Manual browser: sdtemp(4)

SDTEMP(4) Kernel Interfaces Manual SDTEMP(4)


sdtempJEDEC JC-42.4 compatible memory module temperature sensors


sdtemp* at iic? addr 0x18
sdtemp* at iic? addr 0x19
sdtemp* at iic? addr 0x1a
sdtemp* at iic? addr 0x1b
sdtemp* at iic? addr 0x1c
sdtemp* at iic? addr 0x1d
sdtemp* at iic? addr 0x1e
sdtemp* at iic? addr 0x1f


The sdtemp driver provides support for the Microchip Technology MCP9805/98242 and other chips that conform to JEDEC Standard 21-C section 4.7. Memory module temperature sensors are optional on DDR2 and DDR3 SDRAM DIMMs. Sensors provided by this driver, including the on-chip thresholds for the Alarm Window and Critical level, are accessed through the envsys(4) API.

The sdtemp supports temperature ranges from -256 to +255 degrees C.

Chips supported by the sdtemp driver include:

  • Catalyst CAT34TS02 and CAT6095
  • Analog Devices ADT7408
  • Integrated Deviced Technology TSE2002B3 and TSE3000B3
  • Maxim MAX6604
  • Microchip Technology MCP9805, MCP9843, MCP98242, and MCP98243
  • NXP Semiconductors SE97 and SE98
  • STmicroelectronics STTS424 and STTS424E


The sdtemp device appeared in NetBSD 6.0.


Interrupt support is unimplemented.
January 8, 2011 NetBSD 7.0