Nvidia BlueField-2 User Manual page 95

Table D - 20-pin NC-SI Connector Pins

PACK_ID[2:0] signals allow for 8 unique card IDs. The system configurator sets the unique value per card via the connecting harness.
Pin#
1 GND
2 PACK_ID1, connected to BlueField-2 NIC_GPIO[47]
3 RBT_RXD0
4 RBT_REF_CLK
Pin Name
Ground
Input
Output
Input
IO
Ground
See the description above table regarding PACK_ID
Should be connected to the Primary controller NC-SI PACK_ID pins to set the appropriate
package ID.
PACK_ID0 should be connected to the endpoint device GPIO associated with Package
ID[0]. PACK_ID1 should be associated with Package ID0.
The baseboard should connect to GND or leave floating.
DPU should have a 4.7k PU.
Receive data Out 0. Data signals from the network controller to the BMC.
For baseboards, this pin should be connected between the baseboard NC-SI over RBT PHY
and the connector. This signal requires a 100 kΩ pull-down resistor to GND on the
baseboard between the BMC and the RBT isolator to prevent the signal from floating
when no card is installed.
For DPUs, this pin should be connected between the connector and the RBT PHY.
External termination is determined by the DPU RBT PHY requirements.
RBT Reference clock. Synchronous clock reference for receive, transmit, and control
interface. The clock should have a typical frequency of 50MHz ±50 ppm.
For baseboards, this pin should be connected between the baseboard NC-SI over RBT PHY
and the DPU cable connector. The RBT_REF_CLK should not be driven until 3.3V AUX is
present on the DPU. The RBT_REF_CLK should be continuous once it has started. For
Description/Comments
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