Serial Presence Deduct ie SPD stands for standard way of accessing information about the memory module. Most Memory module manufactures store the SPD information into the EEROM of the module. The information sorted like module size, data and width and speed and voltage are very useful for configuration and management of the device.
SPD5 stands for Serial Presence Deduct. It has two serial interfaces SDA and SCL. It Has been developed with both I2C and I3C bus Interfaces. SPD5 Hub isolates the local devices. Local devices like temperature sensors(TS), Power Management IC (PMIC), and Registering Clock driver(RCD). The SPD5 hub is operating up to 12.5MHz on a I3C bus and 1 MHz on a I2C bus.
I3C/ I2C bus has two interfaces SDA and SCL. The host connected with the hub through the SDA line. SPD5 Hub is intended to interface to I2C/I3C basic buses which have multiple devices on the same bus. The device must be uniquely addressed.
The SPD5 hub passes through the commands from the host bus to the local bus based on the device address. Based on the below shown figure the SPD5 hub connects with host and local devices.