We now have the use of i.MX6UL on our products.
According to the Security Reference Manual, low-temperature monitor should assert between -40 and -20 degree.
However we found that some units will start to have the temperature tamper event at -16 degree C.
We've tried the TEMP_LOW_OFFSET bits of DryIce Tamper Offset Control Register (SNVS Expanded_DTOCR), but it makes no different.
And there's another issue about the temperature shown by u-boot.
The CPU temperature is abnormal when the unit is placed in a chamber with temperature below 0 C.
Not sure if the behavior of temperature monitor is related to the wrong temperature.
But it'll be helpful if there is a fix for this.