Card InterfacesRev 1.0
Mellanox Technologies
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2.1.2 PCI Express Interface

The ConnectX®-3 mezzanine cards support PCI Express 3.0 (1.1 and 2.0 compatible) . The device
can be either a master initiating the PCI Express bus operations or a slave responding to PCI bus
operations.

2.1.3 I2C-compatible Interface

A three-pin header on the mezzanine cards is provided as the I2C-compatible interface.
Figure 6: I2C Connector
2.2 Power
All adapter cards receive 12V and 3.3V power from the PCI Express connector. All other required
power voltages are generated by on-board switch mode regulators. See
Appendix A.2,“Specifications,” on page 30.
2.3 Memory
The mezzanine cards support multiple memory devices through the PCI Express, SPI (Flash), and
I2C-compatible interfaces.

2.3.1 System Memory

The mezzanine cards utilize the PCI Express interface to store and access fabric connection infor-
mation on the system memory.

2.3.2 SPI

The mezzanine cards include one SPI Flash device accessible via the Flash interface of the Con-
nectX®-3 device.