Specifications

Hot Swap Backplane (HSBP) QSSC-S4R Technical Product Specification
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Figure 24. HSBP System Block Diagram
8.2.1 SAS Buses
The SAS buses are directly connected to the server board via the SAS RAID riser card that is plugged into the
designated PCI-Express* slot on the server board. As a result, the SAS RAID riser card provides all SAS functionality
and interfacing to the Hot Swap Backplane.
8.2.1.1 SAS Data
SAS data between drives and server board are routed across two 4-port internal SAS cables. The SAS cables connect
the Hot Swap Backplane to the PCI-Express* SAS Riser card.
8.2.2 Hot-swap Backplane
The SAS backplane routes data to/from each of the eight internal SAS drives from/to the SAS controller on the adapter
card. Data movement between the SAS drives on the Hot-swap backplane and the SAS controller is achieved through
two high-speed mini-SAS cables. These cables connect the PCI-Express* card to the Hot-swap backplane (HSBP).
There are a total of eight separate SAS buses or lanes. These buses are contained within the two high-speed cables. A
Molex* SFF 8086 mini connector (or Molex* SFF 8484 x SFF 8086*) is used to terminate each end of the cable
assembly to the SAS riser card and the HSBP.
8.2.3 Full-duplex Serial Mode Operation
Each SAS lane operates in full-duplex serial mode. In addition, each lane contains dedicated transmit and receive
differential pairs. The combination creates a total of four differential pairs on each of the two cables that routes data
directly to the eight SAS drives that are attached to its ports.
8.2.4 SAS Controller
The eight drives are connected directly to the Hot Swap Backplane (HSBP) via the 29-pin drive connector. The SAS
controller is used to control SAS traffic flow between drives and the SAS RAID riser card. A Vitesse* VSC410 module
communicates the presence and fault signals via a SES-2 interface (I2C* cable) or via a Serial General Purpose
Input/Output (SGPIO) interface thru the SAS cables. The mini connector routes the data to/from the SAS controller
card. All eight ports are used to connect directly to the eight hot-pluggable SAS (or SATA) drives with each drive
having a dedicated port.
All SAS channels on the Hot-swap backplane are capable of 6Gbps data transmission on either the transmission path
or the reception path.