We are using a imx6ul and want to enable tamper functions s.t. ZMK and LPGPR will be deleted in case of a tamper event. Unfortunately active tamper functions as well as temperature tamper functions are not working at all.
*) Device is in "Trusted"-State (HAB enabled and device closed)
*) LPPGDR was set and PGD cleared in LPSR as described in Section "Power glitch detector"
*) SRTC is enabled (LPSRTCLR is counting)
*) LPGPR0 is set to a known value
For active tamper functions:
*) ATx_PAD_EN and ATx_EN is enabled in LPATCTLR (for all x = 1 to 5)
*) but we could not measure any output of the LFSR at the Tamper-Pins using a oscilloscope
For temperature tamper functions:
*) DRYICE_EN is set in DTOCR
*) TEMP_DET_EN is set in DMCR
*) TT_EN is set in LPTDCR
*) when the device is cooled below -30°C the tampering is still not detected. (LPGPR0 is not cleared, State not changed, no Flag in LPSR)
Are we missing anything? - Any help would be appreciated!