08
8.2.1. Power supply management interface address
8.1 PMBus communication
The PMBus serial bus communication devices for I2C data in the power supply shall be compatible with both
SMBus 2.0 “high power” and I2C Vdd based power and drive. This bus shall operate at 3.3V but tolerant of 5V
signaling. The SMBus pull-ups are located on the motherboard and may be connected to 3.3V or 5V.
Two pins are allocated on the power supply. One pin is the serial clock (SMBus_SCL). The second pin is used
for serial data (SMBus_SDA). Both pins are bi-directional and are used to form a serial bus.
The device(s) in the power supply shall be located at an address(s) determined by addressing pins A0 and A1
on the power supply module. The circuits inside the power supply shall derive their power from the 5VSB bus.
Device(s) shall be powered from the system side of the 5VSB device. No pull-up resistors shall be on SCL or
SDA inside the power supply. There pull-up resistors should be located external to the power supply.
8.2 Power supply management interface
The device in the power supply shall derive its power off of the 5VSB output on the system side. It shall be
located at an address set by the A0 and A1 pins. Refer to the PMBus specification posted on the www.powerSIG.org
website for details on the power supply monitoring interface requirements. I2C is a SMBus interface used
to communicate power management information to the system.
Device address locations
PDB addressing A1/A0
Device Address
Housing
-
-
M1
1/1
B6h
M2
0/1
B2h
8. PMBus
Summary of Contents for GEMINI GM600-G
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