SoM Temperature Sensor¶

The MitySOM-A10S features two (2) on-SoM temperature sensors which are both connected to the I2C0 HPS interface (Ball E20 = I2C0_SCL and Ball D20 = I2C0_SDA). They are accessible in the Critical Link kernel builds through a sysfs driver.

I2C0 Address	sysfs device	Sensor Part #	Description
0011000	hwmon1	LM94235	A10 CPU Temperature sensor
1001000	hwmon0	AT30TS750A	Ambient Board Temperature sensor

A10 CPU Temperature Sensor¶

This sensor monitors the "TEMPDIODE" output(s) directly from the Arria 10 SoC (balls H10 and H11) as well as it has it's own "local"/internal temperature sensor.

• Local/internal = temp1_input
• Arria 10 SoC = temp2_input

This sensor is accessed in Linux through the following commands

root@mitysom-a10s:~# cat /sys/class/hwmon/hwmon1/temp1_input
35250
root@mitysom-a10s:~# cat /sys/class/hwmon/hwmon1/temp2_input
49968

The "T_CRIT" output pin external to the SoM, J4 Pin 2, is connected to the open drain active low output pin on the LM95235 temperature sensor, and is asserted on Arria 10 over temperature conditions.

Ambient Board Temperature Sensor¶

This sensor is designed to monitor the ambient temperature conditions that the module is currently experiencing, not any one specific component of the module.

• This sensor is accessed in Linux through the following commands
  

  root@mitysom-a10s:~# cat /sys/class/hwmon/hwmon0/temp1_input
  35500
  

• The "alert" output is not connected