Regards

[NeMa_4793301]

Per Table 523 on page 1289 of AURIXTC3XX_um_part1_v1.4.pdf: an external power-on reset resets the SMU (clearing all alarms).

Your application should clear supply related alarms at startup, based on this section from the user manual:

11.2.2.5.2 Secondary over- and under-voltage monitors and alarm generation
After start-up, it may happen that supply over- or under-voltage alarms may already have been triggered depending on residual start-up voltages or supply dynamics.