Understanding CPU-therm from /sys/class/thermal/thermal_zone1/temp in Jetson Nano

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
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I am using Jetson Nano and L4T32.74. In the table for topic “Thermal Specifications” , CPU-therm is shown for the CPU.

In the software, this is mapping to cat /sys/class/thermal/thermal_zone1/temp. So this a a thermal zone temperature for the CPU.

Query:
There are four ARM cores in Jestson Nano and in the Section “40.3 Thermal Sensing (SOC_THERM_tsense)” of Tegra_X1_TRM_DP07225001_v1.3p.pdf it is mentioned that: “SOC_THERM_tsense centralizes management of eight on-chip thermal sensors: one per CPU core, one within the GPU, two
near the memory I/O, and one near PLLX.”

In the “Table 241: Thermal Sensors in Tegra X1”, there are also 4 sensors present: TS_CPU0-TS_CPU3.

I want to understand that how the 4 sensor values are being combined to form the value under /sys/class/thermal/thermal_zone1/temp?

3

Hi asau,

Are you using the devkit or custom board for Jetson Nano?

The value presented in /sys/class/thermal/thermal_zone1/temp is an aggregated temperature for all four CPU cores.

May I know what’s your use case to get the details about /sys/class/thermal/thermal_zone1/temp?

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