Filter
Top Products
Intel NetStructure
®
MPRTM0020 Technical Product Specification – April 2006 27
Module Components
• +1.8V: The 1.8 V voltage is used as the input voltage to the SAS re-driver IC.
4.3.11 SAS Redriver
The MPCBL0020 Single Board Computer implements optional SAS storage access via the
MPRTM0020 RTM. SAS is a 3-Gbps SERDES style bus, and a redriver is added on the RTM to
effectively detect and correct the SAS OOB signals at a proper amplitude.
The specific SAS re-driver that was used is the PMC-Sierra* PM8380 Quad SMX 3G SATA/SAS
Mux/Demux. The RTM implements the PM8380 device as a 1:1 re-driver. The four host ports are
connected to the SBC via the Zone 3 connector.
The four SAS ports of the “B” Load-side Mux-port are connected to the External SAS connector.
The “A” Load-side Mux-port is left unconnected. The PM8380 has its configuration straps set to
operate in re-driving mode, rather than in Mux mode. The “B” Load-side Mux-port is configured
for the default SAS amplitude, pre-emphasis, and equalization.
Figure 14 illustrates the SAS port distribution on the RTM.
Note: Only three SAS ports are routed to the MPRRTM0020 RTM because the first SAS port from the
SAS HBA (port 0) is used for the on-board SAS hard drive on the MPCBL0020 SBC.
4.3.12 Board Status LEDs
The Hot Swap, Out of Service, and Health LEDs on the RTM faceplate are fronted by the
MPCBL0020 Single Board Computer. These LEDs have identical state to the LEDs on the SBC
faceplate and allow service personnel to verify the state of the board when servicing the board from
the rear of the chassis.
Figure 14. Physical Breakdown of SAS Ports Distribution
MPRTM0020 RTMMPRTM0020 RTMMPCBL0020 SBCMPCBL0020 SBC
4-Port
SAS HBA
4-Port
SAS HBA
SAS HDD
0
1
2
3
SAS
Re-driver
SAS
Re-driver
0
1
2
3
0
Host
Port
A-Port (Not
Connected)
0
1
2
3
B-Port
SAS Connector
External cable
to a SAS JBOD
J31P31