Intel Netstructure MPRTM0020 Rear Transition module manual SAS Redriver, Board Status LEDs

Module Components

•+1.8V: The 1.8 V voltage is used as the input voltage to the SAS re-driver IC.

4.3.11SAS 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.

Figure 14. Physical Breakdown of SAS Ports Distribution

MPCBL0020 SBC
				0
SAS HDD		0	J31P31	1
				2
				3
4-Port
SAS HBA	0
	1
	2
	3

MPRTM0020 RTM

SAS
Re-driver		0	ConnectorSAS
Host Port	Port-B
		2
		3
A-Port (Not
Connected)

External cable to a SAS JBOD

4.3.12Board 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.

Intel NetStructure® MPRTM0020 Technical Product Specification – April 2006 27