Adapter Card Interfaces
Rev 1.0
Mellanox Technologies
20
Figure 9: I
2
C Connector
4.2
Power
All adapter cards receive 12V and 3.3V power from the PCI Express Edge connector. All other
required power voltages are generated by on-board switch mode regulators. See “Specifications”
on page 25.
4.3
Memory
The adapter cards support multiple memory devices through the PCI Flash, and I2C-compatible
interfaces. The adapter card utilizes the PCI Express interface to store and access IB fabric and/or
EN fabric connection information and packet data on the system memory.
4.3.1 Flash
Each of the adapter cards include one 16MB SPI Flash device M25P16-VME6G device by ST
Microelectronics) accessible via the Flash interface of the MT25408B0 ConnectX-2 VPI device.
There is a jumper on each adapter card that indicates to the device whether an on-board Flash
device is to be used. Table 9 provides information on this jumper. See Figure 13,“Schematic of the
ConnectX-2 MHZH Adapter Card” for the jumper location.
4.3.2 EEPROM
Each board incorporates an EEPROM that is accessible through the I2C-compatible interface. The
EEPROM is used for storing the Vital Product Data (VPD). The VPD format adheres to the
PCI
Local Bus Specification Rev 2.3
VPD definition. The EEPROM capacity is 4Kb.
Table 9 - Jumper Configuration
Description
Option
Card Default
Configuration
Comments
Flash present/
not present
connection open – Flash present
connection shorted – Flash not present
Figure 10:
Flash Jumper
connection
open – Flash
present
Header 1x2
