Nvidia BlueField-3 - PCI Express Interface; DDR5 SDRAM On-Board Memory; NC-SI Management Interface; UART Interface Connectivity

17
•
•
•
3.2.4 PCI Express Interface
The DPU Controller supports PCI Express Gen 5.0/4.0 through x16 edge connectors. Some cards
allow connectivity to an additional PCIe x16 Auxiliary card through the Cabline CA-II Plus
connectors.
The following lists PCIe interface features:
PCIe Gen 5.0, 4.0, 3.0, 2.0 and 1.1 compatible
2.5, 5.0, or 8.0, 16.0 or 32.0 GT/s link rate x16 lanes
Auto-negotiates to x16, x8, x4, x2, or x1
3.2.5 DDR5 SDRAM On-Board Memory
The DPU Controllers incorporate 20 units of DDR5 SDRAM for a total of 48GB @ 5200MT/s single or
dual channels. 64/128bit + 8bit ECC per channel, solder-down memory.
3.2.6 NC-SI Management Interface
The DPU Controller enables the connection of a Baseboard Management Controller (BMC) to a set of
Network Interface Controller (NICs) to enable out-of-band remote manageability. The NC-SI
management is supported over RMII and has a connector on the DPU Controller. Please refer to NC-SI
Management Interfacefor pins.
The maximum trace length on the board is 5.7inch.
3.2.7 UART Interface Connectivity
The UART debug interface on BlueField-3 boards can be accessed through a 20-pin NC-SI connector,
which is associated with the NIC BMC device.The connectivity is shown in the following table:
NC-SI Connector Pin # Signal on Board
12 GND
14 UART_TX
16 UART_RX
The USB to UART cable is not used for NC-SI management purposes.
It is prohibited to connect any RS-232 cable directly! Only TTL 3.3V voltage level cables are
supported.
Do not use the USB-to-UART cable for NC-SI management purposes.