topic imx8mq CPU Temperature in i.MX Processors

imx8mq CPU Temperature

bineyamtafesse — Wed, 03 Apr 2019 21:53:29 GMT

I am running the following configuratoin
CPU: imx8mq (custom PCB)

Linux OS: Linux 4.9.123

I noticed the TMU generated temperature exceeded warnings and cutoff on power up. The critical temperature limit of 95C was tripped (the processors were nowhere near this temperature). I modified the trip-temperature to 125C and the device boots through u-boot and kernel and functions as intended (and has been working for weeks). Now, increasing the temperature is a temporary solution. What is the expectation in terms of calibration? I see there is a definition in the u-boot under "tmu" that looks like a calibration table. Is the expectation that we calibrate every unit?

Re: imx8mq CPU Temperature

weidong_sun — Wed, 17 Apr 2019 08:12:33 GMT

Hello bineyam，

For i.mx8MQ application, the better choice is to use a heatsink according to real application.

In addition, The limit temperature of die is 125 degrees Celsius. So, you can't configure the temperature to exceed 125 degrees Celsius. Probably 115 degrees Celsius can meet your requirement.

Have a nice day!

NXP TIC team

Re: imx8mq CPU Temperature

bineyamtafesse — Fri, 19 Apr 2019 20:17:43 GMT

Hi weidong.sun‌,

The issue is that on immediate power-on (from room temperature), the u-boot reads 112 Celsius. Clearly, the chip is not heating up to 112C in less than 10 seconds while only pulling 2W. This is why I'm asking if additional calibration is needed.

Re: imx8mq CPU Temperature

jming — Mon, 14 Jun 2021 01:58:57 GMT

Hi @bineyamtafesse

My IMX8M custom board has the similar issue, Have you fixed the issue or not ?

Thanks.