Pin Description
DPU PCI Express x8 Pin Description
Pin # |
Signal Name |
Description |
Pin # |
Signal Name |
Description |
A1 |
PRSNT1# |
Mechanical Present |
B1 |
12V |
|
A2 |
12V |
B2 |
12V |
||
A3 |
12V |
B3 |
12V |
||
A4 |
GND |
B4 |
GND |
||
A5 |
TCK |
JTAG - Not Connected |
B5 |
SMCLK |
Host SMBus |
A6 |
TDI |
JTAG - Not Connected |
B6 |
SMDAT |
Host SMBus |
A7 |
TDO |
JTAG - Not Connected |
B7 |
GND |
|
A8 |
TMS |
JTAG - Not Connected |
B8 |
3.3V |
3.3V - Not Connected |
A9 |
3.3V |
3.3V - Not Connected |
B9 |
TRST# |
JTAG - Not Connected |
A10 |
3.3V |
3.3V - Not Connected |
B10 |
3.3V_AUX |
|
A11 |
PERST# |
PCIe Reset |
B11 |
WAKE#/RSVD |
|
A12 |
GND |
B12 |
RSVD |
||
A13 |
REFCLK+ |
Host Reference Clock |
B13 |
GND |
|
A14 |
REFCLK- |
Host Reference Clock |
B14 |
PETP0 |
|
A15 |
GND |
B15 |
PETN0 |
||
A16 |
PERP0 |
B16 |
GND |
||
A17 |
PERN0 |
B17 |
RSVD |
||
A18 |
GND |
B18 |
GND |
||
A19 |
RSVD |
B19 |
PETP1 |
||
A20 |
GND |
B20 |
PETN1 |
||
A21 |
PERP1 |
B21 |
GND |
||
A22 |
PERN1 |
B22 |
GND |
||
A23 |
GND |
B23 |
PETP2 |
||
A24 |
GND |
B24 |
PETN2 |
||
A25 |
PERP2 |
B25 |
GND |
||
A26 |
PERN2 |
B26 |
GND |
||
A27 |
GND |
B27 |
PETP3 |
||
A28 |
GND |
B28 |
PETN3 |
||
A29 |
PERP3 |
B29 |
GND |
||
A30 |
PERN3 |
B30 |
RSVD |
||
A31 |
GND |
B31 |
RSVD |
||
A32 |
RSVD |
B32 |
GND |
||
A33 |
RSVD |
B33 |
PETP4 |
||
A34 |
GND |
B34 |
PETN4 |
||
A35 |
PERP4 |
B35 |
GND |
||
A36 |
PERN4 |
B36 |
GND |
||
A37 |
GND |
B37 |
PETP5 |
||
A38 |
GND |
B38 |
PETN5 |
||
A39 |
PERP5 |
B39 |
GND |
||
A40 |
PERN5 |
B40 |
GND |
||
A41 |
GND |
B41 |
PETP6 |
||
A42 |
GND |
B42 |
PETN6 |
||
A43 |
PERP6 |
B43 |
GND |
||
A44 |
PERN6 |
B44 |
GND |
||
A45 |
GND |
B45 |
PETP7 |
||
A46 |
GND |
B46 |
PETN7 |
||
A47 |
PERP7 |
B47 |
GND |
||
A48 |
PERN7 |
B48 |
PRSNT2# |
Mechanical Present |
|
A49 |
GND |
B49 |
GND |
DPU PCI Express x16 Pin Description
Pin # |
Signal Name |
Description |
Pin # |
Signal Name |
Description |
A1 |
PRSNT1# |
Mechanical Present |
B1 |
12V |
|
A2 |
12V |
B2 |
12V |
||
A3 |
12V |
B3 |
12V |
||
A4 |
GND |
B4 |
GND |
||
A5 |
TCK |
JTAG - Not Connected |
B5 |
SMCLK |
Host SMBus |
A6 |
TDI |
JTAG - Not Connected |
B6 |
SMDAT |
Host SMBus |
A7 |
TDO |
JTAG - Not Connected |
B7 |
GND |
|
A8 |
TMS |
JTAG - Not Connected |
B8 |
3.3V |
3.3V - Not Connected |
A9 |
3.3V |
3.3V - Not Connected |
B9 |
TRST# |
JTAG - Not Connected |
A10 |
3.3V |
3.3V - Not Connected |
B10 |
3.3V_AUX |
|
A11 |
PERST# |
PCIe Reset |
B11 |
WAKE#/RSVD |
|
A12 |
GND |
B12 |
RSVD |
||
A13 |
REFCLK+ |
Host Reference Clock |
B13 |
GND |
|
A14 |
REFCLK- |
Host Reference Clock |
B14 |
PETP0 |
|
A15 |
GND |
B15 |
PETN0 |
||
A16 |
PERP0 |
B16 |
GND |
||
A17 |
PERN0 |
B17 |
RSVD |
||
A18 |
GND |
B18 |
GND |
||
A19 |
RSVD |
B19 |
PETP1 |
||
A20 |
GND |
B20 |
PETN1 |
||
A21 |
PERP1 |
B21 |
GND |
||
A22 |
PERN1 |
B22 |
GND |
||
A23 |
GND |
B23 |
PETP2 |
||
A24 |
GND |
B24 |
PETN2 |
||
A25 |
PERP2 |
B25 |
GND |
||
A26 |
PERN2 |
B26 |
GND |
||
A27 |
GND |
B27 |
PETP3 |
||
A28 |
GND |
B28 |
PETN3 |
||
A29 |
PERP3 |
B29 |
GND |
||
A30 |
PERN3 |
B30 |
RSVD |
||
A31 |
GND |
B31 |
RSVD |
||
A32 |
RSVD |
B32 |
GND |
||
A33 |
RSVD |
B33 |
PETP4 |
||
A34 |
GND |
B34 |
PETN4 |
||
A35 |
PERP4 |
B35 |
GND |
||
A36 |
PERN4 |
B36 |
GND |
||
A37 |
GND |
B37 |
PETP5 |
||
A38 |
GND |
B38 |
PETN5 |
||
A39 |
PERP5 |
B39 |
GND |
||
A40 |
PERN5 |
B40 |
GND |
||
A41 |
GND |
B41 |
PETP6 |
||
A42 |
GND |
B42 |
PETN6 |
||
A43 |
PERP6 |
B43 |
GND |
||
A44 |
PERN6 |
B44 |
GND |
||
A45 |
GND |
B45 |
PETP7 |
||
A46 |
GND |
B46 |
PETN7 |
||
A47 |
PERP7 |
B47 |
GND |
||
A48 |
PERN7 |
B48 |
RSVD |
||
A49 |
GND |
B49 |
GND |
||
A50 |
RSVD |
B50 |
PETP8 |
||
A51 |
GND |
B51 |
PETN8 |
||
A52 |
PERP8 |
B52 |
GND |
||
A53 |
PERN8 |
B53 |
GND |
||
A54 |
GND |
B54 |
PETP9 |
||
A55 |
GND |
B55 |
PETN9 |
||
A56 |
PERP9 |
B56 |
GND |
||
A57 |
PERN9 |
B57 |
GND |
||
A58 |
GND |
B58 |
PETP10 |
||
A59 |
GND |
B59 |
PETN10 |
||
A60 |
PERP10 |
B60 |
GND |
||
A61 |
PERN10 |
B61 |
GND |
||
A62 |
GND |
B62 |
PETP11 |
||
A63 |
GND |
B63 |
PETN11 |
||
A64 |
PERP11 |
B64 |
GND |
||
A65 |
PERN11 |
B65 |
GND |
||
A66 |
GND |
B66 |
PETP12 |
||
A67 |
GND |
B67 |
PETN12 |
||
A68 |
PERP12 |
B68 |
GND |
||
A69 |
PERN12 |
B69 |
GND |
||
A70 |
GND |
B70 |
PETP13 |
||
A71 |
GND |
B71 |
PETN13 |
||
A72 |
PERP13 |
B72 |
GND |
||
A73 |
PERN13 |
B73 |
GND |
||
A74 |
GND |
B74 |
PETP14 |
||
A75 |
GND |
B75 |
PETN14 |
||
A76 |
PERP14 |
B76 |
GND |
||
A77 |
PERN14 |
B77 |
GND |
||
A78 |
GND |
B78 |
PETP15 |
||
A79 |
GND |
B79 |
PETN15 |
||
A80 |
PERP15 |
B80 |
GND |
||
A81 |
PERN15 |
B81 |
PRSNT2# |
Mechanical Present |
|
A82 |
GND |
B82 |
RSVD |
The below table provides the External Power Supply pins of the external power supply interfaces on the DPU. For further details, please refer to External PCIe Power Supply Connector.
The mechanical pinout of the 6-pin external +12V power connector is shown below. The +12V connector is a GPU power PCIe standard connector. Care should be taken to ensure the power is applied to the correct pins as some 6-pin ATX type connector can have different pinouts.
Pin# |
Signal Name |
Description |
1 |
12V |
ATX Supplied 12V |
2 |
12V |
ATX Supplied 12V |
3 |
12V |
ATX Supplied 12V |
4 |
GND |
Power Return |
5 |
GND |
Power Return |
6 |
GND |
Power Return |
The below table provides the 4-pin vertical USB connector on the DPU. For further details, please refer to USB Interface.
Pin # |
Signal |
1 |
+5V_USB |
2 |
USB DP |
3 |
USB DN |
4 |
GND |
The below tables list the NC-SI management interface pinout descriptions per card type. Please follow the link to the table coinciding with the OPN you have purchased.
OPNs |
HW Versions |
Link |
MBF2H332A-AECOT, MBF2H332A-AECOT, MBF2H332A-AENOT |
A1xx - A3xx |
30-pin Connector: |
MBF2H332A-AECOT, MBF2H332A-AECOT, MBF2H332A-AENOT |
B1xx and Up |
30-pin Connector: |
MBF2M355A-VECOT, MBF2M355A-VESOT |
A1xx and Up |
|
MBF2H516A-CEEOT, MBF2H516A-CENOT MBF2M516A-CECOT, MBF2M516A-CEEOT MBF2M516A-CENOT, MBF2H512C-AECOT MBF2H516C-CECOT, MBF2H516C-CESOT MBF2H516C-CEUOT, MBF2M516C-CECOT MBF2M516C-CESOT, MBF2H512C-AESOT MBF2H512C-AEUOT |
A1xx and Up |
30-pin Connector: |
MBF2H532C-AECOT, MBF2H532C-AESOT |
A1xx - A5xx |
|
MBF2H536C-CECOT, MBF2H536C-CESOT |
A1xx - A7xx |
|
MBF2H532C-AECOT, MBF2H532C-AESOT MBF2H536C-CECOT, MBF2H536C-CESOT |
B1xx and Up |
20-pin Connector |
MBF2H536C-CEUOT |
A1xx and Up |
Table A - NC-SI Connector Pins
Pin# |
Signal Name |
I/O |
Description |
Comments |
1 |
REF_CLK |
Input |
50M REF CLK for NCSI BUS |
RBT Reference clock. Synchronous clock reference for receive, transmit and control interface. The clock shall have a typical frequency of 50MHz ±50 ppm. For baseboards, this pin shall be connected between the baseboard NC-SI over RBT PHY and the DPU cable connector. The RBT_REF_CLK shall not be driven until 3.3V AUX is present on the DPU. The RBT_REF_CLK shall be continuous once it has started. For DPUs, this pin shall be connected between the connector and the RBT PHY. No external termination is required. |
2 |
GND |
GND |
Ground |
|
3 |
ARB_IN |
Input |
NCSI hardware arbitration input |
NC-SI hardware arbitration input If the baseboard supports multiple DPU cards connected to the same RBT interface, it shall implement logic that connects the RBT_ARB_IN pin of the first populated DPU card to its RBT_ARB_OUT pin if it is the only card present or to the RBT_ARB_OUT pin of the next populated card and so on sequentially for all cards on the specified RBT bus to ensure the arbitration ring is complete. This logic shall bypass slots that are not populated or powered off. |
4 |
GND |
GND |
Ground |
|
5 |
ARB_OUT |
Output |
NCSI hardware arbitration output |
NC-SI hardware arbitration output. If the baseboard supports multiple DPU cards connected to the same RBT interface, it shall implement logic that connects the RBT_ARB_OUT pin of the first populated DPU card to its RBT_ARB_IN pin if it is the only card present or to the RBT_ARB_IN pin of the next populated card and so on sequentially for all cards on the specified RBT bus to ensure the arbitration ring is complete. This logic shall bypass slots that are not populated or powered off. |
6 |
GND |
GND |
Ground |
|
7 |
RX_D0 |
Output |
Receive data |
Output for SoC Receive data. Data signals from the network controller to the BMC. For baseboards, this pin shall 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 shall be connected between the connector and the RBT PHY. External termination determined by the DPU RBT PHY requirements. |
8 |
GND |
GND |
Ground |
|
9 |
RX_D1 |
Output |
Receive data |
Output for SoC Receive data. Data signals from the network controller to the BMC. For baseboards, this pin shall 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 shall be connected between the connector and the RBT PHY. External termination determined by the DPU RBT PHY requirements. |
10 |
GND |
GND |
Ground |
|
11 |
CRS_DV |
Output |
Carrier sense/Receive Data Valid |
Carrier sense/receive data valid. This signal is used to indicate to the baseboard that the carrier sense/receive data is valid. For baseboards, this pin shall be connected between the baseboard NC-SI over RBT PHY and the connector. This signal requires a 100 kΩ pull down resistor on the baseboard between the BMC and the RBT isolator to prevent the signal from floating when no DPU is installed. For DPUs, this pin shall be connected between the connector and the RBT PHY. External termination determined by the SmartNIC RBT PHY requirements. |
12 |
GND |
GND |
Ground |
|
13 |
TX_D0 |
Input |
Transmit data |
Input for SoC. Data signals from the BMC to the network controller. For baseboards, this pin shall 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 RBT isolator and the DPUcable connector to prevent the card-side signals from floating when the RBT signals are isolated. For DPUs, this pin shall be connected between the connector and the RBT PHY. External termination determined by the DPU RBT PHY requirements. |
14 |
GND |
GND |
Ground |
|
15 |
TX_D1 |
Input |
Transmit data |
Input for SoC. Data signals from the BMC to the network controller. For baseboards, this pin shall 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 RBT isolator and the DPUcable connector to prevent the card-side signals from floating when the RBT signals are isolated. For DPUs, this pin shall be connected between the connector and the RBT PHY. External termination determined by the DPU RBT PHY requirements. |
16 |
GND |
GND |
Ground |
|
17 |
TX_EN |
Input |
Transmit enable |
Transmit enable. For baseboards, this pin shall be connected between the baseboard NC-SI over RBT PHY and the connector. This signal requires a 100 kΩ pull down resistor to ground on the baseboard between the RBT isolator and the DPU cable connector to prevent the card-side signals from floating when the RBT signals are isolated. For DPUs, this pin shall be connected between the connector and the RBT PHY. External termination determined by the DPU RBT PHY requirements. |
18 |
GND |
GND |
Ground |
|
19 |
NC |
|||
20 |
NC |
|||
21 |
I2C_SDA |
Bidirectional |
I2C Serial Data |
GW_ARM1 |
22 |
GND |
GND |
Ground |
|
23 |
I2C_SCL |
Bidirectional |
I2C Serial Clock |
GW_ARM1 |
24 |
GND |
GND |
Ground |
|
25 |
GND |
GND |
Ground |
|
26 |
GND |
GND |
Ground |
|
27 |
NC |
|||
28 |
UART_TX |
Output |
Transmit data |
Output for SoC. 3.3V UART TX signal from the baseboard. |
29 |
NC |
|||
30 |
UART_RX |
Input |
Receive data |
3.3V UART RX signal to the baseboard. |
Table B - 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 # |
Pin Name |
I/O |
Description / Comments |
1 |
NCSI_REF_CLK |
Input |
50MHz REF CLK for NC-SI BUS |
2 |
GND |
GND |
Ground |
3 |
NCSI_ARB_IN |
Input |
NC-SI hardware arbitration input |
4 |
PACK_ID0, connected to BlueField-2 NIC_GPIO[49] |
Input |
See the note above table |
5 |
NCSI_ARB_OUT |
Output |
NC-SI hardware arbitration output |
6 |
PACK_ID1, connected to BlueField-2 NIC_GPIO[47] |
Input |
See the note above table |
7 |
NCSI_RX_D0 |
Output |
Receive Data Out 0 |
8 |
GND |
GND |
Ground |
9 |
NCSI_RX_D1 |
Output |
Receive Data Out 1 |
10 |
GND |
GND |
Ground |
11 |
NCSI_CRS_DV |
Output |
Carrier Sense / Receive Data Valid |
12 |
GND |
GND |
Ground |
13 |
NCSI_TX_D0 |
Input |
Transmit Data In 0 |
14 |
GND |
GND |
Ground |
15 |
NCSI_TX_D1 |
Input |
Transmit Data In 0 |
16 |
GND |
GND |
Ground |
17 |
NCSI_TX_EN |
Input |
Transmit Enable |
18 |
GND |
GND |
Ground |
19 |
Reserved |
||
20 |
SOFT_RST#, connected to BlueField-2 device pin HOST_GPIO[7] |
||
21 |
ARM_I2C1_SDA |
Input/Output |
Open-drain signal |
22 |
ARM_NSRST# |
Input/Output |
Open-drain signal |
23 |
ARM_I2C1_SCL |
Input/Output |
Open-drain signal |
24 |
PACK_ID2, connected to BlueField-2 device pin NIC_GPIO[46] |
Input |
See description above table |
25 |
GND |
GND |
Ground |
26 |
Not Connected |
||
27 |
Not Connected |
||
28 |
BF_UART0_TX |
Output |
UART transmit serial data output |
29 |
Not Connected |
||
30 |
BF_UART0_RX |
Input |
UART transmit serial data input |
Table C - 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 # |
Pin Name |
I/O |
Description / Comments |
1 |
NCSI_REF_CLK |
Input |
50MHz REF CLK for NC-SI BUS |
2 |
GND |
GND |
Ground |
3 |
NCSI_ARB_IN |
Input |
NC-SI hardware arbitration input |
4 |
PACK_ID0, connected to BlueField-2 device pin NIC_GPIO[49] |
Input |
See the note above table |
5 |
NCSI_ARB_OUT |
Output |
NC-SI hardware arbitration output |
6 |
PACK_ID1, connected to BlueField-2 device pin NIC_GPIO[47] |
Input |
See the note above table |
7 |
NCSI_RX_D0 |
Output |
Receive Data Out 0 |
8 |
GND |
GND |
Ground |
9 |
NCSI_RX_D1 |
Output |
Receive Data Out 1 |
10 |
GND |
GND |
Ground |
11 |
NCSI_CRS_DV |
Output |
Carrier Sense / Receive Data Valid |
12 |
GND |
GND |
Ground |
13 |
NCSI_TX_D0 |
Input |
Transmit Data In 0 |
14 |
GND |
GND |
Ground |
15 |
NCSI_TX_D1 |
Input |
Transmit Data In 0 |
16 |
GND |
GND |
Ground |
17 |
NCSI_TX_EN |
Input |
Transmit Enable |
18 |
GND |
GND |
Ground |
19 |
Reserved |
||
20 |
Reserved |
||
21 |
BMC_I2C2_SDA |
Input/Output |
Open-drain signal |
22 |
NIC_BMC_CTRL1, connected to BMC device pin W4 (Open Drain) |
Input/Output |
Open-drain signal |
23 |
BMC_I2C2_SCL |
Input/Output |
Open-drain signal |
24 |
PACK_ID2, connected to BlueField-2 device pin NIC_GPIO[46] |
Input |
See description above table |
25 |
GND |
GND |
Ground |
26 |
NIC_BMC_CTRL0, connected to BMC device pin Y3 (Open Drain) |
||
27 |
Not Connected |
||
28 |
BMC_TX5 |
Output |
UART transmit serial data output |
29 |
Not Connected |
||
30 |
BMC_RX5 |
Input |
UART transmit serial data input |
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# |
Pin Name |
IO |
Description/Comments |
1 |
GND |
Ground |
Ground |
2 |
PACK_ID1, connected to BlueField-2 NIC_GPIO[47] |
Input |
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. |
3 |
RBT_RXD0 |
Output |
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. |
4 |
RBT_REF_CLK |
Input |
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 DPUs, this pin should be connected between the connector and the RBT PHY. No external termination is required. 50MHz REF CLK for NC-SI BUS |
5 |
RBT_RXD1 |
Output |
Receive Data Out 1. 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. |
6 |
GND |
Ground |
Ground |
7 |
RBT_CRS_DV |
Output |
Carrier sense/receive data valid. This signal indicates to the baseboard that the carrier sense/receive data is valid. 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 on the baseboard between the BMC and the RBT isolator to prevent the signal from floating when no DPU 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. |
8 |
RBT_ISOLATE_N |
Output |
Signal used to indicate the SmartNIC has powered and is ready for NC-SI physical layer connection to be present. When low the baseboard circuitry will isolate the NC-SI connection to the SmartNIC. When high normal NC-SI RBT connectivity is available. Baseboards should terminate this with a 47K-100K PD resistor. SmartNICs should terminate with a 10k PU resistor. |
9 |
GND |
Ground |
Ground |
10 |
PACK_ID0, connected to BlueField-2 NIC_GPIO[49] |
Input |
See note above table regarding NC-SI 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 PACK_ID[1]. The baseboard should connect to GND or leave floating. DPU should have a 4.7k PU. |
11 |
NCSI_TX_EN |
Input |
Transmit enable. 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 ground on the baseboard between the RBT isolator and the DPU cable connector to prevent the card-side signals from floating when the RBT signals are isolated. For DPUs, this pin should be connected between the connector and the RBT PHY. External termination is determined by the DPU RBT PHY requirements. |
12 |
GND |
Ground |
Ground |
13 |
NCSI_TX_D0 |
Input |
Transmit Data In 0. Data signals from the BMC to the network controller. 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 RBT isolator and the DPUcable connector to prevent the card-side signals from floating when the RBT signals are isolated. For DPUs, this pin should be connected between the connector and the RBT PHY. External termination is determined by the DPU RBT PHY requirements. |
14 |
BMC_RX5 |
Input |
UART transmit serial data input. 3.3V UART TX signal from the baseboard Ground |
15 |
NCSI_TX_D1 |
Input |
Transmit Data In 0. Data signals from the BMC to the network controller. 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 RBT isolator and the DPUcable connector to prevent the card-side signals from floating when the RBT signals are isolated. For DPUs, this pin should be connected between the connector and the RBT PHY. External termination is determined by the DPU RBT PHY requirements. |
16 |
BMC_TX5 |
Output |
UART transmit serial data output. 3.3V UART TX signal to the baseboard. |
17 |
PRESENCE_N |
Output |
Presence of SmartNIC The baseboard should implement a 200 Ω series resistor and 4.7kohm pull-up resistor to 3.3V AUX. SmartNIC should tie this to GND. |
18 |
GND |
Ground |
Ground |
19 |
NCSI_ARB_IN |
Input |
NC-SI hardware arbitration input If the baseboard supports multiple DPU cards connected to the same RBT interface, it should implement logic that connects the RBT_ARB_IN pin of the first populated DPU card to its RBT_ARB_OUT pin if it is the only card present or to the RBT_ARB_OUT pin of the next populated card and so on sequentially for all cards on the specified RBT bus to ensure the arbitration ring is complete. This logic should bypass slots that are not populated or powered off. |
20 |
NCSI_ARB_OUT |
Output |
NC-SI hardware arbitration output. If the baseboard supports multiple DPU cards connected to the same RBT interface, it should implement logic that connects the RBT_ARB_OUT pin of the first populated DPU card to its RBT_ARB_IN pin if it is the only card present or to the RBT_ARB_IN pin of the next populated card and so on sequentially for all cards on the specified RBT bus to ensure the arbitration ring is complete. This logic should bypass slots that are not populated or powered off. |