EE100X(4D) Devices EE100X(4D)

NAME

ee100x - DDR4 serial presence detect driver

SYNOPSIS

/dev/eeprom/ee100x/*/eeprom

DESCRIPTION

The ee100x driver supports the I2C EEPROMs found on DDR4 DIMMs. The
driver provides read-only access to the SPD (serial presence detect)
EEPROM through a character device powered by the eedev(4D) driver.
These devices are generally found at 7-bit addresses between 0x50 and
0x57. The lower three bits of the address are used to indicate which
DIMM the device is found on (ranging from 0 to 7).

The SPD device contains 512 bytes of memory that are organized into two
pages of 256 bytes each. Devices can be found under
/dev/eeprom/ee100x. Contents of the SPD data can be decoded with
libjedec(3LIB).

FILES

/dev/eeprom/spd511x/*/eeprom EEPROM character device file.

/kernel/drv/amd64/ee100x Device driver (x86)

SEE ALSO

libjedec(3LIB), eedev(4D), spd511x(4D), i2cadm(8)

Definitions of the EE1004-v 4 Kbit Serial Presence Detect (SPD) EEPROM
and TSE2004av 4 Kbit SPD EEPROM with Temperature Sensor (TS) for Memory
Module Applications, JESD21-C Release 26, JEDEC Solid State Technology
Association.

illumos October 4, 2025 illumos